[PATCH v1 04/22] powerpc/ftrace: Use is_offset_in_branch_range()
From: Christophe Leroy <hidden>
Date: 2022-03-24 14:33:07
Also in:
lkml
Subsystem:
function hooks (ftrace), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Steven Rostedt, Masami Hiramatsu, Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Use is_offset_in_branch_range() instead of create_branch() to check if a target is within branch range. This patch together with the previous one improves ftrace activation time by 7% Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/kernel/trace/ftrace.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 3ce3697e8a7c..41c45b9c7f39 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c@@ -89,11 +89,9 @@ ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new) */ static int test_24bit_addr(unsigned long ip, unsigned long addr) { - ppc_inst_t op; addr = ppc_function_entry((void *)addr); - /* use the create_branch to verify that this offset can be branched */ - return create_branch(&op, (u32 *)ip, addr, 0) == 0; + return is_offset_in_branch_range(addr - ip); } static int is_bl_op(ppc_inst_t op)
@@ -261,7 +259,6 @@ __ftrace_make_nop(struct module *mod, static unsigned long find_ftrace_tramp(unsigned long ip) { int i; - ppc_inst_t instr; /* * We have the compiler generated long_branch tramps at the end
@@ -270,8 +267,7 @@ static unsigned long find_ftrace_tramp(unsigned long ip) for (i = NUM_FTRACE_TRAMPS - 1; i >= 0; i--) if (!ftrace_tramps[i]) continue; - else if (create_branch(&instr, (void *)ip, - ftrace_tramps[i], 0) == 0) + else if (is_offset_in_branch_range(ftrace_tramps[i] - ip)) return ftrace_tramps[i]; return 0;
--
2.35.1