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authorNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>2017-04-19 18:22:26 +0530
committerMichael Ellerman <mpe@ellerman.id.au>2017-04-24 19:07:58 +1000
commitead514d5fb30a0889d51c0f0e35c3e346165a955 (patch)
treea6fb97f2cfce93e5c8ff10351cd3f4763ae1fc4e /arch/powerpc/kernel/kprobes.c
parent2f59be5b970b503ca8db1cb723b155e455ebac8e (diff)
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powerpc/kprobes: Add support for KPROBES_ON_FTRACE
Allow kprobes to be placed on ftrace _mcount() call sites. This optimization avoids the use of a trap, by riding on ftrace infrastructure. This depends on HAVE_DYNAMIC_FTRACE_WITH_REGS which depends on MPROFILE_KERNEL, which is only currently enabled on powerpc64le with newer toolchains. Based on the x86 code by Masami. 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.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index b71922618ed2..50aabf819787 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -192,7 +192,11 @@ static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
bool arch_function_offset_within_entry(unsigned long offset)
{
#ifdef PPC64_ELF_ABI_v2
+#ifdef CONFIG_KPROBES_ON_FTRACE
+ return offset <= 16;
+#else
return offset <= 8;
+#endif
#else
return !offset;
#endif
@@ -301,7 +305,9 @@ int __kprobes kprobe_handler(struct pt_regs *regs)
}
p = __this_cpu_read(current_kprobe);
if (p->break_handler && p->break_handler(p, regs)) {
- goto ss_probe;
+ if (!skip_singlestep(p, regs, kcb))
+ goto ss_probe;
+ ret = 1;
}
}
goto no_kprobe;