[RFC PATCH 2/3] powerpc/ftrace: Override ftrace_location_lookup() for MPROFILE_KERNEL

[Naveen N. Rao]

With CONFIG_MPROFILE_KERNEL, ftrace location is within the first 5
instructions of a function. Override ftrace_location_lookup() to search
within this range for the ftrace location.

Also convert kprobe_lookup_name() to utilize this function.

Signed-off-by: Naveen N. Rao <naveen.n.rao at linux.vnet.ibm.com>
---
 arch/powerpc/kernel/kprobes.c      |  8 +-------
 arch/powerpc/kernel/trace/ftrace.c | 11 +++++++++++
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 9a492fdec1dfbe..03cb50e4c8c3e8 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -50,13 +50,7 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset)
 	addr = (kprobe_opcode_t *)kallsyms_lookup_name(name);
 	if (addr && !offset) {
 #ifdef CONFIG_KPROBES_ON_FTRACE
-		unsigned long faddr;
-		/*
-		 * Per livepatch.h, ftrace location is always within the first
-		 * 16 bytes of a function on powerpc with -mprofile-kernel.
-		 */
-		faddr = ftrace_location_range((unsigned long)addr,
-					      (unsigned long)addr + 16);
+		unsigned long faddr = ftrace_location_lookup((unsigned long)addr);
 		if (faddr)
 			addr = (kprobe_opcode_t *)faddr;
 		else
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index b65ca87a2eacb1..5127eb65c299af 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -1137,3 +1137,14 @@ char *arch_ftrace_match_adjust(char *str, const char *search)
 		return str;
 }
 #endif /* PPC64_ELF_ABI_v1 */
+
+#ifdef CONFIG_MPROFILE_KERNEL
+unsigned long ftrace_location_lookup(unsigned long ip)
+{
+	/*
+	 * Per livepatch.h, ftrace location is always within the first
+	 * 16 bytes of a function on powerpc with -mprofile-kernel.
+	 */
+	return ftrace_location_range(ip, ip + 16);
+}
+#endif
-- 
2.34.1