[PATCH v6 16/18] arm64: ftrace: use function_nocfi for ftrace_call
Sami Tolvanen
samitolvanen at google.com
Thu Apr 8 19:28:41 BST 2021
With CONFIG_CFI_CLANG, the compiler replaces function pointers with
jump table addresses, which breaks dynamic ftrace as the address of
ftrace_call is replaced with the address of ftrace_call.cfi_jt. Use
function_nocfi() to get the address of the actual function instead.
Suggested-by: Ben Dai <ben.dai at unisoc.com>
Signed-off-by: Sami Tolvanen <samitolvanen at google.com>
Acked-by: Mark Rutland <mark.rutland at arm.com>
Tested-by: Nathan Chancellor <nathan at kernel.org>
---
arch/arm64/kernel/ftrace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c
index 86a5cf9bc19a..b5d3ddaf69d9 100644
--- a/arch/arm64/kernel/ftrace.c
+++ b/arch/arm64/kernel/ftrace.c
@@ -55,7 +55,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
unsigned long pc;
u32 new;
- pc = (unsigned long)&ftrace_call;
+ pc = (unsigned long)function_nocfi(ftrace_call);
new = aarch64_insn_gen_branch_imm(pc, (unsigned long)func,
AARCH64_INSN_BRANCH_LINK);
--
2.31.1.295.g9ea45b61b8-goog
More information about the linux-arm-kernel
mailing list