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From: Sami Tolvanen <samitolvanen@google.com>
To: Kees Cook <keescook@chromium.org>
Cc: Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Will Deacon <will@kernel.org>, Jessica Yu <jeyu@kernel.org>,
	Arnd Bergmann <arnd@arndb.de>, Tejun Heo <tj@kernel.org>,
	"Paul E. McKenney" <paulmck@kernel.org>,
	Christoph Hellwig <hch@infradead.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Sedat Dilek <sedat.dilek@gmail.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	bpf@vger.kernel.org, linux-hardening@vger.kernel.org,
	linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org,
	linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com,
	Sami Tolvanen <samitolvanen@google.com>
Subject: [PATCH v5 16/18] arm64: ftrace: use function_nocfi for ftrace_call
Date: Thu,  1 Apr 2021 16:32:14 -0700	[thread overview]
Message-ID: <20210401233216.2540591-17-samitolvanen@google.com> (raw)
In-Reply-To: <20210401233216.2540591-1-samitolvanen@google.com>

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@unisoc.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
 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);
 
-- 
2.31.0.208.g409f899ff0-goog


  parent reply	other threads:[~2021-04-01 23:34 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-01 23:31 [PATCH v5 00/18] Add support for Clang CFI Sami Tolvanen
2021-04-01 23:31 ` [PATCH v5 01/18] add " Sami Tolvanen
2021-04-01 23:32 ` [PATCH v5 02/18] cfi: add __cficanonical Sami Tolvanen
2021-04-01 23:32 ` [PATCH v5 03/18] mm: add generic function_nocfi macro Sami Tolvanen
2021-04-02  6:37   ` Christoph Hellwig
2021-04-06 11:27   ` Mark Rutland
2021-04-01 23:32 ` [PATCH v5 04/18] module: ensure __cfi_check alignment Sami Tolvanen
2021-04-01 23:32 ` [PATCH v5 05/18] workqueue: use WARN_ON_FUNCTION_MISMATCH Sami Tolvanen
2021-04-01 23:32 ` [PATCH v5 06/18] kthread: " Sami Tolvanen
2021-04-01 23:32 ` [PATCH v5 07/18] kallsyms: strip ThinLTO hashes from static functions Sami Tolvanen
2021-04-01 23:32 ` [PATCH v5 08/18] bpf: disable CFI in dispatcher functions Sami Tolvanen
2021-04-01 23:32 ` [PATCH v5 09/18] treewide: Change list_sort to use const pointers Sami Tolvanen
2021-04-01 23:32 ` [PATCH v5 10/18] lkdtm: use function_nocfi Sami Tolvanen
2021-04-01 23:32 ` [PATCH v5 11/18] psci: use function_nocfi for cpu_resume Sami Tolvanen
2021-04-06 11:27   ` Mark Rutland
2021-04-01 23:32 ` [PATCH v5 12/18] arm64: implement function_nocfi Sami Tolvanen
2021-04-06 11:36   ` Mark Rutland
2021-04-06 17:02     ` Sami Tolvanen
2021-04-01 23:32 ` [PATCH v5 13/18] arm64: use function_nocfi with __pa_symbol Sami Tolvanen
2021-04-06 11:41   ` Mark Rutland
2021-04-01 23:32 ` [PATCH v5 14/18] arm64: add __nocfi to functions that jump to a physical address Sami Tolvanen
2021-04-06 11:53   ` Mark Rutland
2021-04-06 12:59     ` Ard Biesheuvel
2021-04-06 17:43     ` Sami Tolvanen
2021-04-01 23:32 ` [PATCH v5 15/18] arm64: add __nocfi to __apply_alternatives Sami Tolvanen
2021-04-01 23:32 ` Sami Tolvanen [this message]
2021-04-06 11:58   ` [PATCH v5 16/18] arm64: ftrace: use function_nocfi for ftrace_call Mark Rutland
2021-04-01 23:32 ` [PATCH v5 17/18] KVM: arm64: Disable CFI for nVHE Sami Tolvanen
2021-04-01 23:32 ` [PATCH v5 18/18] arm64: allow CONFIG_CFI_CLANG to be selected Sami Tolvanen
2021-04-02 19:58 ` [PATCH v5 00/18] Add support for Clang CFI Nathan Chancellor

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