From: Mark Rutland <mark.rutland@arm.com>
To: Sami Tolvanen <samitolvanen@google.com>
Cc: Kees Cook <keescook@chromium.org>,
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>,
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
Subject: Re: [PATCH v5 16/18] arm64: ftrace: use function_nocfi for ftrace_call
Date: Tue, 6 Apr 2021 12:58:36 +0100 [thread overview]
Message-ID: <20210406115836.GF96480@C02TD0UTHF1T.local> (raw)
In-Reply-To: <20210401233216.2540591-17-samitolvanen@google.com>
On Thu, Apr 01, 2021 at 04:32:14PM -0700, Sami Tolvanen wrote:
> 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);
Acked-by: Mark Rutland <mark.rutland@arm.com>
Thanks,
Mark.
> new = aarch64_insn_gen_branch_imm(pc, (unsigned long)func,
> AARCH64_INSN_BRANCH_LINK);
>
> --
> 2.31.0.208.g409f899ff0-goog
>
next prev parent reply other threads:[~2021-04-06 11:58 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 ` [PATCH v5 16/18] arm64: ftrace: use function_nocfi for ftrace_call Sami Tolvanen
2021-04-06 11:58 ` Mark Rutland [this message]
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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