diff options
| author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2017-09-22 14:40:45 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-10-04 23:42:17 +1100 |
| commit | bf3a91251735863fcb230c96e984ebcacee820d9 (patch) | |
| tree | a54610879baee8bc1b545f6e958e97aae080eec4 | |
| parent | a7b440383f9b078254d38ab6a3672810f1eca74f (diff) | |
| download | linux-bf3a91251735863fcb230c96e984ebcacee820d9.tar.gz | |
powerpc/kprobes: Clean up jprobe detection in livepatch handler
In commit c05b8c4474c03 ("powerpc/kprobes: Skip livepatch_handler() for
jprobes"), we added a helper is_current_kprobe_addr() to help detect if
the modified regs->nip was due to a jprobe or livepatch. Masami felt
that the function name was not quite clear. To that end, this patch
renames is_current_kprobe_addr() to __is_active_jprobe() and adds a
comment to (hopefully) better clarify the purpose of this helper. The
helper has also now been moved to kprobes-ftrace.c so that it is only
available for KPROBES_ON_FTRACE.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/include/asm/kprobes.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/kernel/kprobes-ftrace.c | 11 | ||||
| -rw-r--r-- | arch/powerpc/kernel/kprobes.c | 6 | ||||
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace_64_mprofile.S | 4 |
4 files changed, 14 insertions, 9 deletions
diff --git a/arch/powerpc/include/asm/kprobes.h b/arch/powerpc/include/asm/kprobes.h index 8814a7249ceb..9f3be5c8a4a3 100644 --- a/arch/powerpc/include/asm/kprobes.h +++ b/arch/powerpc/include/asm/kprobes.h @@ -103,8 +103,8 @@ extern int kprobe_exceptions_notify(struct notifier_block *self, extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr); extern int kprobe_handler(struct pt_regs *regs); extern int kprobe_post_handler(struct pt_regs *regs); -extern int is_current_kprobe_addr(unsigned long addr); #ifdef CONFIG_KPROBES_ON_FTRACE +extern int __is_active_jprobe(unsigned long addr); extern int skip_singlestep(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb); #else diff --git a/arch/powerpc/kernel/kprobes-ftrace.c b/arch/powerpc/kernel/kprobes-ftrace.c index 6c089d9757c9..48f675a73cff 100644 --- a/arch/powerpc/kernel/kprobes-ftrace.c +++ b/arch/powerpc/kernel/kprobes-ftrace.c @@ -25,6 +25,17 @@ #include <linux/preempt.h> #include <linux/ftrace.h> +/* + * This is called from ftrace code after invoking registered handlers to + * disambiguate regs->nip changes done by jprobes and livepatch. We check if + * there is an active jprobe at the provided address (mcount location). + */ +int __is_active_jprobe(unsigned long addr) +{ + struct kprobe *p = kprobe_running(); + return (p && (unsigned long)p->addr == addr) ? 1 : 0; +} + static nokprobe_inline int __skip_singlestep(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb, unsigned long orig_nip) diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 4c1702423676..48a81614f629 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -43,12 +43,6 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); struct kretprobe_blackpoint kretprobe_blacklist[] = {{NULL, NULL}}; -int is_current_kprobe_addr(unsigned long addr) -{ - struct kprobe *p = kprobe_running(); - return (p && (unsigned long)p->addr == addr) ? 1 : 0; -} - bool arch_within_kprobe_blacklist(unsigned long addr) { return (addr >= (unsigned long)__kprobes_text_start && diff --git a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S index c98e90b4ea7b..c1cfcce0551d 100644 --- a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S +++ b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S @@ -110,9 +110,9 @@ ftrace_call: /* NIP has not been altered, skip over further checks */ beq 1f - /* Check if there is an active kprobe on us */ + /* Check if there is an active jprobe on us */ subi r3, r14, 4 - bl is_current_kprobe_addr + bl __is_active_jprobe nop /* |