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powerpc/kprobes: Convert __kprobes to NOKPROBE_SYMBOL()

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Along similar lines as commit 9326638cbe ("kprobes, x86: Use NOKPROBE_SYMBOL()
instead of __kprobes annotation"), convert __kprobes annotation to either
NOKPROBE_SYMBOL() or nokprobe_inline. The latter forces inlining, in which case
the caller needs to be added to NOKPROBE_SYMBOL().

Also:
 - blacklist arch_deref_entry_point(), and
 - convert a few regular inlines to nokprobe_inline in lib/sstep.c

A key benefit is the ability to detect such symbols as being
blacklisted. Before this patch:

  $ cat /sys/kernel/debug/kprobes/blacklist | grep read_mem
  $ perf probe read_mem
  Failed to write event: Invalid argument
    Error: Failed to add events.
  $ dmesg | tail -1
  [ 3736.112815] Could not insert probe at _text+10014968: -22

After patch:
  $ cat /sys/kernel/debug/kprobes/blacklist | grep read_mem
  0xc000000000072b50-0xc000000000072d20	read_mem
  $ perf probe read_mem
  read_mem is blacklisted function, skip it.
  Added new events:
    (null):(null)        (on read_mem)
    probe:read_mem       (on read_mem)

  You can now use it in all perf tools, such as:

	  perf record -e probe:read_mem -aR sleep 1

  $ grep " read_mem" /proc/kallsyms
  c000000000072b50 t read_mem
  c0000000005f3b40 t read_mem
  $ cat /sys/kernel/debug/kprobes/list
  c0000000005f3b48  k  read_mem+0x8    [DISABLED]

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
[mpe: Minor change log formatting, fix up some conflicts]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Naveen N. Rao 2017-04-12 16:48:51 +05:30 committed by Michael Ellerman
parent 700e64377c
commit 71f6e58e5e
3 changed files with 81 additions and 60 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

55
arch/powerpc/kernel/kprobes.c
View File

@ -42,7 +42,7 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
struct kretprobe_blackpoint kretprobe_blacklist[] = {{NULL, NULL}};
int __kprobes arch_prepare_kprobe(struct kprobe *p)
int arch_prepare_kprobe(struct kprobe *p)
{
int ret = 0;
kprobe_opcode_t insn = *p->addr;
@ -74,30 +74,34 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
p->ainsn.boostable = 0;
return ret;
}
NOKPROBE_SYMBOL(arch_prepare_kprobe);
void __kprobes arch_arm_kprobe(struct kprobe *p)
void arch_arm_kprobe(struct kprobe *p)
{
*p->addr = BREAKPOINT_INSTRUCTION;
flush_icache_range((unsigned long) p->addr,
(unsigned long) p->addr + sizeof(kprobe_opcode_t));
}
NOKPROBE_SYMBOL(arch_arm_kprobe);
void __kprobes arch_disarm_kprobe(struct kprobe *p)
void arch_disarm_kprobe(struct kprobe *p)
{
*p->addr = p->opcode;
flush_icache_range((unsigned long) p->addr,
(unsigned long) p->addr + sizeof(kprobe_opcode_t));
}
NOKPROBE_SYMBOL(arch_disarm_kprobe);
void __kprobes arch_remove_kprobe(struct kprobe *p)
void arch_remove_kprobe(struct kprobe *p)
{
if (p->ainsn.insn) {
free_insn_slot(p->ainsn.insn, 0);
p->ainsn.insn = NULL;
}
}
NOKPROBE_SYMBOL(arch_remove_kprobe);
static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
static nokprobe_inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
{
enable_single_step(regs);
@ -110,37 +114,37 @@ static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
regs->nip = (unsigned long)p->ainsn.insn;
}
static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
static nokprobe_inline void save_previous_kprobe(struct kprobe_ctlblk *kcb)
{
kcb->prev_kprobe.kp = kprobe_running();
kcb->prev_kprobe.status = kcb->kprobe_status;
kcb->prev_kprobe.saved_msr = kcb->kprobe_saved_msr;
}
static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
static nokprobe_inline void restore_previous_kprobe(struct kprobe_ctlblk *kcb)
{
__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
kcb->kprobe_status = kcb->prev_kprobe.status;
kcb->kprobe_saved_msr = kcb->prev_kprobe.saved_msr;
}
static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
static nokprobe_inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
struct kprobe_ctlblk *kcb)
{
__this_cpu_write(current_kprobe, p);
kcb->kprobe_saved_msr = regs->msr;
}
void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs)
void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs)
{
ri->ret_addr = (kprobe_opcode_t *)regs->link;
/* Replace the return addr with trampoline addr */
regs->link = (unsigned long)kretprobe_trampoline;
}
NOKPROBE_SYMBOL(arch_prepare_kretprobe);
int __kprobes kprobe_handler(struct pt_regs *regs)
int kprobe_handler(struct pt_regs *regs)
{
struct kprobe *p;
int ret = 0;
@ -273,6 +277,7 @@ no_kprobe:
preempt_enable_no_resched();
return ret;
}
NOKPROBE_SYMBOL(kprobe_handler);
/*
* Function return probe trampoline:
@ -290,8 +295,7 @@ asm(".global kretprobe_trampoline\n"
/*
* Called when the probe at kretprobe trampoline is hit
*/
static int __kprobes trampoline_probe_handler(struct kprobe *p,
struct pt_regs *regs)
static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
{
struct kretprobe_instance *ri = NULL;
struct hlist_head *head, empty_rp;
@ -360,6 +364,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
*/
return 1;
}
NOKPROBE_SYMBOL(trampoline_probe_handler);
/*
* Called after single-stepping. p->addr is the address of the
@ -369,7 +374,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
* single-stepped a copy of the instruction. The address of this
* copy is p->ainsn.insn.
*/
int __kprobes kprobe_post_handler(struct pt_regs *regs)
int kprobe_post_handler(struct pt_regs *regs)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
@ -409,8 +414,9 @@ out:
return 1;
}
NOKPROBE_SYMBOL(kprobe_post_handler);
int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
@ -473,13 +479,15 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
}
return 0;
}
NOKPROBE_SYMBOL(kprobe_fault_handler);
unsigned long arch_deref_entry_point(void *entry)
{
return ppc_global_function_entry(entry);
}
NOKPROBE_SYMBOL(arch_deref_entry_point);
int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
{
struct jprobe *jp = container_of(p, struct jprobe, kp);
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
@ -496,17 +504,20 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
return 1;
}
NOKPROBE_SYMBOL(setjmp_pre_handler);
void __used __kprobes jprobe_return(void)
void __used jprobe_return(void)
{
asm volatile("trap" ::: "memory");
}
NOKPROBE_SYMBOL(jprobe_return);
static void __used __kprobes jprobe_return_end(void)
static void __used jprobe_return_end(void)
{
};
}
NOKPROBE_SYMBOL(jprobe_return_end);
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
{
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
@ -519,6 +530,7 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
preempt_enable_no_resched();
return 1;
}
NOKPROBE_SYMBOL(longjmp_break_handler);
static struct kprobe trampoline_p = {
.addr = (kprobe_opcode_t *) &kretprobe_trampoline,
@ -530,10 +542,11 @@ int __init arch_init_kprobes(void)
return register_kprobe(&trampoline_p);
}
int __kprobes arch_trampoline_kprobe(struct kprobe *p)
int arch_trampoline_kprobe(struct kprobe *p)
{
if (p->addr == (kprobe_opcode_t *)&kretprobe_trampoline)
return 1;
return 0;
}
NOKPROBE_SYMBOL(arch_trampoline_kprobe);

4
arch/powerpc/lib/code-patching.c
View File

@ -8,6 +8,7 @@
*/
#include <linux/kernel.h>
#include <linux/kprobes.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/mm.h>
@ -59,7 +60,7 @@ bool is_offset_in_branch_range(long offset)
* Helper to check if a given instruction is a conditional branch
* Derived from the conditional checks in analyse_instr()
*/
bool __kprobes is_conditional_branch(unsigned int instr)
bool is_conditional_branch(unsigned int instr)
{
unsigned int opcode = instr >> 26;
@ -75,6 +76,7 @@ bool __kprobes is_conditional_branch(unsigned int instr)
}
return false;
}
NOKPROBE_SYMBOL(is_conditional_branch);
unsigned int create_branch(const unsigned int *addr,
unsigned long target, int flags)

82
arch/powerpc/lib/sstep.c
View File

@ -49,7 +49,8 @@ extern int do_stxvd2x(int rn, unsigned long ea);
/*
* Emulate the truncation of 64 bit values in 32-bit mode.
*/
static unsigned long truncate_if_32bit(unsigned long msr, unsigned long val)
static nokprobe_inline unsigned long truncate_if_32bit(unsigned long msr,
unsigned long val)
{
#ifdef __powerpc64__
if ((msr & MSR_64BIT) == 0)
@ -61,7 +62,7 @@ static unsigned long truncate_if_32bit(unsigned long msr, unsigned long val)
/*
* Determine whether a conditional branch instruction would branch.
*/
static int __kprobes branch_taken(unsigned int instr, struct pt_regs *regs)
static nokprobe_inline int branch_taken(unsigned int instr, struct pt_regs *regs)
{
unsigned int bo = (instr >> 21) & 0x1f;
unsigned int bi;
@ -81,8 +82,7 @@ static int __kprobes branch_taken(unsigned int instr, struct pt_regs *regs)
return 1;
}
static long __kprobes address_ok(struct pt_regs *regs, unsigned long ea, int nb)
static nokprobe_inline long address_ok(struct pt_regs *regs, unsigned long ea, int nb)
{
if (!user_mode(regs))
return 1;
@ -92,7 +92,7 @@ static long __kprobes address_ok(struct pt_regs *regs, unsigned long ea, int nb)
/*
* Calculate effective address for a D-form instruction
*/
static unsigned long __kprobes dform_ea(unsigned int instr, struct pt_regs *regs)
static nokprobe_inline unsigned long dform_ea(unsigned int instr, struct pt_regs *regs)
{
int ra;
unsigned long ea;
@ -109,7 +109,7 @@ static unsigned long __kprobes dform_ea(unsigned int instr, struct pt_regs *regs
/*
* Calculate effective address for a DS-form instruction
*/
static unsigned long __kprobes dsform_ea(unsigned int instr, struct pt_regs *regs)
static nokprobe_inline unsigned long dsform_ea(unsigned int instr, struct pt_regs *regs)
{
int ra;
unsigned long ea;
@ -126,8 +126,8 @@ static unsigned long __kprobes dsform_ea(unsigned int instr, struct pt_regs *reg
/*
* Calculate effective address for an X-form instruction
*/
static unsigned long __kprobes xform_ea(unsigned int instr,
struct pt_regs *regs)
static nokprobe_inline unsigned long xform_ea(unsigned int instr,
struct pt_regs *regs)
{
int ra, rb;
unsigned long ea;
@ -145,33 +145,33 @@ static unsigned long __kprobes xform_ea(unsigned int instr,
* Return the largest power of 2, not greater than sizeof(unsigned long),
* such that x is a multiple of it.
*/
static inline unsigned long max_align(unsigned long x)
static nokprobe_inline unsigned long max_align(unsigned long x)
{
x |= sizeof(unsigned long);
return x & -x; /* isolates rightmost bit */
}
static inline unsigned long byterev_2(unsigned long x)
static nokprobe_inline unsigned long byterev_2(unsigned long x)
{
return ((x >> 8) & 0xff) | ((x & 0xff) << 8);
}
static inline unsigned long byterev_4(unsigned long x)
static nokprobe_inline unsigned long byterev_4(unsigned long x)
{
return ((x >> 24) & 0xff) | ((x >> 8) & 0xff00) |
((x & 0xff00) << 8) | ((x & 0xff) << 24);
}
#ifdef __powerpc64__
static inline unsigned long byterev_8(unsigned long x)
static nokprobe_inline unsigned long byterev_8(unsigned long x)
{
return (byterev_4(x) << 32) | byterev_4(x >> 32);
}
#endif
static int __kprobes read_mem_aligned(unsigned long *dest, unsigned long ea,
int nb)
static nokprobe_inline int read_mem_aligned(unsigned long *dest,
unsigned long ea, int nb)
{
int err = 0;
unsigned long x = 0;
@ -197,8 +197,8 @@ static int __kprobes read_mem_aligned(unsigned long *dest, unsigned long ea,
return err;
}
static int __kprobes read_mem_unaligned(unsigned long *dest, unsigned long ea,
int nb, struct pt_regs *regs)
static nokprobe_inline int read_mem_unaligned(unsigned long *dest,
unsigned long ea, int nb, struct pt_regs *regs)
{
int err;
unsigned long x, b, c;
@ -248,7 +248,7 @@ static int __kprobes read_mem_unaligned(unsigned long *dest, unsigned long ea,
* Read memory at address ea for nb bytes, return 0 for success
* or -EFAULT if an error occurred.
*/
static int __kprobes read_mem(unsigned long *dest, unsigned long ea, int nb,
static int read_mem(unsigned long *dest, unsigned long ea, int nb,
struct pt_regs *regs)
{
if (!address_ok(regs, ea, nb))
@ -257,9 +257,10 @@ static int __kprobes read_mem(unsigned long *dest, unsigned long ea, int nb,
return read_mem_aligned(dest, ea, nb);
return read_mem_unaligned(dest, ea, nb, regs);
}
NOKPROBE_SYMBOL(read_mem);
static int __kprobes write_mem_aligned(unsigned long val, unsigned long ea,
int nb)
static nokprobe_inline int write_mem_aligned(unsigned long val,
unsigned long ea, int nb)
{
int err = 0;
@ -282,8 +283,8 @@ static int __kprobes write_mem_aligned(unsigned long val, unsigned long ea,
return err;
}
static int __kprobes write_mem_unaligned(unsigned long val, unsigned long ea,
int nb, struct pt_regs *regs)
static nokprobe_inline int write_mem_unaligned(unsigned long val,
unsigned long ea, int nb, struct pt_regs *regs)
{
int err;
unsigned long c;
@ -325,7 +326,7 @@ static int __kprobes write_mem_unaligned(unsigned long val, unsigned long ea,
* Write memory at address ea for nb bytes, return 0 for success
* or -EFAULT if an error occurred.
*/
static int __kprobes write_mem(unsigned long val, unsigned long ea, int nb,
static int write_mem(unsigned long val, unsigned long ea, int nb,
struct pt_regs *regs)
{
if (!address_ok(regs, ea, nb))
@ -334,13 +335,14 @@ static int __kprobes write_mem(unsigned long val, unsigned long ea, int nb,
return write_mem_aligned(val, ea, nb);
return write_mem_unaligned(val, ea, nb, regs);
}
NOKPROBE_SYMBOL(write_mem);
#ifdef CONFIG_PPC_FPU
/*
* Check the address and alignment, and call func to do the actual
* load or store.
*/
static int __kprobes do_fp_load(int rn, int (*func)(int, unsigned long),
static int do_fp_load(int rn, int (*func)(int, unsigned long),
unsigned long ea, int nb,
struct pt_regs *regs)
{
@ -380,8 +382,9 @@ static int __kprobes do_fp_load(int rn, int (*func)(int, unsigned long),
return err;
return (*func)(rn, ptr);
}
NOKPROBE_SYMBOL(do_fp_load);
static int __kprobes do_fp_store(int rn, int (*func)(int, unsigned long),
static int do_fp_store(int rn, int (*func)(int, unsigned long),
unsigned long ea, int nb,
struct pt_regs *regs)
{
@ -425,11 +428,12 @@ static int __kprobes do_fp_store(int rn, int (*func)(int, unsigned long),
}
return err;
}
NOKPROBE_SYMBOL(do_fp_store);
#endif
#ifdef CONFIG_ALTIVEC
/* For Altivec/VMX, no need to worry about alignment */
static int __kprobes do_vec_load(int rn, int (*func)(int, unsigned long),
static nokprobe_inline int do_vec_load(int rn, int (*func)(int, unsigned long),
unsigned long ea, struct pt_regs *regs)
{
if (!address_ok(regs, ea & ~0xfUL, 16))
@ -437,7 +441,7 @@ static int __kprobes do_vec_load(int rn, int (*func)(int, unsigned long),
return (*func)(rn, ea);
}
static int __kprobes do_vec_store(int rn, int (*func)(int, unsigned long),
static nokprobe_inline int do_vec_store(int rn, int (*func)(int, unsigned long),
unsigned long ea, struct pt_regs *regs)
{
if (!address_ok(regs, ea & ~0xfUL, 16))
@ -447,7 +451,7 @@ static int __kprobes do_vec_store(int rn, int (*func)(int, unsigned long),
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_VSX
static int __kprobes do_vsx_load(int rn, int (*func)(int, unsigned long),
static nokprobe_inline int do_vsx_load(int rn, int (*func)(int, unsigned long),
unsigned long ea, struct pt_regs *regs)
{
int err;
@ -465,7 +469,7 @@ static int __kprobes do_vsx_load(int rn, int (*func)(int, unsigned long),
return err;
}
static int __kprobes do_vsx_store(int rn, int (*func)(int, unsigned long),
static nokprobe_inline int do_vsx_store(int rn, int (*func)(int, unsigned long),
unsigned long ea, struct pt_regs *regs)
{
int err;
@ -522,7 +526,7 @@ static int __kprobes do_vsx_store(int rn, int (*func)(int, unsigned long),
: "=r" (err) \
: "r" (addr), "i" (-EFAULT), "0" (err))
static void __kprobes set_cr0(struct pt_regs *regs, int rd)
static nokprobe_inline void set_cr0(struct pt_regs *regs, int rd)
{
long val = regs->gpr[rd];
@ -539,7 +543,7 @@ static void __kprobes set_cr0(struct pt_regs *regs, int rd)
regs->ccr |= 0x20000000;
}
static void __kprobes add_with_carry(struct pt_regs *regs, int rd,
static nokprobe_inline void add_with_carry(struct pt_regs *regs, int rd,
unsigned long val1, unsigned long val2,
unsigned long carry_in)
{
@ -560,7 +564,7 @@ static void __kprobes add_with_carry(struct pt_regs *regs, int rd,
regs->xer &= ~XER_CA;
}
static void __kprobes do_cmp_signed(struct pt_regs *regs, long v1, long v2,
static nokprobe_inline void do_cmp_signed(struct pt_regs *regs, long v1, long v2,
int crfld)
{
unsigned int crval, shift;
@ -576,7 +580,7 @@ static void __kprobes do_cmp_signed(struct pt_regs *regs, long v1, long v2,
regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
}
static void __kprobes do_cmp_unsigned(struct pt_regs *regs, unsigned long v1,
static nokprobe_inline void do_cmp_unsigned(struct pt_regs *regs, unsigned long v1,
unsigned long v2, int crfld)
{
unsigned int crval, shift;
@ -592,7 +596,7 @@ static void __kprobes do_cmp_unsigned(struct pt_regs *regs, unsigned long v1,
regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
}
static int __kprobes trap_compare(long v1, long v2)
static nokprobe_inline int trap_compare(long v1, long v2)
{
int ret = 0;
@ -631,7 +635,7 @@ static int __kprobes trap_compare(long v1, long v2)
* Returns 1 if the instruction has been executed, or 0 if not.
* Sets *op to indicate what the instruction does.
*/
int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
unsigned int instr)
{
unsigned int opcode, ra, rb, rd, spr, u;
@ -1692,6 +1696,7 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
#endif
}
EXPORT_SYMBOL_GPL(analyse_instr);
NOKPROBE_SYMBOL(analyse_instr);
/*
* For PPC32 we always use stwu with r1 to change the stack pointer.
@ -1701,7 +1706,7 @@ EXPORT_SYMBOL_GPL(analyse_instr);
* don't emulate the real store operation. We will do real store
* operation safely in exception return code by checking this flag.
*/
static __kprobes int handle_stack_update(unsigned long ea, struct pt_regs *regs)
static nokprobe_inline int handle_stack_update(unsigned long ea, struct pt_regs *regs)
{
#ifdef CONFIG_PPC32
/*
@ -1721,7 +1726,7 @@ static __kprobes int handle_stack_update(unsigned long ea, struct pt_regs *regs)
return 0;
}
static __kprobes void do_signext(unsigned long *valp, int size)
static nokprobe_inline void do_signext(unsigned long *valp, int size)
{
switch (size) {
case 2:
@ -1733,7 +1738,7 @@ static __kprobes void do_signext(unsigned long *valp, int size)
}
}
static __kprobes void do_byterev(unsigned long *valp, int size)
static nokprobe_inline void do_byterev(unsigned long *valp, int size)
{
switch (size) {
case 2:
@ -1757,7 +1762,7 @@ static __kprobes void do_byterev(unsigned long *valp, int size)
* or -1 if the instruction is one that should not be stepped,
* such as an rfid, or a mtmsrd that would clear MSR_RI.
*/
int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
int emulate_step(struct pt_regs *regs, unsigned int instr)
{
struct instruction_op op;
int r, err, size;
@ -1988,3 +1993,4 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
return 1;
}
NOKPROBE_SYMBOL(emulate_step);