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Message-Id: <20210408182843.1754385-17-samitolvanen@google.com>
Date: Thu, 8 Apr 2021 11:28:41 -0700
From: Sami Tolvanen <samitolvanen@...gle.com>
To: Kees Cook <keescook@...omium.org>
Cc: Nathan Chancellor <nathan@...nel.org>,
Nick Desaulniers <ndesaulniers@...gle.com>,
Masahiro Yamada <masahiroy@...nel.org>,
Will Deacon <will@...nel.org>, Jessica Yu <jeyu@...nel.org>,
Arnd Bergmann <arnd@...db.de>, Tejun Heo <tj@...nel.org>,
"Paul E. McKenney" <paulmck@...nel.org>,
Christoph Hellwig <hch@...radead.org>,
Peter Zijlstra <peterz@...radead.org>,
Sedat Dilek <sedat.dilek@...il.com>,
Mark Rutland <mark.rutland@....com>,
Catalin Marinas <catalin.marinas@....com>, bpf@...r.kernel.org,
linux-hardening@...r.kernel.org, linux-arch@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org, linux-kbuild@...r.kernel.org,
linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
clang-built-linux@...glegroups.com,
Sami Tolvanen <samitolvanen@...gle.com>
Subject: [PATCH v6 16/18] arm64: ftrace: use function_nocfi for ftrace_call
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@...soc.com>
Signed-off-by: Sami Tolvanen <samitolvanen@...gle.com>
Acked-by: Mark Rutland <mark.rutland@....com>
Tested-by: Nathan Chancellor <nathan@...nel.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
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