From ae3a2a2188214adc355a5bdf6deb29120886c96f Mon Sep 17 00:00:00 2001
From: Christophe Leroy <christophe.leroy@csgroup.eu>
Date: Mon, 9 May 2022 07:36:00 +0200
Subject: [PATCH] powerpc/ftrace: Remove redundant create_branch() calls
Since commit d5937db114e4 ("powerpc/code-patching: Fix patch_branch()
return on out-of-range failure") patch_branch() fails with -ERANGE
when trying to branch out of range.
No need to perform the test twice. Remove redundant create_branch()
calls.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/aa45fbad0b4b7493080835d8276c0cb4ce146503.1652074503.git.christophe.leroy@csgroup.eu
---
arch/powerpc/kernel/trace/ftrace.c | 20 --------------------
1 file changed, 20 deletions(-)
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 7a266fd469b7..3ce3697e8a7c 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -301,7 +301,6 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
int i;
ppc_inst_t op;
unsigned long ptr;
- ppc_inst_t instr;
static unsigned long ftrace_plt_tramps[NUM_FTRACE_TRAMPS];
/* Is this a known long jump tramp? */
@@ -344,12 +343,6 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
#else
ptr = ppc_global_function_entry((void *)ftrace_caller);
#endif
- if (create_branch(&instr, (void *)tramp, ptr, 0)) {
- pr_debug("%ps is not reachable from existing mcount tramp\n",
- (void *)ptr);
- return -1;
- }
-
if (patch_branch((u32 *)tramp, ptr, 0)) {
pr_debug("REL24 out of range!\n");
return -1;
@@ -490,7 +483,6 @@ static int
__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
{
ppc_inst_t op[2];
- ppc_inst_t instr;
void *ip = (void *)rec->ip;
unsigned long entry, ptr, tramp;
struct module *mod = rec->arch.mod;
@@ -539,12 +531,6 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
return -EINVAL;
}
- /* Ensure branch is within 24 bits */
- if (create_branch(&instr, ip, tramp, BRANCH_SET_LINK)) {
- pr_err("Branch out of range\n");
- return -EINVAL;
- }
-
if (patch_branch(ip, tramp, BRANCH_SET_LINK)) {
pr_err("REL24 out of range!\n");
return -EINVAL;
@@ -770,12 +756,6 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
return -EINVAL;
}
- /* Ensure branch is within 24 bits */
- if (create_branch(&op, (u32 *)ip, tramp, BRANCH_SET_LINK)) {
- pr_err("Branch out of range\n");
- return -EINVAL;
- }
-
if (patch_branch((u32 *)ip, tramp, BRANCH_SET_LINK)) {
pr_err("REL24 out of range!\n");
return -EINVAL;