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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
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);