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| author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2017-04-19 18:21:01 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-04-20 23:18:55 +1000 |
| commit | 290e3070762ac80e5fc4087d8c4de7e3f1d90aca (patch) | |
| tree | c09a1a2111a7db3fa59b077aef7e18f931cdf73d /arch/powerpc/kernel/kprobes.c | |
| parent | 49e0b4658fe6aab5bf6bfe0738a86c1895930ad1 (diff) | |
| download | linux-290e3070762ac80e5fc4087d8c4de7e3f1d90aca.tar.gz linux-290e3070762ac80e5fc4087d8c4de7e3f1d90aca.tar.bz2 linux-290e3070762ac80e5fc4087d8c4de7e3f1d90aca.zip | |
powerpc/kprobes: Fix handling of function offsets on ABIv2
commit 239aeba76409 ("perf powerpc: Fix kprobe and kretprobe handling with
kallsyms on ppc64le") changed how we use the offset field in struct kprobe on
ABIv2. perf now offsets from the global entry point if an offset is specified
and otherwise chooses the local entry point.
Fix the same in kernel for kprobe API users. We do this by extending
kprobe_lookup_name() to accept an additional parameter to indicate the offset
specified with the kprobe registration. If offset is 0, we return the local
function entry and return the global entry point otherwise.
With:
# cd /sys/kernel/debug/tracing/
# echo "p _do_fork" >> kprobe_events
# echo "p _do_fork+0x10" >> kprobe_events
before this patch:
# cat ../kprobes/list
c0000000000d0748 k _do_fork+0x8 [DISABLED]
c0000000000d0758 k _do_fork+0x18 [DISABLED]
c0000000000412b0 k kretprobe_trampoline+0x0 [OPTIMIZED]
and after:
# cat ../kprobes/list
c0000000000d04c8 k _do_fork+0x8 [DISABLED]
c0000000000d04d0 k _do_fork+0x10 [DISABLED]
c0000000000412b0 k kretprobe_trampoline+0x0 [OPTIMIZED]
Acked-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/kprobes.c')
| -rw-r--r-- | arch/powerpc/kernel/kprobes.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index e5f518a962c6..65828fbc410d 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -42,14 +42,14 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); struct kretprobe_blackpoint kretprobe_blacklist[] = {{NULL, NULL}}; -kprobe_opcode_t *kprobe_lookup_name(const char *name) +kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset) { kprobe_opcode_t *addr; #ifdef PPC64_ELF_ABI_v2 /* PPC64 ABIv2 needs local entry point */ addr = (kprobe_opcode_t *)kallsyms_lookup_name(name); - if (addr) + if (addr && !offset) addr = (kprobe_opcode_t *)ppc_function_entry(addr); #elif defined(PPC64_ELF_ABI_v1) /* |