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Tracing updates:

Browse Source 
- Addition of multiprobes to kprobe and uprobe events
    Allows for more than one probe attached to the same location
 
  - Addition of adding immediates to probe parameters
 
  - Clean up of the recordmcount.c code. This brings us closer
    to merging recordmcount into objtool, and reuse code.
 
  - Other small clean ups
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Merge tag 'trace-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Addition of multiprobes to kprobe and uprobe events (allows for more
   than one probe attached to the same location)

 - Addition of adding immediates to probe parameters

 - Clean up of the recordmcount.c code. This brings us closer to merging
   recordmcount into objtool, and reuse code.

 - Other small clean ups

* tag 'trace-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
  selftests/ftrace: Update kprobe event error testcase
  tracing/probe: Reject exactly same probe event
  tracing/probe: Fix to allow user to enable events on unloaded modules
  selftests/ftrace: Select an existing function in kprobe_eventname test
  tracing/kprobe: Fix NULL pointer access in trace_porbe_unlink()
  tracing: Make sure variable reference alias has correct var_ref_idx
  tracing: Be more clever when dumping hex in __print_hex()
  ftrace: Simplify ftrace hash lookup code in clear_func_from_hash()
  tracing: Add "gfp_t" support in synthetic_events
  tracing: Rename tracing_reset() to tracing_reset_cpu()
  tracing: Document the stack trace algorithm in the comments
  tracing/arm64: Have max stack tracer handle the case of return address after data
  recordmcount: Clarify what cleanup() does
  recordmcount: Remove redundant cleanup() calls
  recordmcount: Kernel style formatting
  recordmcount: Kernel style function signature formatting
  recordmcount: Rewrite error/success handling
  selftests/ftrace: Add syntax error test for multiprobe
  selftests/ftrace: Add syntax error test for immediates
  selftests/ftrace: Add a testcase for kprobe multiprobe event
  ...
This commit is contained in:
Linus Torvalds 2019-09-20 11:19:48 -07:00
commit 45979a956b
22 changed files with 1199 additions and 406 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
Documentation/trace/kprobetrace.rst
View File

@ -52,6 +52,7 @@ Synopsis of kprobe_events
$retval : Fetch return value.(\*2)
$comm : Fetch current task comm.
+|-[u]OFFS(FETCHARG) : Fetch memory at FETCHARG +|- OFFS address.(\*3)(\*4)
\IMM : Store an immediate value to the argument.
NAME=FETCHARG : Set NAME as the argument name of FETCHARG.
FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types
(u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal types

1
Documentation/trace/uprobetracer.rst
View File

@ -45,6 +45,7 @@ Synopsis of uprobe_tracer
$retval : Fetch return value.(\*1)
$comm : Fetch current task comm.
+|-[u]OFFS(FETCHARG) : Fetch memory at FETCHARG +|- OFFS address.(\*2)(\*3)
\IMM : Store an immediate value to the argument.
NAME=FETCHARG : Set NAME as the argument name of FETCHARG.
FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types
(u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal types

13
arch/arm64/include/asm/ftrace.h
View File

@ -14,6 +14,19 @@
#define MCOUNT_ADDR ((unsigned long)_mcount)
#define MCOUNT_INSN_SIZE AARCH64_INSN_SIZE
/*
* Currently, gcc tends to save the link register after the local variables
* on the stack. This causes the max stack tracer to report the function
* frame sizes for the wrong functions. By defining
* ARCH_FTRACE_SHIFT_STACK_TRACER, it will tell the stack tracer to expect
* to find the return address on the stack after the local variables have
* been set up.
*
* Note, this may change in the future, and we will need to deal with that
* if it were to happen.
*/
#define ARCH_FTRACE_SHIFT_STACK_TRACER 1
#ifndef __ASSEMBLY__
#include <linux/compat.h>

56
kernel/kprobes.c
View File

@ -961,9 +961,16 @@ static struct kprobe *alloc_aggr_kprobe(struct kprobe *p)
#ifdef CONFIG_KPROBES_ON_FTRACE
static struct ftrace_ops kprobe_ftrace_ops __read_mostly = {
.func = kprobe_ftrace_handler,
.flags = FTRACE_OPS_FL_SAVE_REGS,
};
static struct ftrace_ops kprobe_ipmodify_ops __read_mostly = {
.func = kprobe_ftrace_handler,
.flags = FTRACE_OPS_FL_SAVE_REGS | FTRACE_OPS_FL_IPMODIFY,
};
static int kprobe_ipmodify_enabled;
static int kprobe_ftrace_enabled;
/* Must ensure p->addr is really on ftrace */
@ -976,58 +983,75 @@ static int prepare_kprobe(struct kprobe *p)
}
/* Caller must lock kprobe_mutex */
static int arm_kprobe_ftrace(struct kprobe *p)
static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops,
int *cnt)
{
int ret = 0;
ret = ftrace_set_filter_ip(&kprobe_ftrace_ops,
(unsigned long)p->addr, 0, 0);
ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 0, 0);
if (ret) {
pr_debug("Failed to arm kprobe-ftrace at %pS (%d)\n",
p->addr, ret);
return ret;
}
if (kprobe_ftrace_enabled == 0) {
ret = register_ftrace_function(&kprobe_ftrace_ops);
if (*cnt == 0) {
ret = register_ftrace_function(ops);
if (ret) {
pr_debug("Failed to init kprobe-ftrace (%d)\n", ret);
goto err_ftrace;
}
}
kprobe_ftrace_enabled++;
(*cnt)++;
return ret;
err_ftrace:
/*
* Note: Since kprobe_ftrace_ops has IPMODIFY set, and ftrace requires a
* non-empty filter_hash for IPMODIFY ops, we're safe from an accidental
* empty filter_hash which would undesirably trace all functions.
* At this point, sinec ops is not registered, we should be sefe from
* registering empty filter.
*/
ftrace_set_filter_ip(&kprobe_ftrace_ops, (unsigned long)p->addr, 1, 0);
ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0);
return ret;
}
static int arm_kprobe_ftrace(struct kprobe *p)
{
bool ipmodify = (p->post_handler != NULL);
return __arm_kprobe_ftrace(p,
ipmodify ? &kprobe_ipmodify_ops : &kprobe_ftrace_ops,
ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled);
}
/* Caller must lock kprobe_mutex */
static int disarm_kprobe_ftrace(struct kprobe *p)
static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops,
int *cnt)
{
int ret = 0;
if (kprobe_ftrace_enabled == 1) {
ret = unregister_ftrace_function(&kprobe_ftrace_ops);
if (*cnt == 1) {
ret = unregister_ftrace_function(ops);
if (WARN(ret < 0, "Failed to unregister kprobe-ftrace (%d)\n", ret))
return ret;
}
kprobe_ftrace_enabled--;
(*cnt)--;
ret = ftrace_set_filter_ip(&kprobe_ftrace_ops,
(unsigned long)p->addr, 1, 0);
ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0);
WARN_ONCE(ret < 0, "Failed to disarm kprobe-ftrace at %pS (%d)\n",
p->addr, ret);
return ret;
}
static int disarm_kprobe_ftrace(struct kprobe *p)
{
bool ipmodify = (p->post_handler != NULL);
return __disarm_kprobe_ftrace(p,
ipmodify ? &kprobe_ipmodify_ops : &kprobe_ftrace_ops,
ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled);
}
#else /* !CONFIG_KPROBES_ON_FTRACE */
#define prepare_kprobe(p) arch_prepare_kprobe(p)
#define arm_kprobe_ftrace(p) (-ENODEV)

6
kernel/trace/ftrace.c
View File

@ -6036,11 +6036,7 @@ clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash)
{
struct ftrace_func_entry *entry;
if (ftrace_hash_empty(hash))
return;
entry = __ftrace_lookup_ip(hash, func->ip);
entry = ftrace_lookup_ip(hash, func->ip);
/*
* Do not allow this rec to match again.
* Yeah, it may waste some memory, but will be removed

14
kernel/trace/trace.c
View File

@ -1854,7 +1854,7 @@ int __init register_tracer(struct tracer *type)
return ret;
}
void tracing_reset(struct trace_buffer *buf, int cpu)
static void tracing_reset_cpu(struct trace_buffer *buf, int cpu)
{
struct ring_buffer *buffer = buf->buffer;
@ -4251,7 +4251,7 @@ static int tracing_open(struct inode *inode, struct file *file)
if (cpu == RING_BUFFER_ALL_CPUS)
tracing_reset_online_cpus(trace_buf);
else
tracing_reset(trace_buf, cpu);
tracing_reset_cpu(trace_buf, cpu);
}
if (file->f_mode & FMODE_READ) {
@ -4815,15 +4815,15 @@ static const char readme_msg[] =
#endif
#endif /* CONFIG_STACK_TRACER */
#ifdef CONFIG_DYNAMIC_EVENTS
" dynamic_events\t\t- Add/remove/show the generic dynamic events\n"
" dynamic_events\t\t- Create/append/remove/show the generic dynamic events\n"
"\t\t\t Write into this file to define/undefine new trace events.\n"
#endif
#ifdef CONFIG_KPROBE_EVENTS
" kprobe_events\t\t- Add/remove/show the kernel dynamic events\n"
" kprobe_events\t\t- Create/append/remove/show the kernel dynamic events\n"
"\t\t\t Write into this file to define/undefine new trace events.\n"
#endif
#ifdef CONFIG_UPROBE_EVENTS
" uprobe_events\t\t- Add/remove/show the userspace dynamic events\n"
" uprobe_events\t\t- Create/append/remove/show the userspace dynamic events\n"
"\t\t\t Write into this file to define/undefine new trace events.\n"
#endif
#if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)
@ -4848,7 +4848,7 @@ static const char readme_msg[] =
#else
"\t $stack<index>, $stack, $retval, $comm,\n"
#endif
"\t +|-[u]<offset>(<fetcharg>)\n"
"\t +|-[u]<offset>(<fetcharg>), \\imm-value, \\\"imm-string\"\n"
"\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n"
"\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n"
"\t <type>\\[<array-size>\\]\n"
@ -6742,7 +6742,7 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
if (iter->cpu_file == RING_BUFFER_ALL_CPUS)
tracing_reset_online_cpus(&tr->max_buffer);
else
tracing_reset(&tr->max_buffer, iter->cpu_file);
tracing_reset_cpu(&tr->max_buffer, iter->cpu_file);
}
break;
}

1
kernel/trace/trace.h
View File

@ -677,7 +677,6 @@ trace_buffer_iter(struct trace_iterator *iter, int cpu)
int tracer_init(struct tracer *t, struct trace_array *tr);
int tracing_is_enabled(void);
void tracing_reset(struct trace_buffer *buf, int cpu);
void tracing_reset_online_cpus(struct trace_buffer *buf);
void tracing_reset_current(int cpu);
void tracing_reset_all_online_cpus(void);

10
kernel/trace/trace_dynevent.c
View File

@ -47,6 +47,7 @@ int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type)
return -EINVAL;
event++;
}
argc--; argv++;
p = strchr(event, '/');
if (p) {
@ -61,10 +62,13 @@ int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type)
for_each_dyn_event_safe(pos, n) {
if (type && type != pos->ops)
continue;
if (pos->ops->match(system, event, pos)) {
ret = pos->ops->free(pos);
if (!pos->ops->match(system, event,
argc, (const char **)argv, pos))
continue;
ret = pos->ops->free(pos);
if (ret)
break;
}
}
mutex_unlock(&event_mutex);

7
kernel/trace/trace_dynevent.h
View File

@ -31,8 +31,9 @@ struct dyn_event;
* @is_busy: Check whether given event is busy so that it can not be deleted.
* Return true if it is busy, otherwides false.
* @free: Delete the given event. Return 0 if success, otherwides error.
* @match: Check whether given event and system name match this event.
* Return true if it matches, otherwides false.
* @match: Check whether given event and system name match this event. The argc
* and argv is used for exact match. Return true if it matches, otherwides
* false.
*
* Except for @create, these methods are called under holding event_mutex.
*/
@ -43,7 +44,7 @@ struct dyn_event_operations {
bool (*is_busy)(struct dyn_event *ev);
int (*free)(struct dyn_event *ev);
bool (*match)(const char *system, const char *event,
struct dyn_event *ev);
int argc, const char **argv, struct dyn_event *ev);
};
/* Register new dyn_event type -- must be called at first */

25
kernel/trace/trace_events_hist.c
View File

@ -13,6 +13,10 @@
#include <linux/rculist.h>
#include <linux/tracefs.h>
/* for gfp flag names */
#include <linux/trace_events.h>
#include <trace/events/mmflags.h>
#include "tracing_map.h"
#include "trace.h"
#include "trace_dynevent.h"
@ -374,7 +378,7 @@ static int synth_event_show(struct seq_file *m, struct dyn_event *ev);
static int synth_event_release(struct dyn_event *ev);
static bool synth_event_is_busy(struct dyn_event *ev);
static bool synth_event_match(const char *system, const char *event,
struct dyn_event *ev);
int argc, const char **argv, struct dyn_event *ev);
static struct dyn_event_operations synth_event_ops = {
.create = synth_event_create,
@ -422,7 +426,7 @@ static bool synth_event_is_busy(struct dyn_event *ev)
}
static bool synth_event_match(const char *system, const char *event,
struct dyn_event *ev)
int argc, const char **argv, struct dyn_event *ev)
{
struct synth_event *sev = to_synth_event(ev);
@ -752,6 +756,8 @@ static int synth_field_size(char *type)
size = sizeof(unsigned long);
else if (strcmp(type, "pid_t") == 0)
size = sizeof(pid_t);
else if (strcmp(type, "gfp_t") == 0)
size = sizeof(gfp_t);
else if (synth_field_is_string(type))
size = synth_field_string_size(type);
@ -792,6 +798,8 @@ static const char *synth_field_fmt(char *type)
fmt = "%lu";
else if (strcmp(type, "pid_t") == 0)
fmt = "%d";
else if (strcmp(type, "gfp_t") == 0)
fmt = "%x";
else if (synth_field_is_string(type))
fmt = "%s";
@ -834,9 +842,20 @@ static enum print_line_t print_synth_event(struct trace_iterator *iter,
i == se->n_fields - 1 ? "" : " ");
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
} else {
struct trace_print_flags __flags[] = {
__def_gfpflag_names, {-1, NULL} };
trace_seq_printf(s, print_fmt, se->fields[i]->name,
entry->fields[n_u64],
i == se->n_fields - 1 ? "" : " ");
if (strcmp(se->fields[i]->type, "gfp_t") == 0) {
trace_seq_puts(s, " (");
trace_print_flags_seq(s, "|",
entry->fields[n_u64],
__flags);
trace_seq_putc(s, ')');
}
n_u64++;
}
}
@ -2785,6 +2804,8 @@ static struct hist_field *create_alias(struct hist_trigger_data *hist_data,
return NULL;
}
alias->var_ref_idx = var_ref->var_ref_idx;
return alias;
}

268
kernel/trace/trace_kprobe.c
View File

@ -39,7 +39,7 @@ static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev);
static int trace_kprobe_release(struct dyn_event *ev);
static bool trace_kprobe_is_busy(struct dyn_event *ev);
static bool trace_kprobe_match(const char *system, const char *event,
struct dyn_event *ev);
int argc, const char **argv, struct dyn_event *ev);
static struct dyn_event_operations trace_kprobe_ops = {
.create = trace_kprobe_create,
@ -137,13 +137,36 @@ static bool trace_kprobe_is_busy(struct dyn_event *ev)
return trace_probe_is_enabled(&tk->tp);
}
static bool trace_kprobe_match_command_head(struct trace_kprobe *tk,
int argc, const char **argv)
{
char buf[MAX_ARGSTR_LEN + 1];
if (!argc)
return true;
if (!tk->symbol)
snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr);
else if (tk->rp.kp.offset)
snprintf(buf, sizeof(buf), "%s+%u",
trace_kprobe_symbol(tk), tk->rp.kp.offset);
else
snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk));
if (strcmp(buf, argv[0]))
return false;
argc--; argv++;
return trace_probe_match_command_args(&tk->tp, argc, argv);
}
static bool trace_kprobe_match(const char *system, const char *event,
struct dyn_event *ev)
int argc, const char **argv, struct dyn_event *ev)
{
struct trace_kprobe *tk = to_trace_kprobe(ev);
return strcmp(trace_probe_name(&tk->tp), event) == 0 &&
(!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0);
(!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) &&
trace_kprobe_match_command_head(tk, argc, argv);
}
static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
@ -180,20 +203,33 @@ unsigned long trace_kprobe_address(struct trace_kprobe *tk)
return addr;
}
static nokprobe_inline struct trace_kprobe *
trace_kprobe_primary_from_call(struct trace_event_call *call)
{
struct trace_probe *tp;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return NULL;
return container_of(tp, struct trace_kprobe, tp);
}
bool trace_kprobe_on_func_entry(struct trace_event_call *call)
{
struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
return kprobe_on_func_entry(tk->rp.kp.addr,
return tk ? kprobe_on_func_entry(tk->rp.kp.addr,
tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
tk->rp.kp.addr ? 0 : tk->rp.kp.offset);
tk->rp.kp.addr ? 0 : tk->rp.kp.offset) : false;
}
bool trace_kprobe_error_injectable(struct trace_event_call *call)
{
struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
return within_error_injection_list(trace_kprobe_address(tk));
return tk ? within_error_injection_list(trace_kprobe_address(tk)) :
false;
}
static int register_kprobe_event(struct trace_kprobe *tk);
@ -291,32 +327,68 @@ static inline int __enable_trace_kprobe(struct trace_kprobe *tk)
return ret;
}
static void __disable_trace_kprobe(struct trace_probe *tp)
{
struct trace_probe *pos;
struct trace_kprobe *tk;
list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
tk = container_of(pos, struct trace_kprobe, tp);
if (!trace_kprobe_is_registered(tk))
continue;
if (trace_kprobe_is_return(tk))
disable_kretprobe(&tk->rp);
else
disable_kprobe(&tk->rp.kp);
}
}
/*
* Enable trace_probe
* if the file is NULL, enable "perf" handler, or enable "trace" handler.
*/
static int
enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
static int enable_trace_kprobe(struct trace_event_call *call,
struct trace_event_file *file)
{
bool enabled = trace_probe_is_enabled(&tk->tp);
struct trace_probe *pos, *tp;
struct trace_kprobe *tk;
bool enabled;
int ret = 0;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return -ENODEV;
enabled = trace_probe_is_enabled(tp);
/* This also changes "enabled" state */
if (file) {
ret = trace_probe_add_file(&tk->tp, file);
ret = trace_probe_add_file(tp, file);
if (ret)
return ret;
} else
trace_probe_set_flag(&tk->tp, TP_FLAG_PROFILE);
trace_probe_set_flag(tp, TP_FLAG_PROFILE);
if (enabled)
return 0;
ret = __enable_trace_kprobe(tk);
list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
tk = container_of(pos, struct trace_kprobe, tp);
if (trace_kprobe_has_gone(tk))
continue;
ret = __enable_trace_kprobe(tk);
if (ret)
break;
enabled = true;
}
if (ret) {
/* Failed to enable one of them. Roll back all */
if (enabled)
__disable_trace_kprobe(tp);
if (file)
trace_probe_remove_file(&tk->tp, file);
trace_probe_remove_file(tp, file);
else
trace_probe_clear_flag(&tk->tp, TP_FLAG_PROFILE);
trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
}
return ret;
@ -326,11 +398,14 @@ enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
* Disable trace_probe
* if the file is NULL, disable "perf" handler, or disable "trace" handler.
*/
static int
disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
static int disable_trace_kprobe(struct trace_event_call *call,
struct trace_event_file *file)
{
struct trace_probe *tp = &tk->tp;
int ret = 0;
struct trace_probe *tp;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return -ENODEV;
if (file) {
if (!trace_probe_get_file_link(tp, file))
@ -341,12 +416,8 @@ disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
} else
trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
if (!trace_probe_is_enabled(tp) && trace_kprobe_is_registered(tk)) {
if (trace_kprobe_is_return(tk))
disable_kretprobe(&tk->rp);
else
disable_kprobe(&tk->rp.kp);
}
if (!trace_probe_is_enabled(tp))
__disable_trace_kprobe(tp);
out:
if (file)
@ -358,7 +429,7 @@ disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
*/
trace_probe_remove_file(tp, file);
return ret;
return 0;
}
#if defined(CONFIG_KPROBES_ON_FTRACE) && \
@ -437,6 +508,10 @@ static void __unregister_trace_kprobe(struct trace_kprobe *tk)
/* Unregister a trace_probe and probe_event */
static int unregister_trace_kprobe(struct trace_kprobe *tk)
{
/* If other probes are on the event, just unregister kprobe */
if (trace_probe_has_sibling(&tk->tp))
goto unreg;
/* Enabled event can not be unregistered */
if (trace_probe_is_enabled(&tk->tp))
return -EBUSY;
@ -445,12 +520,81 @@ static int unregister_trace_kprobe(struct trace_kprobe *tk)
if (unregister_kprobe_event(tk))
return -EBUSY;
unreg:
__unregister_trace_kprobe(tk);
dyn_event_remove(&tk->devent);
trace_probe_unlink(&tk->tp);
return 0;
}
static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig,
struct trace_kprobe *comp)
{
struct trace_probe_event *tpe = orig->tp.event;
struct trace_probe *pos;
int i;
list_for_each_entry(pos, &tpe->probes, list) {
orig = container_of(pos, struct trace_kprobe, tp);
if (strcmp(trace_kprobe_symbol(orig),
trace_kprobe_symbol(comp)) ||
trace_kprobe_offset(orig) != trace_kprobe_offset(comp))
continue;
/*
* trace_probe_compare_arg_type() ensured that nr_args and
* each argument name and type are same. Let's compare comm.
*/
for (i = 0; i < orig->tp.nr_args; i++) {
if (strcmp(orig->tp.args[i].comm,
comp->tp.args[i].comm))
continue;
}
return true;
}
return false;
}
static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to)
{
int ret;
ret = trace_probe_compare_arg_type(&tk->tp, &to->tp);
if (ret) {
/* Note that argument starts index = 2 */
trace_probe_log_set_index(ret + 1);
trace_probe_log_err(0, DIFF_ARG_TYPE);
return -EEXIST;
}
if (trace_kprobe_has_same_kprobe(to, tk)) {
trace_probe_log_set_index(0);
trace_probe_log_err(0, SAME_PROBE);
return -EEXIST;
}
/* Append to existing event */
ret = trace_probe_append(&tk->tp, &to->tp);
if (ret)
return ret;
/* Register k*probe */
ret = __register_trace_kprobe(tk);
if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
ret = 0;
}
if (ret)
trace_probe_unlink(&tk->tp);
else
dyn_event_add(&tk->devent);
return ret;
}
/* Register a trace_probe and probe_event */
static int register_trace_kprobe(struct trace_kprobe *tk)
{
@ -459,14 +603,17 @@ static int register_trace_kprobe(struct trace_kprobe *tk)
mutex_lock(&event_mutex);
/* Delete old (same name) event if exist */
old_tk = find_trace_kprobe(trace_probe_name(&tk->tp),
trace_probe_group_name(&tk->tp));
if (old_tk) {
ret = unregister_trace_kprobe(old_tk);
if (ret < 0)
goto end;
free_trace_kprobe(old_tk);
if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) {
trace_probe_log_set_index(0);
trace_probe_log_err(0, DIFF_PROBE_TYPE);
ret = -EEXIST;
} else {
ret = append_trace_kprobe(tk, old_tk);
}
goto end;
}
/* Register new event */
@ -700,7 +847,7 @@ static int trace_kprobe_create(int argc, const char *argv[])
trace_probe_log_err(0, BAD_INSN_BNDRY);
else if (ret == -ENOENT)
trace_probe_log_err(0, BAD_PROBE_ADDR);
else if (ret != -ENOMEM)
else if (ret != -ENOMEM && ret != -EEXIST)
trace_probe_log_err(0, FAIL_REG_PROBE);
goto error;
}
@ -965,6 +1112,9 @@ retry:
case FETCH_OP_COMM:
val = (unsigned long)current->comm;
break;
case FETCH_OP_DATA:
val = (unsigned long)code->data;
break;
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
case FETCH_OP_ARG:
val = regs_get_kernel_argument(regs, code->param);
@ -1089,7 +1239,10 @@ print_kprobe_event(struct trace_iterator *iter, int flags,
struct trace_probe *tp;
field = (struct kprobe_trace_entry_head *)iter->ent;
tp = container_of(event, struct trace_probe, call.event);
tp = trace_probe_primary_from_call(
container_of(event, struct trace_event_call, event));
if (WARN_ON_ONCE(!tp))
goto out;
trace_seq_printf(s, "%s: (", trace_probe_name(tp));
@ -1116,7 +1269,10 @@ print_kretprobe_event(struct trace_iterator *iter, int flags,
struct trace_probe *tp;
field = (struct kretprobe_trace_entry_head *)iter->ent;
tp = container_of(event, struct trace_probe, call.event);
tp = trace_probe_primary_from_call(
container_of(event, struct trace_event_call, event));
if (WARN_ON_ONCE(!tp))
goto out;
trace_seq_printf(s, "%s: (", trace_probe_name(tp));
@ -1145,23 +1301,31 @@ static int kprobe_event_define_fields(struct trace_event_call *event_call)
{
int ret;
struct kprobe_trace_entry_head field;
struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
struct trace_probe *tp;
tp = trace_probe_primary_from_call(event_call);
if (WARN_ON_ONCE(!tp))
return -ENOENT;
DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp);
return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
}
static int kretprobe_event_define_fields(struct trace_event_call *event_call)
{
int ret;
struct kretprobe_trace_entry_head field;
struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
struct trace_probe *tp;
tp = trace_probe_primary_from_call(event_call);
if (WARN_ON_ONCE(!tp))
return -ENOENT;
DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp);
return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
}
#ifdef CONFIG_PERF_EVENTS
@ -1289,20 +1453,19 @@ int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
static int kprobe_register(struct trace_event_call *event,
enum trace_reg type, void *data)
{
struct trace_kprobe *tk = (struct trace_kprobe *)event->data;
struct trace_event_file *file = data;
switch (type) {
case TRACE_REG_REGISTER:
return enable_trace_kprobe(tk, file);
return enable_trace_kprobe(event, file);
case TRACE_REG_UNREGISTER:
return disable_trace_kprobe(tk, file);
return disable_trace_kprobe(event, file);
#ifdef CONFIG_PERF_EVENTS
case TRACE_REG_PERF_REGISTER:
return enable_trace_kprobe(tk, NULL);
return enable_trace_kprobe(event, NULL);
case TRACE_REG_PERF_UNREGISTER:
return disable_trace_kprobe(tk, NULL);
return disable_trace_kprobe(event, NULL);
case TRACE_REG_PERF_OPEN:
case TRACE_REG_PERF_CLOSE:
case TRACE_REG_PERF_ADD:
@ -1369,7 +1532,6 @@ static inline void init_trace_event_call(struct trace_kprobe *tk)
call->flags = TRACE_EVENT_FL_KPROBE;
call->class->reg = kprobe_register;
call->data = tk;
}
static int register_kprobe_event(struct trace_kprobe *tk)
@ -1432,7 +1594,9 @@ void destroy_local_trace_kprobe(struct trace_event_call *event_call)
{
struct trace_kprobe *tk;
tk = container_of(event_call, struct trace_kprobe, tp.call);
tk = trace_kprobe_primary_from_call(event_call);
if (unlikely(!tk))
return;
if (trace_probe_is_enabled(&tk->tp)) {
WARN_ON(1);
@ -1577,7 +1741,8 @@ static __init int kprobe_trace_self_tests_init(void)
pr_warn("error on getting probe file.\n");
warn++;
} else
enable_trace_kprobe(tk, file);
enable_trace_kprobe(
trace_probe_event_call(&tk->tp), file);
}
}
@ -1598,7 +1763,8 @@ static __init int kprobe_trace_self_tests_init(void)
pr_warn("error on getting probe file.\n");
warn++;
} else
enable_trace_kprobe(tk, file);
enable_trace_kprobe(
trace_probe_event_call(&tk->tp), file);
}
}
@ -1631,7 +1797,8 @@ static __init int kprobe_trace_self_tests_init(void)
pr_warn("error on getting probe file.\n");
warn++;
} else
disable_trace_kprobe(tk, file);
disable_trace_kprobe(
trace_probe_event_call(&tk->tp), file);
}
tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
@ -1649,7 +1816,8 @@ static __init int kprobe_trace_self_tests_init(void)
pr_warn("error on getting probe file.\n");
warn++;
} else
disable_trace_kprobe(tk, file);
disable_trace_kprobe(
trace_probe_event_call(&tk->tp), file);
}
ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe);

6
kernel/trace/trace_output.c
View File

@ -219,10 +219,10 @@ trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
{
int i;
const char *ret = trace_seq_buffer_ptr(p);
const char *fmt = concatenate ? "%*phN" : "%*ph";
for (i = 0; i < buf_len; i++)
trace_seq_printf(p, "%s%2.2x", concatenate || i == 0 ? "" : " ",
buf[i]);
for (i = 0; i < buf_len; i += 16)
trace_seq_printf(p, fmt, min(buf_len - i, 16), &buf[i]);
trace_seq_putc(p, 0);
return ret;

178
kernel/trace/trace_probe.c
View File

@ -316,6 +316,29 @@ inval_var:
return -EINVAL;
}
static int str_to_immediate(char *str, unsigned long *imm)
{
if (isdigit(str[0]))
return kstrtoul(str, 0, imm);
else if (str[0] == '-')
return kstrtol(str, 0, (long *)imm);
else if (str[0] == '+')
return kstrtol(str + 1, 0, (long *)imm);
return -EINVAL;
}
static int __parse_imm_string(char *str, char **pbuf, int offs)
{
size_t len = strlen(str);
if (str[len - 1] != '"') {
trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE);
return -EINVAL;
}
*pbuf = kstrndup(str, len - 1, GFP_KERNEL);
return 0;
}
/* Recursive argument parser */
static int
parse_probe_arg(char *arg, const struct fetch_type *type,
@ -430,7 +453,8 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
ret = parse_probe_arg(arg, t2, &code, end, flags, offs);
if (ret)
break;
if (code->op == FETCH_OP_COMM) {
if (code->op == FETCH_OP_COMM ||
code->op == FETCH_OP_DATA) {
trace_probe_log_err(offs, COMM_CANT_DEREF);
return -EINVAL;
}
@ -444,6 +468,21 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
code->offset = offset;
}
break;
case '\\': /* Immediate value */
if (arg[1] == '"') { /* Immediate string */
ret = __parse_imm_string(arg + 2, &tmp, offs + 2);
if (ret)
break;
code->op = FETCH_OP_DATA;
code->data = tmp;
} else {
ret = str_to_immediate(arg + 1, &code->immediate);
if (ret)
trace_probe_log_err(offs + 1, BAD_IMM);
else
code->op = FETCH_OP_IMM;
}
break;
}
if (!ret && code->op == FETCH_OP_NOP) {
/* Parsed, but do not find fetch method */
@ -542,8 +581,11 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
}
}
/* Since $comm can not be dereferred, we can find $comm by strcmp */
if (strcmp(arg, "$comm") == 0) {
/*
* Since $comm and immediate string can not be dereferred,
* we can find those by strcmp.
*/
if (strcmp(arg, "$comm") == 0 || strncmp(arg, "\\\"", 2) == 0) {
/* The type of $comm must be "string", and not an array. */
if (parg->count || (t && strcmp(t, "string")))
return -EINVAL;
@ -580,7 +622,8 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
if (!strcmp(parg->type->name, "string") ||
!strcmp(parg->type->name, "ustring")) {
if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF &&
code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM) {
code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM &&
code->op != FETCH_OP_DATA) {
trace_probe_log_err(offset + (t ? (t - arg) : 0),
BAD_STRING);
ret = -EINVAL;
@ -589,9 +632,10 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
if ((code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM) ||
parg->count) {
/*
* IMM and COMM is pointing actual address, those must
* be kept, and if parg->count != 0, this is an array
* of string pointers instead of string address itself.
* IMM, DATA and COMM is pointing actual address, those
* must be kept, and if parg->count != 0, this is an
* array of string pointers instead of string address
* itself.
*/
code++;
if (code->op != FETCH_OP_NOP) {
@ -665,7 +709,8 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
fail:
if (ret) {
for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
if (code->op == FETCH_NOP_SYMBOL)
if (code->op == FETCH_NOP_SYMBOL ||
code->op == FETCH_OP_DATA)
kfree(code->data);
}
kfree(tmp);
@ -736,7 +781,8 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
struct fetch_insn *code = arg->code;
while (code && code->op != FETCH_OP_END) {
if (code->op == FETCH_NOP_SYMBOL)
if (code->op == FETCH_NOP_SYMBOL ||
code->op == FETCH_OP_DATA)
kfree(code->data);
code++;
}
@ -886,44 +932,85 @@ int traceprobe_define_arg_fields(struct trace_event_call *event_call,
return 0;
}
static void trace_probe_event_free(struct trace_probe_event *tpe)
{
kfree(tpe->class.system);
kfree(tpe->call.name);
kfree(tpe->call.print_fmt);
kfree(tpe);
}
int trace_probe_append(struct trace_probe *tp, struct trace_probe *to)
{
if (trace_probe_has_sibling(tp))
return -EBUSY;
list_del_init(&tp->list);
trace_probe_event_free(tp->event);
tp->event = to->event;
list_add_tail(&tp->list, trace_probe_probe_list(to));
return 0;
}
void trace_probe_unlink(struct trace_probe *tp)
{
list_del_init(&tp->list);
if (list_empty(trace_probe_probe_list(tp)))
trace_probe_event_free(tp->event);
tp->event = NULL;
}
void trace_probe_cleanup(struct trace_probe *tp)
{
struct trace_event_call *call = trace_probe_event_call(tp);
int i;
for (i = 0; i < tp->nr_args; i++)
traceprobe_free_probe_arg(&tp->args[i]);
if (call->class)
kfree(call->class->system);
kfree(call->name);
kfree(call->print_fmt);
if (tp->event)
trace_probe_unlink(tp);
}
int trace_probe_init(struct trace_probe *tp, const char *event,
const char *group)
{
struct trace_event_call *call = trace_probe_event_call(tp);
struct trace_event_call *call;
int ret = 0;
if (!event || !group)
return -EINVAL;
call->class = &tp->class;
call->name = kstrdup(event, GFP_KERNEL);
if (!call->name)
tp->event = kzalloc(sizeof(struct trace_probe_event), GFP_KERNEL);
if (!tp->event)
return -ENOMEM;
tp->class.system = kstrdup(group, GFP_KERNEL);
if (!tp->class.system) {
kfree(call->name);
call->name = NULL;
return -ENOMEM;
INIT_LIST_HEAD(&tp->event->files);
INIT_LIST_HEAD(&tp->event->class.fields);
INIT_LIST_HEAD(&tp->event->probes);
INIT_LIST_HEAD(&tp->list);
list_add(&tp->event->probes, &tp->list);
call = trace_probe_event_call(tp);
call->class = &tp->event->class;
call->name = kstrdup(event, GFP_KERNEL);
if (!call->name) {
ret = -ENOMEM;
goto error;
}
tp->event->class.system = kstrdup(group, GFP_KERNEL);
if (!tp->event->class.system) {
ret = -ENOMEM;
goto error;
}
INIT_LIST_HEAD(&tp->files);
INIT_LIST_HEAD(&tp->class.fields);
return 0;
error:
trace_probe_cleanup(tp);
return ret;
}
int trace_probe_register_event_call(struct trace_probe *tp)
@ -952,7 +1039,7 @@ int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file)
link->file = file;
INIT_LIST_HEAD(&link->list);
list_add_tail_rcu(&link->list, &tp->files);
list_add_tail_rcu(&link->list, &tp->event->files);
trace_probe_set_flag(tp, TP_FLAG_TRACE);
return 0;
}
@ -983,8 +1070,45 @@ int trace_probe_remove_file(struct trace_probe *tp,
synchronize_rcu();
kfree(link);
if (list_empty(&tp->files))
if (list_empty(&tp->event->files))
trace_probe_clear_flag(tp, TP_FLAG_TRACE);
return 0;
}
/*
* Return the smallest index of different type argument (start from 1).
* If all argument types and name are same, return 0.
*/
int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b)
{
int i;
for (i = 0; i < a->nr_args; i++) {
if ((b->nr_args <= i) ||
((a->args[i].type != b->args[i].type) ||
(a->args[i].count != b->args[i].count) ||
strcmp(a->args[i].name, b->args[i].name)))
return i + 1;
}
return 0;
}
bool trace_probe_match_command_args(struct trace_probe *tp,
int argc, const char **argv)
{
char buf[MAX_ARGSTR_LEN + 1];
int i;
if (tp->nr_args < argc)
return false;
for (i = 0; i < argc; i++) {
snprintf(buf, sizeof(buf), "%s=%s",
tp->args[i].name, tp->args[i].comm);
if (strcmp(buf, argv[i]))
return false;
}
return true;
}

68
kernel/trace/trace_probe.h
View File

@ -89,6 +89,7 @@ enum fetch_op {
FETCH_OP_COMM, /* Current comm */
FETCH_OP_ARG, /* Function argument : .param */
FETCH_OP_FOFFS, /* File offset: .immediate */
FETCH_OP_DATA, /* Allocated data: .data */
// Stage 2 (dereference) op
FETCH_OP_DEREF, /* Dereference: .offset */
FETCH_OP_UDEREF, /* User-space Dereference: .offset */
@ -222,11 +223,18 @@ struct probe_arg {
const struct fetch_type *type; /* Type of this argument */
};
struct trace_probe {
/* Event call and class holder */
struct trace_probe_event {
unsigned int flags; /* For TP_FLAG_* */
struct trace_event_class class;
struct trace_event_call call;
struct list_head files;
struct list_head probes;
};
struct trace_probe {
struct list_head list;
struct trace_probe_event *event;
ssize_t size; /* trace entry size */
unsigned int nr_args;
struct probe_arg args[];
@ -240,19 +248,19 @@ struct event_file_link {
static inline bool trace_probe_test_flag(struct trace_probe *tp,
unsigned int flag)
{
return !!(tp->flags & flag);
return !!(tp->event->flags & flag);
}
static inline void trace_probe_set_flag(struct trace_probe *tp,
unsigned int flag)
{
tp->flags |= flag;
tp->event->flags |= flag;
}
static inline void trace_probe_clear_flag(struct trace_probe *tp,
unsigned int flag)
{
tp->flags &= ~flag;
tp->event->flags &= ~flag;
}
static inline bool trace_probe_is_enabled(struct trace_probe *tp)
@ -262,45 +270,76 @@ static inline bool trace_probe_is_enabled(struct trace_probe *tp)
static inline const char *trace_probe_name(struct trace_probe *tp)
{
return trace_event_name(&tp->call);
return trace_event_name(&tp->event->call);
}
static inline const char *trace_probe_group_name(struct trace_probe *tp)
{
return tp->call.class->system;
return tp->event->call.class->system;
}
static inline struct trace_event_call *
trace_probe_event_call(struct trace_probe *tp)
{
return &tp->call;
return &tp->event->call;
}
static inline struct trace_probe_event *
trace_probe_event_from_call(struct trace_event_call *event_call)
{
return container_of(event_call, struct trace_probe_event, call);
}
static inline struct trace_probe *
trace_probe_primary_from_call(struct trace_event_call *call)
{
struct trace_probe_event *tpe = trace_probe_event_from_call(call);
return list_first_entry(&tpe->probes, struct trace_probe, list);
}
static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp)
{
return &tp->event->probes;
}
static inline bool trace_probe_has_sibling(struct trace_probe *tp)
{
struct list_head *list = trace_probe_probe_list(tp);
return !list_empty(list) && !list_is_singular(list);
}
static inline int trace_probe_unregister_event_call(struct trace_probe *tp)
{
/* tp->event is unregistered in trace_remove_event_call() */
return trace_remove_event_call(&tp->call);
return trace_remove_event_call(&tp->event->call);
}
static inline bool trace_probe_has_single_file(struct trace_probe *tp)
{
return !!list_is_singular(&tp->files);
return !!list_is_singular(&tp->event->files);
}
int trace_probe_init(struct trace_probe *tp, const char *event,
const char *group);
void trace_probe_cleanup(struct trace_probe *tp);
int trace_probe_append(struct trace_probe *tp, struct trace_probe *to);
void trace_probe_unlink(struct trace_probe *tp);
int trace_probe_register_event_call(struct trace_probe *tp);
int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file);
int trace_probe_remove_file(struct trace_probe *tp,
struct trace_event_file *file);
struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
struct trace_event_file *file);
int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b);
bool trace_probe_match_command_args(struct trace_probe *tp,
int argc, const char **argv);
#define trace_probe_for_each_link(pos, tp) \
list_for_each_entry(pos, &(tp)->files, list)
list_for_each_entry(pos, &(tp)->event->files, list)
#define trace_probe_for_each_link_rcu(pos, tp) \
list_for_each_entry_rcu(pos, &(tp)->files, list)
list_for_each_entry_rcu(pos, &(tp)->event->files, list)
/* Check the name is good for event/group/fields */
static inline bool is_good_name(const char *name)
@ -370,6 +409,8 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
C(BAD_VAR, "Invalid $-valiable specified"), \
C(BAD_REG_NAME, "Invalid register name"), \
C(BAD_MEM_ADDR, "Invalid memory address"), \
C(BAD_IMM, "Invalid immediate value"), \
C(IMMSTR_NO_CLOSE, "String is not closed with '\"'"), \
C(FILE_ON_KPROBE, "File offset is not available with kprobe"), \
C(BAD_FILE_OFFS, "Invalid file offset value"), \
C(SYM_ON_UPROBE, "Symbol is not available with uprobe"), \
@ -393,7 +434,10 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
C(ARG_TOO_LONG, "Argument expression is too long"), \
C(NO_ARG_BODY, "No argument expression"), \
C(BAD_INSN_BNDRY, "Probe point is not an instruction boundary"),\
C(FAIL_REG_PROBE, "Failed to register probe event"),
C(FAIL_REG_PROBE, "Failed to register probe event"),\
C(DIFF_PROBE_TYPE, "Probe type is different from existing probe"),\
C(DIFF_ARG_TYPE, "Argument type or name is different from existing probe"),\
C(SAME_PROBE, "There is already the exact same probe event"),
#undef C
#define C(a, b) TP_ERR_##a

112
kernel/trace/trace_stack.c
View File

@ -53,6 +53,104 @@ static void print_max_stack(void)
}
}
/*
* The stack tracer looks for a maximum stack at each call from a function. It
* registers a callback from ftrace, and in that callback it examines the stack
* size. It determines the stack size from the variable passed in, which is the
* address of a local variable in the stack_trace_call() callback function.
* The stack size is calculated by the address of the local variable to the top
* of the current stack. If that size is smaller than the currently saved max
* stack size, nothing more is done.
*
* If the size of the stack is greater than the maximum recorded size, then the
* following algorithm takes place.
*
* For architectures (like x86) that store the function's return address before
* saving the function's local variables, the stack will look something like
* this:
*
* [ top of stack ]
* 0: sys call entry frame
* 10: return addr to entry code
* 11: start of sys_foo frame
* 20: return addr to sys_foo
* 21: start of kernel_func_bar frame
* 30: return addr to kernel_func_bar
* 31: [ do trace stack here ]
*
* The save_stack_trace() is called returning all the functions it finds in the
* current stack. Which would be (from the bottom of the stack to the top):
*
* return addr to kernel_func_bar
* return addr to sys_foo
* return addr to entry code
*
* Now to figure out how much each of these functions' local variable size is,
* a search of the stack is made to find these values. When a match is made, it
* is added to the stack_dump_trace[] array. The offset into the stack is saved
* in the stack_trace_index[] array. The above example would show:
*
* stack_dump_trace[] | stack_trace_index[]
* ------------------ + -------------------
* return addr to kernel_func_bar | 30
* return addr to sys_foo | 20
* return addr to entry | 10
*
* The print_max_stack() function above, uses these values to print the size of
* each function's portion of the stack.
*
* for (i = 0; i < nr_entries; i++) {
* size = i == nr_entries - 1 ? stack_trace_index[i] :
* stack_trace_index[i] - stack_trace_index[i+1]
* print "%d %d %d %s\n", i, stack_trace_index[i], size, stack_dump_trace[i]);
* }
*
* The above shows
*
* depth size location
* ----- ---- --------
* 0 30 10 kernel_func_bar
* 1 20 10 sys_foo
* 2 10 10 entry code
*
* Now for architectures that might save the return address after the functions
* local variables (saving the link register before calling nested functions),
* this will cause the stack to look a little different:
*
* [ top of stack ]
* 0: sys call entry frame
* 10: start of sys_foo_frame
* 19: return addr to entry code << lr saved before calling kernel_func_bar
* 20: start of kernel_func_bar frame
* 29: return addr to sys_foo_frame << lr saved before calling next function
* 30: [ do trace stack here ]
*
* Although the functions returned by save_stack_trace() may be the same, the
* placement in the stack will be different. Using the same algorithm as above
* would yield:
*
* stack_dump_trace[] | stack_trace_index[]
* ------------------ + -------------------
* return addr to kernel_func_bar | 30
* return addr to sys_foo | 29
* return addr to entry | 19
*
* Where the mapping is off by one:
*
* kernel_func_bar stack frame size is 29 - 19 not 30 - 29!
*
* To fix this, if the architecture sets ARCH_RET_ADDR_AFTER_LOCAL_VARS the
* values in stack_trace_index[] are shifted by one to and the number of
* stack trace entries is decremented by one.
*
* stack_dump_trace[] | stack_trace_index[]
* ------------------ + -------------------
* return addr to kernel_func_bar | 29
* return addr to sys_foo | 19
*
* Although the entry function is not displayed, the first function (sys_foo)
* will still include the stack size of it.
*/
static void check_stack(unsigned long ip, unsigned long *stack)
{
unsigned long this_size, flags; unsigned long *p, *top, *start;
@ -158,6 +256,20 @@ static void check_stack(unsigned long ip, unsigned long *stack)
i++;
}
#ifdef ARCH_FTRACE_SHIFT_STACK_TRACER
/*
* Some archs will store the link register before calling
* nested functions. This means the saved return address
* comes after the local storage, and we need to shift
* for that.
*/
if (x > 1) {
memmove(&stack_trace_index[0], &stack_trace_index[1],
sizeof(stack_trace_index[0]) * (x - 1));
x--;
}
#endif
stack_trace_nr_entries = x;
if (task_stack_end_corrupted(current)) {

299
kernel/trace/trace_uprobe.c
View File

@ -44,7 +44,7 @@ static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
static int trace_uprobe_release(struct dyn_event *ev);
static bool trace_uprobe_is_busy(struct dyn_event *ev);
static bool trace_uprobe_match(const char *system, const char *event,
struct dyn_event *ev);
int argc, const char **argv, struct dyn_event *ev);
static struct dyn_event_operations trace_uprobe_ops = {
.create = trace_uprobe_create,
@ -248,6 +248,9 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
case FETCH_OP_COMM:
val = FETCH_TOKEN_COMM;
break;
case FETCH_OP_DATA:
val = (unsigned long)code->data;
break;
case FETCH_OP_FOFFS:
val = translate_user_vaddr(code->immediate);
break;
@ -284,13 +287,54 @@ static bool trace_uprobe_is_busy(struct dyn_event *ev)
return trace_probe_is_enabled(&tu->tp);
}
static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
int argc, const char **argv)
{
char buf[MAX_ARGSTR_LEN + 1];
int len;
if (!argc)
return true;
len = strlen(tu->filename);
if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
return false;
if (tu->ref_ctr_offset == 0)
snprintf(buf, sizeof(buf), "0x%0*lx",
(int)(sizeof(void *) * 2), tu->offset);
else
snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
(int)(sizeof(void *) * 2), tu->offset,
tu->ref_ctr_offset);
if (strcmp(buf, &argv[0][len + 1]))
return false;
argc--; argv++;
return trace_probe_match_command_args(&tu->tp, argc, argv);
}
static bool trace_uprobe_match(const char *system, const char *event,
struct dyn_event *ev)
int argc, const char **argv, struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return strcmp(trace_probe_name(&tu->tp), event) == 0 &&
(!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0);
(!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
trace_uprobe_match_command_head(tu, argc, argv);
}
static nokprobe_inline struct trace_uprobe *
trace_uprobe_primary_from_call(struct trace_event_call *call)
{
struct trace_probe *tp;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return NULL;
return container_of(tp, struct trace_uprobe, tp);
}
/*
@ -352,15 +396,75 @@ static int unregister_trace_uprobe(struct trace_uprobe *tu)
{
int ret;
if (trace_probe_has_sibling(&tu->tp))
goto unreg;
ret = unregister_uprobe_event(tu);
if (ret)
return ret;
unreg:
dyn_event_remove(&tu->devent);
trace_probe_unlink(&tu->tp);
free_trace_uprobe(tu);
return 0;
}
static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
struct trace_uprobe *comp)
{
struct trace_probe_event *tpe = orig->tp.event;
struct trace_probe *pos;
struct inode *comp_inode = d_real_inode(comp->path.dentry);
int i;
list_for_each_entry(pos, &tpe->probes, list) {
orig = container_of(pos, struct trace_uprobe, tp);
if (comp_inode != d_real_inode(orig->path.dentry) ||
comp->offset != orig->offset)
continue;
/*
* trace_probe_compare_arg_type() ensured that nr_args and
* each argument name and type are same. Let's compare comm.
*/
for (i = 0; i < orig->tp.nr_args; i++) {
if (strcmp(orig->tp.args[i].comm,
comp->tp.args[i].comm))
continue;
}
return true;
}
return false;
}
static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
{
int ret;
ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
if (ret) {
/* Note that argument starts index = 2 */
trace_probe_log_set_index(ret + 1);
trace_probe_log_err(0, DIFF_ARG_TYPE);
return -EEXIST;
}
if (trace_uprobe_has_same_uprobe(to, tu)) {
trace_probe_log_set_index(0);
trace_probe_log_err(0, SAME_PROBE);
return -EEXIST;
}
/* Append to existing event */
ret = trace_probe_append(&tu->tp, &to->tp);
if (!ret)
dyn_event_add(&tu->devent);
return ret;
}
/*
* Uprobe with multiple reference counter is not allowed. i.e.
* If inode and offset matches, reference counter offset *must*
@ -370,25 +474,21 @@ static int unregister_trace_uprobe(struct trace_uprobe *tu)
* as the new one does not conflict with any other existing
* ones.
*/
static struct trace_uprobe *find_old_trace_uprobe(struct trace_uprobe *new)
static int validate_ref_ctr_offset(struct trace_uprobe *new)
{
struct dyn_event *pos;
struct trace_uprobe *tmp, *old = NULL;
struct trace_uprobe *tmp;
struct inode *new_inode = d_real_inode(new->path.dentry);
old = find_probe_event(trace_probe_name(&new->tp),
trace_probe_group_name(&new->tp));
for_each_trace_uprobe(tmp, pos) {
if ((old ? old != tmp : true) &&
new_inode == d_real_inode(tmp->path.dentry) &&
if (new_inode == d_real_inode(tmp->path.dentry) &&
new->offset == tmp->offset &&
new->ref_ctr_offset != tmp->ref_ctr_offset) {
pr_warn("Reference counter offset mismatch.");
return ERR_PTR(-EINVAL);
return -EINVAL;
}
}
return old;
return 0;
}
/* Register a trace_uprobe and probe_event */
@ -399,18 +499,22 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
mutex_lock(&event_mutex);
/* register as an event */
old_tu = find_old_trace_uprobe(tu);
if (IS_ERR(old_tu)) {
ret = PTR_ERR(old_tu);
ret = validate_ref_ctr_offset(tu);
if (ret)
goto end;
}
/* register as an event */
old_tu = find_probe_event(trace_probe_name(&tu->tp),
trace_probe_group_name(&tu->tp));
if (old_tu) {
/* delete old event */
ret = unregister_trace_uprobe(old_tu);
if (ret)
goto end;
if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
trace_probe_log_set_index(0);
trace_probe_log_err(0, DIFF_PROBE_TYPE);
ret = -EEXIST;
} else {
ret = append_trace_uprobe(tu, old_tu);
}
goto end;
}
ret = register_uprobe_event(tu);
@ -897,7 +1001,10 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e
u8 *data;
entry = (struct uprobe_trace_entry_head *)iter->ent;
tu = container_of(event, struct trace_uprobe, tp.call.event);
tu = trace_uprobe_primary_from_call(
container_of(event, struct trace_event_call, event));
if (unlikely(!tu))
goto out;
if (is_ret_probe(tu)) {
trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
@ -924,27 +1031,71 @@ typedef bool (*filter_func_t)(struct uprobe_consumer *self,
enum uprobe_filter_ctx ctx,
struct mm_struct *mm);
static int
probe_event_enable(struct trace_uprobe *tu, struct trace_event_file *file,
filter_func_t filter)
static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
{
bool enabled = trace_probe_is_enabled(&tu->tp);
int ret;
tu->consumer.filter = filter;
tu->inode = d_real_inode(tu->path.dentry);
if (tu->ref_ctr_offset)
ret = uprobe_register_refctr(tu->inode, tu->offset,
tu->ref_ctr_offset, &tu->consumer);
else
ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
if (ret)
tu->inode = NULL;
return ret;
}
static void __probe_event_disable(struct trace_probe *tp)
{
struct trace_probe *pos;
struct trace_uprobe *tu;
list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
tu = container_of(pos, struct trace_uprobe, tp);
if (!tu->inode)
continue;
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
tu->inode = NULL;
}
}
static int probe_event_enable(struct trace_event_call *call,
struct trace_event_file *file, filter_func_t filter)
{
struct trace_probe *pos, *tp;
struct trace_uprobe *tu;
bool enabled;
int ret;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return -ENODEV;
enabled = trace_probe_is_enabled(tp);
/* This may also change "enabled" state */
if (file) {
if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
return -EINTR;
ret = trace_probe_add_file(&tu->tp, file);
ret = trace_probe_add_file(tp, file);
if (ret < 0)
return ret;
} else {
if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
return -EINTR;
trace_probe_set_flag(&tu->tp, TP_FLAG_PROFILE);
trace_probe_set_flag(tp, TP_FLAG_PROFILE);
}
tu = container_of(tp, struct trace_uprobe, tp);
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
if (enabled)
@ -954,18 +1105,15 @@ probe_event_enable(struct trace_uprobe *tu, struct trace_event_file *file,
if (ret)
goto err_flags;
tu->consumer.filter = filter;
tu->inode = d_real_inode(tu->path.dentry);
if (tu->ref_ctr_offset) {
ret = uprobe_register_refctr(tu->inode, tu->offset,
tu->ref_ctr_offset, &tu->consumer);
} else {
ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
tu = container_of(pos, struct trace_uprobe, tp);
ret = trace_uprobe_enable(tu, filter);
if (ret) {
__probe_event_disable(tp);
goto err_buffer;
}
}
if (ret)
goto err_buffer;
return 0;
err_buffer:
@ -973,33 +1121,35 @@ probe_event_enable(struct trace_uprobe *tu, struct trace_event_file *file,
err_flags:
if (file)
trace_probe_remove_file(&tu->tp, file);
trace_probe_remove_file(tp, file);
else
trace_probe_clear_flag(&tu->tp, TP_FLAG_PROFILE);
trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
return ret;
}
static void
probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)
static void probe_event_disable(struct trace_event_call *call,
struct trace_event_file *file)
{
if (!trace_probe_is_enabled(&tu->tp))
struct trace_probe *tp;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return;
if (!trace_probe_is_enabled(tp))
return;
if (file) {
if (trace_probe_remove_file(&tu->tp, file) < 0)
if (trace_probe_remove_file(tp, file) < 0)
return;
if (trace_probe_is_enabled(&tu->tp))
if (trace_probe_is_enabled(tp))
return;
} else
trace_probe_clear_flag(&tu->tp, TP_FLAG_PROFILE);
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
tu->inode = NULL;
trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
__probe_event_disable(tp);
uprobe_buffer_disable();
}
@ -1007,7 +1157,11 @@ static int uprobe_event_define_fields(struct trace_event_call *event_call)
{
int ret, size;
struct uprobe_trace_entry_head field;
struct trace_uprobe *tu = event_call->data;
struct trace_uprobe *tu;
tu = trace_uprobe_primary_from_call(event_call);
if (unlikely(!tu))
return -ENODEV;
if (is_ret_probe(tu)) {
DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
@ -1100,6 +1254,27 @@ static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
return err;
}
static int uprobe_perf_multi_call(struct trace_event_call *call,
struct perf_event *event,
int (*op)(struct trace_uprobe *tu, struct perf_event *event))
{
struct trace_probe *pos, *tp;
struct trace_uprobe *tu;
int ret = 0;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return -ENODEV;
list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
tu = container_of(pos, struct trace_uprobe, tp);
ret = op(tu, event);
if (ret)
break;
}
return ret;
}
static bool uprobe_perf_filter(struct uprobe_consumer *uc,
enum uprobe_filter_ctx ctx, struct mm_struct *mm)
{
@ -1213,30 +1388,29 @@ static int
trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
void *data)
{
struct trace_uprobe *tu = event->data;
struct trace_event_file *file = data;
switch (type) {
case TRACE_REG_REGISTER:
return probe_event_enable(tu, file, NULL);
return probe_event_enable(event, file, NULL);
case TRACE_REG_UNREGISTER:
probe_event_disable(tu, file);
probe_event_disable(event, file);
return 0;
#ifdef CONFIG_PERF_EVENTS
case TRACE_REG_PERF_REGISTER:
return probe_event_enable(tu, NULL, uprobe_perf_filter);
return probe_event_enable(event, NULL, uprobe_perf_filter);
case TRACE_REG_PERF_UNREGISTER:
probe_event_disable(tu, NULL);
probe_event_disable(event, NULL);
return 0;
case TRACE_REG_PERF_OPEN:
return uprobe_perf_open(tu, data);
return uprobe_perf_multi_call(event, data, uprobe_perf_open);
case TRACE_REG_PERF_CLOSE:
return uprobe_perf_close(tu, data);
return uprobe_perf_multi_call(event, data, uprobe_perf_close);
#endif
default:
@ -1330,7 +1504,6 @@ static inline void init_trace_event_call(struct trace_uprobe *tu)
call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
call->class->reg = trace_uprobe_register;
call->data = tu;
}
static int register_uprobe_event(struct trace_uprobe *tu)
@ -1399,7 +1572,7 @@ void destroy_local_trace_uprobe(struct trace_event_call *event_call)
{
struct trace_uprobe *tu;
tu = container_of(event_call, struct trace_uprobe, tp.call);
tu = trace_uprobe_primary_from_call(event_call);
free_trace_uprobe(tu);
}

321
scripts/recordmcount.c
View File

@ -27,7 +27,6 @@
#include <getopt.h>
#include <elf.h>
#include <fcntl.h>
#include <setjmp.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@ -43,56 +42,37 @@ static int fd_map; /* File descriptor for file being modified. */
static int mmap_failed; /* Boolean flag. */
static char gpfx; /* prefix for global symbol name (sometimes '_') */
static struct stat sb; /* Remember .st_size, etc. */
static jmp_buf jmpenv; /* setjmp/longjmp per-file error escape */
static const char *altmcount; /* alternate mcount symbol name */
static int warn_on_notrace_sect; /* warn when section has mcount not being recorded */
static void *file_map; /* pointer of the mapped file */
static void *file_end; /* pointer to the end of the mapped file */
static int file_updated; /* flag to state file was changed */
static void *file_ptr; /* current file pointer location */
static void *file_append; /* added to the end of the file */
static size_t file_append_size; /* how much is added to end of file */
/* setjmp() return values */
enum {
SJ_SETJMP = 0, /* hardwired first return */
SJ_FAIL,
SJ_SUCCEED
};
/* Per-file resource cleanup when multiple files. */
static void
cleanup(void)
static void file_append_cleanup(void)
{
if (!mmap_failed)
munmap(file_map, sb.st_size);
else
free(file_map);
file_map = NULL;
free(file_append);
file_append = NULL;
file_append_size = 0;
file_updated = 0;
}
static void __attribute__((noreturn))
fail_file(void)
static void mmap_cleanup(void)
{
cleanup();
longjmp(jmpenv, SJ_FAIL);
if (!mmap_failed)
munmap(file_map, sb.st_size);
else
free(file_map);
file_map = NULL;
}
static void __attribute__((noreturn))
succeed_file(void)
{
cleanup();
longjmp(jmpenv, SJ_SUCCEED);
}
/* ulseek, uwrite, ...: Check return value for errors. */
/* ulseek, uread, ...: Check return value for errors. */
static off_t
ulseek(int const fd, off_t const offset, int const whence)
static off_t ulseek(off_t const offset, int const whence)
{
switch (whence) {
case SEEK_SET:
@ -107,24 +87,12 @@ ulseek(int const fd, off_t const offset, int const whence)
}
if (file_ptr < file_map) {
fprintf(stderr, "lseek: seek before file\n");
fail_file();
return -1;
}
return file_ptr - file_map;
}
static size_t
uread(int const fd, void *const buf, size_t const count)
{
size_t const n = read(fd, buf, count);
if (n != count) {
perror("read");
fail_file();
}
return n;
}
static size_t
uwrite(int const fd, void const *const buf, size_t const count)
static ssize_t uwrite(void const *const buf, size_t const count)
{
size_t cnt = count;
off_t idx = 0;
@ -140,7 +108,9 @@ uwrite(int const fd, void const *const buf, size_t const count)
}
if (!file_append) {
perror("write");
fail_file();
file_append_cleanup();
mmap_cleanup();
return -1;
}
if (file_ptr < file_end) {
cnt = file_end - file_ptr;
@ -160,17 +130,81 @@ uwrite(int const fd, void const *const buf, size_t const count)
return count;
}
static void *
umalloc(size_t size)
static void * umalloc(size_t size)
{
void *const addr = malloc(size);
if (addr == 0) {
fprintf(stderr, "malloc failed: %zu bytes\n", size);
fail_file();
file_append_cleanup();
mmap_cleanup();
return NULL;
}
return addr;
}
/*
* Get the whole file as a programming convenience in order to avoid
* malloc+lseek+read+free of many pieces. If successful, then mmap
* avoids copying unused pieces; else just read the whole file.
* Open for both read and write; new info will be appended to the file.
* Use MAP_PRIVATE so that a few changes to the in-memory ElfXX_Ehdr
* do not propagate to the file until an explicit overwrite at the last.
* This preserves most aspects of consistency (all except .st_size)
* for simultaneous readers of the file while we are appending to it.
* However, multiple writers still are bad. We choose not to use
* locking because it is expensive and the use case of kernel build
* makes multiple writers unlikely.
*/
static void *mmap_file(char const *fname)
{
/* Avoid problems if early cleanup() */
fd_map = -1;
mmap_failed = 1;
file_map = NULL;
file_ptr = NULL;
file_updated = 0;
sb.st_size = 0;
fd_map = open(fname, O_RDONLY);
if (fd_map < 0) {
perror(fname);
return NULL;
}
if (fstat(fd_map, &sb) < 0) {
perror(fname);
goto out;
}
if (!S_ISREG(sb.st_mode)) {
fprintf(stderr, "not a regular file: %s\n", fname);
goto out;
}
file_map = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
fd_map, 0);
if (file_map == MAP_FAILED) {
mmap_failed = 1;
file_map = umalloc(sb.st_size);
if (!file_map) {
perror(fname);
goto out;
}
if (read(fd_map, file_map, sb.st_size) != sb.st_size) {
perror(fname);
free(file_map);
file_map = NULL;
goto out;
}
} else
mmap_failed = 0;
out:
close(fd_map);
fd_map = -1;
file_end = file_map + sb.st_size;
return file_map;
}
static unsigned char ideal_nop5_x86_64[5] = { 0x0f, 0x1f, 0x44, 0x00, 0x00 };
static unsigned char ideal_nop5_x86_32[5] = { 0x3e, 0x8d, 0x74, 0x26, 0x00 };
static unsigned char *ideal_nop;
@ -194,8 +228,10 @@ static int make_nop_x86(void *map, size_t const offset)
return -1;
/* convert to nop */
ulseek(fd_map, offset - 1, SEEK_SET);
uwrite(fd_map, ideal_nop, 5);
if (ulseek(offset - 1, SEEK_SET) < 0)
return -1;
if (uwrite(ideal_nop, 5) < 0)
return -1;
return 0;
}
@ -243,10 +279,12 @@ static int make_nop_arm(void *map, size_t const offset)
return -1;
/* Convert to nop */
ulseek(fd_map, off, SEEK_SET);
if (ulseek(off, SEEK_SET) < 0)
return -1;
do {
uwrite(fd_map, ideal_nop, nop_size);
if (uwrite(ideal_nop, nop_size) < 0)
return -1;
} while (--cnt > 0);
return 0;
@ -263,57 +301,20 @@ static int make_nop_arm64(void *map, size_t const offset)
return -1;
/* Convert to nop */
ulseek(fd_map, offset, SEEK_SET);
uwrite(fd_map, ideal_nop, 4);
if (ulseek(offset, SEEK_SET) < 0)
return -1;
if (uwrite(ideal_nop, 4) < 0)
return -1;
return 0;
}
/*
* Get the whole file as a programming convenience in order to avoid
* malloc+lseek+read+free of many pieces. If successful, then mmap
* avoids copying unused pieces; else just read the whole file.
* Open for both read and write; new info will be appended to the file.
* Use MAP_PRIVATE so that a few changes to the in-memory ElfXX_Ehdr
* do not propagate to the file until an explicit overwrite at the last.
* This preserves most aspects of consistency (all except .st_size)
* for simultaneous readers of the file while we are appending to it.
* However, multiple writers still are bad. We choose not to use
* locking because it is expensive and the use case of kernel build
* makes multiple writers unlikely.
*/
static void *mmap_file(char const *fname)
{
fd_map = open(fname, O_RDONLY);
if (fd_map < 0 || fstat(fd_map, &sb) < 0) {
perror(fname);
fail_file();
}
if (!S_ISREG(sb.st_mode)) {
fprintf(stderr, "not a regular file: %s\n", fname);
fail_file();
}
file_map = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
fd_map, 0);
mmap_failed = 0;
if (file_map == MAP_FAILED) {
mmap_failed = 1;
file_map = umalloc(sb.st_size);
uread(fd_map, file_map, sb.st_size);
}
close(fd_map);
file_end = file_map + sb.st_size;
return file_map;
}
static void write_file(const char *fname)
static int write_file(const char *fname)
{
char tmp_file[strlen(fname) + 4];
size_t n;
if (!file_updated)
return;
return 0;
sprintf(tmp_file, "%s.rc", fname);
@ -325,25 +326,28 @@ static void write_file(const char *fname)
fd_map = open(tmp_file, O_WRONLY | O_TRUNC | O_CREAT, sb.st_mode);
if (fd_map < 0) {
perror(fname);
fail_file();
return -1;
}
n = write(fd_map, file_map, sb.st_size);
if (n != sb.st_size) {
perror("write");
fail_file();
close(fd_map);
return -1;
}
if (file_append_size) {
n = write(fd_map, file_append, file_append_size);
if (n != file_append_size) {
perror("write");
fail_file();
close(fd_map);
return -1;
}
}
close(fd_map);
if (rename(tmp_file, fname) < 0) {
perror(fname);
fail_file();
return -1;
}
return 0;
}
/* w8rev, w8nat, ...: Handle endianness. */
@ -394,8 +398,7 @@ static uint32_t (*w)(uint32_t);
static uint32_t (*w2)(uint16_t);
/* Names of the sections that could contain calls to mcount. */
static int
is_mcounted_section_name(char const *const txtname)
static int is_mcounted_section_name(char const *const txtname)
{
return strncmp(".text", txtname, 5) == 0 ||
strcmp(".init.text", txtname) == 0 ||
@ -405,10 +408,11 @@ is_mcounted_section_name(char const *const txtname)
strcmp(".irqentry.text", txtname) == 0 ||
strcmp(".softirqentry.text", txtname) == 0 ||
strcmp(".kprobes.text", txtname) == 0 ||
strcmp(".cpuidle.text", txtname) == 0 ||
strcmp(".text.unlikely", txtname) == 0;
strcmp(".cpuidle.text", txtname) == 0;
}
static char const *already_has_rel_mcount = "success"; /* our work here is done! */
/* 32 bit and 64 bit are very similar */
#include "recordmcount.h"
#define RECORD_MCOUNT_64
@ -447,11 +451,15 @@ static void MIPS64_r_info(Elf64_Rel *const rp, unsigned sym, unsigned type)
}).r_info;
}
static void
do_file(char const *const fname)
static int do_file(char const *const fname)
{
Elf32_Ehdr *const ehdr = mmap_file(fname);
unsigned int reltype = 0;
Elf32_Ehdr *ehdr;
int rc = -1;
ehdr = mmap_file(fname);
if (!ehdr)
goto out;
w = w4nat;
w2 = w2nat;
@ -461,8 +469,7 @@ do_file(char const *const fname)
default:
fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
ehdr->e_ident[EI_DATA], fname);
fail_file();
break;
goto out;
case ELFDATA2LSB:
if (*(unsigned char const *)&endian != 1) {
/* main() is big endian, file.o is little endian. */
@ -490,52 +497,54 @@ do_file(char const *const fname)
push_bl_mcount_thumb = push_bl_mcount_thumb_be;
break;
} /* end switch */
if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
|| w2(ehdr->e_type) != ET_REL
|| ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0 ||
w2(ehdr->e_type) != ET_REL ||
ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
fprintf(stderr, "unrecognized ET_REL file %s\n", fname);
fail_file();
goto out;
}
gpfx = 0;
gpfx = '_';
switch (w2(ehdr->e_machine)) {
default:
fprintf(stderr, "unrecognized e_machine %u %s\n",
w2(ehdr->e_machine), fname);
fail_file();
break;
goto out;
case EM_386:
reltype = R_386_32;
rel_type_nop = R_386_NONE;
make_nop = make_nop_x86;
ideal_nop = ideal_nop5_x86_32;
mcount_adjust_32 = -1;
gpfx = 0;
break;
case EM_ARM:
reltype = R_ARM_ABS32;
altmcount = "__gnu_mcount_nc";
make_nop = make_nop_arm;
rel_type_nop = R_ARM_NONE;
gpfx = 0;
break;
case EM_ARM: reltype = R_ARM_ABS32;
altmcount = "__gnu_mcount_nc";
make_nop = make_nop_arm;
rel_type_nop = R_ARM_NONE;
break;
case EM_AARCH64:
reltype = R_AARCH64_ABS64;
make_nop = make_nop_arm64;
rel_type_nop = R_AARCH64_NONE;
ideal_nop = ideal_nop4_arm64;
gpfx = '_';
break;
case EM_IA_64: reltype = R_IA64_IMM64; gpfx = '_'; break;
case EM_MIPS: /* reltype: e_class */ gpfx = '_'; break;
case EM_PPC: reltype = R_PPC_ADDR32; gpfx = '_'; break;
case EM_PPC64: reltype = R_PPC64_ADDR64; gpfx = '_'; break;
case EM_S390: /* reltype: e_class */ gpfx = '_'; break;
case EM_SH: reltype = R_SH_DIR32; break;
case EM_SPARCV9: reltype = R_SPARC_64; gpfx = '_'; break;
reltype = R_AARCH64_ABS64;
make_nop = make_nop_arm64;
rel_type_nop = R_AARCH64_NONE;
ideal_nop = ideal_nop4_arm64;
break;
case EM_IA_64: reltype = R_IA64_IMM64; break;
case EM_MIPS: /* reltype: e_class */ break;
case EM_PPC: reltype = R_PPC_ADDR32; break;
case EM_PPC64: reltype = R_PPC64_ADDR64; break;
case EM_S390: /* reltype: e_class */ break;
case EM_SH: reltype = R_SH_DIR32; gpfx = 0; break;
case EM_SPARCV9: reltype = R_SPARC_64; break;
case EM_X86_64:
make_nop = make_nop_x86;
ideal_nop = ideal_nop5_x86_64;
reltype = R_X86_64_64;
rel_type_nop = R_X86_64_NONE;
mcount_adjust_64 = -1;
gpfx = 0;
break;
} /* end switch */
@ -543,20 +552,20 @@ do_file(char const *const fname)
default:
fprintf(stderr, "unrecognized ELF class %d %s\n",
ehdr->e_ident[EI_CLASS], fname);
fail_file();
break;
goto out;
case ELFCLASS32:
if (w2(ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
|| w2(ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
fprintf(stderr,
"unrecognized ET_REL file: %s\n", fname);
fail_file();
goto out;
}
if (w2(ehdr->e_machine) == EM_MIPS) {
reltype = R_MIPS_32;
is_fake_mcount32 = MIPS32_is_fake_mcount;
}
do32(ehdr, fname, reltype);
if (do32(ehdr, fname, reltype) < 0)
goto out;
break;
case ELFCLASS64: {
Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
@ -564,7 +573,7 @@ do_file(char const *const fname)
|| w2(ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
fprintf(stderr,
"unrecognized ET_REL file: %s\n", fname);
fail_file();
goto out;
}
if (w2(ghdr->e_machine) == EM_S390) {
reltype = R_390_64;
@ -576,17 +585,20 @@ do_file(char const *const fname)
Elf64_r_info = MIPS64_r_info;
is_fake_mcount64 = MIPS64_is_fake_mcount;
}
do64(ghdr, fname, reltype);
if (do64(ghdr, fname, reltype) < 0)
goto out;
break;
}
} /* end switch */
write_file(fname);
cleanup();
rc = write_file(fname);
out:
file_append_cleanup();
mmap_cleanup();
return rc;
}
int
main(int argc, char *argv[])
int main(int argc, char *argv[])
{
const char ftrace[] = "/ftrace.o";
int ftrace_size = sizeof(ftrace) - 1;
@ -613,7 +625,6 @@ main(int argc, char *argv[])
/* Process each file in turn, allowing deep failure. */
for (i = optind; i < argc; i++) {
char *file = argv[i];
int const sjval = setjmp(jmpenv);
int len;
/*
@ -626,28 +637,10 @@ main(int argc, char *argv[])
strcmp(file + (len - ftrace_size), ftrace) == 0)
continue;
switch (sjval) {
default:
fprintf(stderr, "internal error: %s\n", file);
exit(1);
break;
case SJ_SETJMP: /* normal sequence */
/* Avoid problems if early cleanup() */
fd_map = -1;
mmap_failed = 1;
file_map = NULL;
file_ptr = NULL;
file_updated = 0;
do_file(file);
break;
case SJ_FAIL: /* error in do_file or below */
if (do_file(file)) {
fprintf(stderr, "%s: failed\n", file);
++n_error;
break;
case SJ_SUCCEED: /* premature success */
/* do nothing */
break;
} /* end switch */
}
}
return !!n_error;
}

150
scripts/recordmcount.h
View File

@ -174,7 +174,7 @@ static int MIPS_is_fake_mcount(Elf_Rel const *rp)
}
/* Append the new shstrtab, Elf_Shdr[], __mcount_loc and its relocations. */
static void append_func(Elf_Ehdr *const ehdr,
static int append_func(Elf_Ehdr *const ehdr,
Elf_Shdr *const shstr,
uint_t const *const mloc0,
uint_t const *const mlocp,
@ -202,15 +202,20 @@ static void append_func(Elf_Ehdr *const ehdr,
new_e_shoff = t;
/* body for new shstrtab */
ulseek(fd_map, sb.st_size, SEEK_SET);
uwrite(fd_map, old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size);
uwrite(fd_map, mc_name, 1 + strlen(mc_name));
if (ulseek(sb.st_size, SEEK_SET) < 0)
return -1;
if (uwrite(old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size) < 0)
return -1;
if (uwrite(mc_name, 1 + strlen(mc_name)) < 0)
return -1;
/* old(modified) Elf_Shdr table, word-byte aligned */
ulseek(fd_map, t, SEEK_SET);
if (ulseek(t, SEEK_SET) < 0)
return -1;
t += sizeof(Elf_Shdr) * old_shnum;
uwrite(fd_map, old_shoff + (void *)ehdr,
sizeof(Elf_Shdr) * old_shnum);
if (uwrite(old_shoff + (void *)ehdr,
sizeof(Elf_Shdr) * old_shnum) < 0)
return -1;
/* new sections __mcount_loc and .rel__mcount_loc */
t += 2*sizeof(mcsec);
@ -225,7 +230,8 @@ static void append_func(Elf_Ehdr *const ehdr,
mcsec.sh_info = 0;
mcsec.sh_addralign = _w(_size);
mcsec.sh_entsize = _w(_size);
uwrite(fd_map, &mcsec, sizeof(mcsec));
if (uwrite(&mcsec, sizeof(mcsec)) < 0)
return -1;
mcsec.sh_name = w(old_shstr_sh_size);
mcsec.sh_type = (sizeof(Elf_Rela) == rel_entsize)
@ -239,15 +245,22 @@ static void append_func(Elf_Ehdr *const ehdr,
mcsec.sh_info = w(old_shnum);
mcsec.sh_addralign = _w(_size);
mcsec.sh_entsize = _w(rel_entsize);
uwrite(fd_map, &mcsec, sizeof(mcsec));
uwrite(fd_map, mloc0, (void *)mlocp - (void *)mloc0);
uwrite(fd_map, mrel0, (void *)mrelp - (void *)mrel0);
if (uwrite(&mcsec, sizeof(mcsec)) < 0)
return -1;
if (uwrite(mloc0, (void *)mlocp - (void *)mloc0) < 0)
return -1;
if (uwrite(mrel0, (void *)mrelp - (void *)mrel0) < 0)
return -1;
ehdr->e_shoff = _w(new_e_shoff);
ehdr->e_shnum = w2(2 + w2(ehdr->e_shnum)); /* {.rel,}__mcount_loc */
ulseek(fd_map, 0, SEEK_SET);
uwrite(fd_map, ehdr, sizeof(*ehdr));
if (ulseek(0, SEEK_SET) < 0)
return -1;
if (uwrite(ehdr, sizeof(*ehdr)) < 0)
return -1;
return 0;
}
static unsigned get_mcountsym(Elf_Sym const *const sym0,
@ -351,9 +364,9 @@ static uint_t *sift_rel_mcount(uint_t *mlocp,
* that are not going to be traced. The mcount calls here will be converted
* into nops.
*/
static void nop_mcount(Elf_Shdr const *const relhdr,
Elf_Ehdr const *const ehdr,
const char *const txtname)
static int nop_mcount(Elf_Shdr const *const relhdr,
Elf_Ehdr const *const ehdr,
const char *const txtname)
{
Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
+ (void *)ehdr);
@ -376,15 +389,18 @@ static void nop_mcount(Elf_Shdr const *const relhdr,
mcountsym = get_mcountsym(sym0, relp, str0);
if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) {
if (make_nop)
if (make_nop) {
ret = make_nop((void *)ehdr, _w(shdr->sh_offset) + _w(relp->r_offset));
if (ret < 0)
return -1;
}
if (warn_on_notrace_sect && !once) {
printf("Section %s has mcount callers being ignored\n",
txtname);
once = 1;
/* just warn? */
if (!make_nop)
return;
return 0;
}
}
@ -396,14 +412,16 @@ static void nop_mcount(Elf_Shdr const *const relhdr,
Elf_Rel rel;
rel = *(Elf_Rel *)relp;
Elf_r_info(&rel, Elf_r_sym(relp), rel_type_nop);
ulseek(fd_map, (void *)relp - (void *)ehdr, SEEK_SET);
uwrite(fd_map, &rel, sizeof(rel));
if (ulseek((void *)relp - (void *)ehdr, SEEK_SET) < 0)
return -1;
if (uwrite(&rel, sizeof(rel)) < 0)
return -1;
}
relp = (Elf_Rel const *)(rel_entsize + (void *)relp);
}
return 0;
}
/*
* Find a symbol in the given section, to be used as the base for relocating
* the table of offsets of calls to mcount. A local or global symbol suffices,
@ -414,9 +432,10 @@ static void nop_mcount(Elf_Shdr const *const relhdr,
* Num: Value Size Type Bind Vis Ndx Name
* 2: 00000000 0 SECTION LOCAL DEFAULT 1
*/
static unsigned find_secsym_ndx(unsigned const txtndx,
static int find_secsym_ndx(unsigned const txtndx,
char const *const txtname,
uint_t *const recvalp,
unsigned int *sym_index,
Elf_Shdr const *const symhdr,
Elf_Ehdr const *const ehdr)
{
@ -438,21 +457,20 @@ static unsigned find_secsym_ndx(unsigned const txtndx,
continue;
*recvalp = _w(symp->st_value);
return symp - sym0;
*sym_index = symp - sym0;
return 0;
}
}
fprintf(stderr, "Cannot find symbol for section %u: %s.\n",
txtndx, txtname);
fail_file();
return -1;
}
/* Evade ISO C restriction: no declaration after statement in has_rel_mcount. */
static char const *
__has_rel_mcount(Elf_Shdr const *const relhdr, /* is SHT_REL or SHT_RELA */
Elf_Shdr const *const shdr0,
char const *const shstrtab,
char const *const fname)
static char const * __has_rel_mcount(Elf_Shdr const *const relhdr, /* reltype */
Elf_Shdr const *const shdr0,
char const *const shstrtab,
char const *const fname)
{
/* .sh_info depends on .sh_type == SHT_REL[,A] */
Elf_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)];
@ -461,7 +479,7 @@ __has_rel_mcount(Elf_Shdr const *const relhdr, /* is SHT_REL or SHT_RELA */
if (strcmp("__mcount_loc", txtname) == 0) {
fprintf(stderr, "warning: __mcount_loc already exists: %s\n",
fname);
succeed_file();
return already_has_rel_mcount;
}
if (w(txthdr->sh_type) != SHT_PROGBITS ||
!(_w(txthdr->sh_flags) & SHF_EXECINSTR))
@ -491,6 +509,10 @@ static unsigned tot_relsize(Elf_Shdr const *const shdr0,
for (; nhdr; --nhdr, ++shdrp) {
txtname = has_rel_mcount(shdrp, shdr0, shstrtab, fname);
if (txtname == already_has_rel_mcount) {
totrelsz = 0;
break;
}
if (txtname && is_mcounted_section_name(txtname))
totrelsz += _w(shdrp->sh_size);
}
@ -499,8 +521,8 @@ static unsigned tot_relsize(Elf_Shdr const *const shdr0,
/* Overall supervision for Elf32 ET_REL file. */
static void
do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
static int do_func(Elf_Ehdr *const ehdr, char const *const fname,
unsigned const reltype)
{
Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
+ (void *)ehdr);
@ -513,26 +535,54 @@ do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
unsigned k;
/* Upper bound on space: assume all relevant relocs are for mcount. */
unsigned const totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname);
Elf_Rel *const mrel0 = umalloc(totrelsz);
Elf_Rel * mrelp = mrel0;
unsigned totrelsz;
/* 2*sizeof(address) <= sizeof(Elf_Rel) */
uint_t *const mloc0 = umalloc(totrelsz>>1);
uint_t * mlocp = mloc0;
Elf_Rel * mrel0;
Elf_Rel * mrelp;
uint_t * mloc0;
uint_t * mlocp;
unsigned rel_entsize = 0;
unsigned symsec_sh_link = 0;
int result = 0;
totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname);
if (totrelsz == 0)
return 0;
mrel0 = umalloc(totrelsz);
mrelp = mrel0;
if (!mrel0)
return -1;
/* 2*sizeof(address) <= sizeof(Elf_Rel) */
mloc0 = umalloc(totrelsz>>1);
mlocp = mloc0;
if (!mloc0) {
free(mrel0);
return -1;
}
for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) {
char const *const txtname = has_rel_mcount(relhdr, shdr0,
shstrtab, fname);
if (txtname == already_has_rel_mcount) {
result = 0;
file_updated = 0;
goto out; /* Nothing to be done; don't append! */
}
if (txtname && is_mcounted_section_name(txtname)) {
unsigned int recsym;
uint_t recval = 0;
unsigned const recsym = find_secsym_ndx(
w(relhdr->sh_info), txtname, &recval,
&shdr0[symsec_sh_link = w(relhdr->sh_link)],
ehdr);
symsec_sh_link = w(relhdr->sh_link);
result = find_secsym_ndx(w(relhdr->sh_info), txtname,
&recval, &recsym,
&shdr0[symsec_sh_link],
ehdr);
if (result)
goto out;
rel_entsize = _w(relhdr->sh_entsize);
mlocp = sift_rel_mcount(mlocp,
@ -543,13 +593,17 @@ do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
* This section is ignored by ftrace, but still
* has mcount calls. Convert them to nops now.
*/
nop_mcount(relhdr, ehdr, txtname);
if (nop_mcount(relhdr, ehdr, txtname) < 0) {
result = -1;
goto out;
}
}
}
if (mloc0 != mlocp) {
append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp,
rel_entsize, symsec_sh_link);
}
if (!result && mloc0 != mlocp)
result = append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp,
rel_entsize, symsec_sh_link);
out:
free(mrel0);
free(mloc0);
return result;
}

2
tools/testing/selftests/ftrace/test.d/functions
View File

@ -115,7 +115,7 @@ ftrace_errlog_check() { # err-prefix command-with-error-pos-by-^ command-file
command=$(echo "$2" | tr -d ^)
echo "Test command: $command"
echo > error_log
(! echo "$command" > "$3" ) 2> /dev/null
(! echo "$command" >> "$3" ) 2> /dev/null
grep "$1: error:" -A 3 error_log
N=$(tail -n 1 error_log | wc -c)
# " Command: " and "^\n" => 13

16
tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
View File

@ -24,7 +24,21 @@ test -d events/kprobes2/event2 || exit_failure
:;: "Add an event on dot function without name" ;:
FUNC=`grep -m 10 " [tT] .*\.isra\..*$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "`
find_dot_func() {
if [ ! -f available_filter_functions ]; then
grep -m 10 " [tT] .*\.isra\..*$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "
return;
fi
grep " [tT] .*\.isra\..*" /proc/kallsyms | cut -f 3 -d " " | while read f; do
if grep -s $f available_filter_functions; then
echo $f
break
fi
done
}
FUNC=`find_dot_func | tail -n 1`
[ "x" != "x$FUNC" ] || exit_unresolved
echo "p $FUNC" > kprobe_events
EVENT=`grep $FUNC kprobe_events | cut -f 1 -d " " | cut -f 2 -d:`

35
tools/testing/selftests/ftrace/test.d/kprobe/kprobe_multiprobe.tc Normal file
View File

@ -0,0 +1,35 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# description: Create/delete multiprobe on kprobe event
[ -f kprobe_events ] || exit_unsupported
grep -q "Create/append/" README || exit_unsupported
# Choose 2 symbols for target
SYM1=_do_fork
SYM2=do_exit
EVENT_NAME=kprobes/testevent
DEF1="p:$EVENT_NAME $SYM1"
DEF2="p:$EVENT_NAME $SYM2"
:;: "Define an event which has 2 probes" ;:
echo $DEF1 >> kprobe_events
echo $DEF2 >> kprobe_events
cat kprobe_events | grep "$DEF1"
cat kprobe_events | grep "$DEF2"
:;: "Remove the event by name (should remove both)" ;:
echo "-:$EVENT_NAME" >> kprobe_events
test `cat kprobe_events | wc -l` -eq 0
:;: "Remove just 1 event" ;:
echo $DEF1 >> kprobe_events
echo $DEF2 >> kprobe_events
echo "-:$EVENT_NAME $SYM1" >> kprobe_events
! cat kprobe_events | grep "$DEF1"
cat kprobe_events | grep "$DEF2"
:;: "Appending different type must fail" ;:
! echo "$DEF1 \$stack" >> kprobe_events

16
tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc
View File

@ -41,6 +41,11 @@ check_error 'p vfs_read ^%none_reg' # BAD_REG_NAME
check_error 'p vfs_read ^@12345678abcde' # BAD_MEM_ADDR
check_error 'p vfs_read ^@+10' # FILE_ON_KPROBE
grep -q "imm-value" README && \
check_error 'p vfs_read arg1=\^x' # BAD_IMM
grep -q "imm-string" README && \
check_error 'p vfs_read arg1=\"abcd^' # IMMSTR_NO_CLOSE
check_error 'p vfs_read ^+0@0)' # DEREF_NEED_BRACE
check_error 'p vfs_read ^+0ab1(@0)' # BAD_DEREF_OFFS
check_error 'p vfs_read +0(+0(@0^)' # DEREF_OPEN_BRACE
@ -82,4 +87,15 @@ case $(uname -m) in
;;
esac
# multiprobe errors
if grep -q "Create/append/" README && grep -q "imm-value" README; then
echo 'p:kprobes/testevent _do_fork' > kprobe_events
check_error '^r:kprobes/testevent do_exit' # DIFF_PROBE_TYPE
echo 'p:kprobes/testevent _do_fork abcd=\1' > kprobe_events
check_error 'p:kprobes/testevent _do_fork ^bcd=\1' # DIFF_ARG_TYPE
check_error 'p:kprobes/testevent _do_fork ^abcd=\1:u8' # DIFF_ARG_TYPE
check_error 'p:kprobes/testevent _do_fork ^abcd=\"foo"' # DIFF_ARG_TYPE
check_error '^p:kprobes/testevent _do_fork' # SAME_PROBE
fi
exit 0