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kernel/trace: Provide default impelentations defined in trace_probe_tmpl.h

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There are 6 function definitions in trace_probe_tmpl.h, they are:

1, fetch_store_strlen
2, fetch_store_string
3, fetch_store_strlen_user
4, fetch_store_string_user
5, probe_mem_read
6, probe_mem_read_user

Every C file which includes trace_probe_tmpl.h has to implement them,
otherwise it gets warnings and errors. However, some of them are identical,
like kprobe and eprobe, as a result, there is a lot redundant code in those
2 files.

This patch would like to provide default behaviors for those functions
which kprobe and eprobe can share by just including trace_probe_kernel.h
with trace_probe_tmpl.h together.

It removes redundant code, increases readability, and more importantly,
makes it easier to introduce a new feature based on trace probe
(it's possible).

Link: https://lore.kernel.org/all/1672382018-18347-1-git-send-email-chensong_2000@189.cn/

Signed-off-by: Song Chen <chensong_2000@189.cn>
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
This commit is contained in:
Song Chen 2022-12-30 14:33:38 +08:00 committed by Masami Hiramatsu (Google)
parent 196b6389a3
commit 672a2bf840
4 changed files with 29 additions and 116 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

55
kernel/trace/trace_eprobe.c
View File

@ -320,7 +320,8 @@ print_eprobe_event(struct trace_iterator *iter, int flags,
return trace_handle_return(s);
}
static unsigned long get_event_field(struct fetch_insn *code, void *rec)
static nokprobe_inline unsigned long
get_event_field(struct fetch_insn *code, void *rec)
{
struct ftrace_event_field *field = code->data;
unsigned long val;
@ -454,58 +455,6 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
}
NOKPROBE_SYMBOL(process_fetch_insn)
/* Return the length of string -- including null terminal byte */
static nokprobe_inline int
fetch_store_strlen_user(unsigned long addr)
{
return kern_fetch_store_strlen_user(addr);
}
/* Return the length of string -- including null terminal byte */
static nokprobe_inline int
fetch_store_strlen(unsigned long addr)
{
return kern_fetch_store_strlen(addr);
}
/*
* Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
* with max length and relative data location.
*/
static nokprobe_inline int
fetch_store_string_user(unsigned long addr, void *dest, void *base)
{
return kern_fetch_store_string_user(addr, dest, base);
}
/*
* Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
* length and relative data location.
*/
static nokprobe_inline int
fetch_store_string(unsigned long addr, void *dest, void *base)
{
return kern_fetch_store_string(addr, dest, base);
}
static nokprobe_inline int
probe_mem_read_user(void *dest, void *src, size_t size)
{
const void __user *uaddr = (__force const void __user *)src;
return copy_from_user_nofault(dest, uaddr, size);
}
static nokprobe_inline int
probe_mem_read(void *dest, void *src, size_t size)
{
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
if ((unsigned long)src < TASK_SIZE)
return probe_mem_read_user(dest, src, size);
#endif
return copy_from_kernel_nofault(dest, src, size);
}
/* eprobe handler */
static inline void
__eprobe_trace_func(struct eprobe_data *edata, void *rec)

6
kernel/trace/trace_events_synth.c
View File

@ -420,12 +420,12 @@ static unsigned int trace_string(struct synth_trace_event *entry,
data_offset += event->n_u64 * sizeof(u64);
data_offset += data_size;
len = kern_fetch_store_strlen((unsigned long)str_val);
len = fetch_store_strlen((unsigned long)str_val);
data_offset |= len << 16;
*(u32 *)&entry->fields[*n_u64] = data_offset;
ret = kern_fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry);
ret = fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry);
(*n_u64)++;
} else {
@ -473,7 +473,7 @@ static notrace void trace_event_raw_event_synth(void *__data,
val_idx = var_ref_idx[field_pos];
str_val = (char *)(long)var_ref_vals[val_idx];
len = kern_fetch_store_strlen((unsigned long)str_val);
len = fetch_store_strlen((unsigned long)str_val);
fields_size += len;
}

54
kernel/trace/trace_kprobe.c
View File

@ -1218,60 +1218,6 @@ static const struct file_operations kprobe_profile_ops = {
.release = seq_release,
};
/* Kprobe specific fetch functions */
/* Return the length of string -- including null terminal byte */
static nokprobe_inline int
fetch_store_strlen_user(unsigned long addr)
{
return kern_fetch_store_strlen_user(addr);
}
/* Return the length of string -- including null terminal byte */
static nokprobe_inline int
fetch_store_strlen(unsigned long addr)
{
return kern_fetch_store_strlen(addr);
}
/*
* Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
* with max length and relative data location.
*/
static nokprobe_inline int
fetch_store_string_user(unsigned long addr, void *dest, void *base)
{
return kern_fetch_store_string_user(addr, dest, base);
}
/*
* Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
* length and relative data location.
*/
static nokprobe_inline int
fetch_store_string(unsigned long addr, void *dest, void *base)
{
return kern_fetch_store_string(addr, dest, base);
}
static nokprobe_inline int
probe_mem_read_user(void *dest, void *src, size_t size)
{
const void __user *uaddr = (__force const void __user *)src;
return copy_from_user_nofault(dest, uaddr, size);
}
static nokprobe_inline int
probe_mem_read(void *dest, void *src, size_t size)
{
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
if ((unsigned long)src < TASK_SIZE)
return probe_mem_read_user(dest, src, size);
#endif
return copy_from_kernel_nofault(dest, src, size);
}
/* Note that we don't verify it, since the code does not come from user space */
static int
process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,

30
kernel/trace/trace_probe_kernel.h
View File

@ -12,7 +12,7 @@
*/
/* Return the length of string -- including null terminal byte */
static nokprobe_inline int
kern_fetch_store_strlen_user(unsigned long addr)
fetch_store_strlen_user(unsigned long addr)
{
const void __user *uaddr = (__force const void __user *)addr;
int ret;
@ -29,14 +29,14 @@ kern_fetch_store_strlen_user(unsigned long addr)
/* Return the length of string -- including null terminal byte */
static nokprobe_inline int
kern_fetch_store_strlen(unsigned long addr)
fetch_store_strlen(unsigned long addr)
{
int ret, len = 0;
u8 c;
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
if (addr < TASK_SIZE)
return kern_fetch_store_strlen_user(addr);
return fetch_store_strlen_user(addr);
#endif
do {
@ -63,7 +63,7 @@ static nokprobe_inline void set_data_loc(int ret, void *dest, void *__dest, void
* with max length and relative data location.
*/
static nokprobe_inline int
kern_fetch_store_string_user(unsigned long addr, void *dest, void *base)
fetch_store_string_user(unsigned long addr, void *dest, void *base)
{
const void __user *uaddr = (__force const void __user *)addr;
int maxlen = get_loc_len(*(u32 *)dest);
@ -86,7 +86,7 @@ kern_fetch_store_string_user(unsigned long addr, void *dest, void *base)
* length and relative data location.
*/
static nokprobe_inline int
kern_fetch_store_string(unsigned long addr, void *dest, void *base)
fetch_store_string(unsigned long addr, void *dest, void *base)
{
int maxlen = get_loc_len(*(u32 *)dest);
void *__dest;
@ -94,7 +94,7 @@ kern_fetch_store_string(unsigned long addr, void *dest, void *base)
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
if ((unsigned long)addr < TASK_SIZE)
return kern_fetch_store_string_user(addr, dest, base);
return fetch_store_string_user(addr, dest, base);
#endif
if (unlikely(!maxlen))
@ -112,4 +112,22 @@ kern_fetch_store_string(unsigned long addr, void *dest, void *base)
return ret;
}
static nokprobe_inline int
probe_mem_read_user(void *dest, void *src, size_t size)
{
const void __user *uaddr = (__force const void __user *)src;
return copy_from_user_nofault(dest, uaddr, size);
}
static nokprobe_inline int
probe_mem_read(void *dest, void *src, size_t size)
{
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
if ((unsigned long)src < TASK_SIZE)
return probe_mem_read_user(dest, src, size);
#endif
return copy_from_kernel_nofault(dest, src, size);
}
#endif /* __TRACE_PROBE_KERNEL_H_ */