From: Thomas Gleixner <tglx@linutronix.de>
To: Sami Tolvanen <samitolvanen@google.com>, Borislav Petkov <bp@alien8.de>
Cc: X86 ML <x86@kernel.org>, Kees Cook <keescook@chromium.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Sedat Dilek <sedat.dilek@gmail.com>,
linux-hardening@vger.kernel.org,
LKML <linux-kernel@vger.kernel.org>,
clang-built-linux <clang-built-linux@googlegroups.com>
Subject: Re: [PATCH 05/15] x86: Implement function_nocfi
Date: Sat, 17 Apr 2021 00:13:29 +0200 [thread overview]
Message-ID: <87mttxubcm.ffs@nanos.tec.linutronix.de> (raw)
In-Reply-To: <CABCJKud8TvzhcjHCpsrtCJ4B50ZUfaL48F42EhZ2zWKLteAc0Q@mail.gmail.com>
On Fri, Apr 16 2021 at 14:49, Sami Tolvanen wrote:
> On Fri, Apr 16, 2021 at 2:18 PM Borislav Petkov <bp@alien8.de> wrote:
>> In file included from ./include/linux/ftrace.h:22:0,
>> from ./include/linux/init_task.h:9,
>> from init/init_task.c:2:
>> ./include/linux/ftrace.h: In function ‘ftrace_init_nop’:
>> ./arch/x86/include/asm/ftrace.h:9:40: error: implicit declaration of function ‘function_nocfi’ [-Werror=implicit-function-declaration]
>
> This is defined in linux-next, but I do see another issue, which I'll
> fix in v2. Note that CFI_CLANG itself cannot be selected on 32-bit
> x86.
Sure and because of that it's overrated to make sure that it does not
break the build. I know, sekurity ...
But aside of that when looking at the rest of the series, then I really
have to ask whether the only way to address this is to make a large
amount of code unreadable like this:
- wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64);
+ wrmsrl(MSR_LSTAR, (unsigned long)function_nocfi(entry_SYSCALL_64));
plus a gazillion of similar changes.
This is unreadable garbage.
Thanks,
tglx
next prev parent reply other threads:[~2021-04-16 22:13 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-16 20:38 [PATCH 00/15] x86: Add support for Clang CFI Sami Tolvanen
2021-04-16 20:38 ` [PATCH 01/15] objtool: Find a destination for jumps beyond the section end Sami Tolvanen
2021-04-20 18:14 ` Josh Poimboeuf
2021-04-20 20:25 ` Sami Tolvanen
2021-04-20 22:55 ` Josh Poimboeuf
2021-04-20 22:58 ` Nick Desaulniers
2021-04-16 20:38 ` [PATCH 02/15] objtool: Add CONFIG_CFI_CLANG support Sami Tolvanen
2021-04-20 19:47 ` Josh Poimboeuf
2021-04-20 20:45 ` Sami Tolvanen
2021-04-16 20:38 ` [PATCH 03/15] objtool: Add ASM_STACK_FRAME_NON_STANDARD Sami Tolvanen
2021-04-16 20:38 ` [PATCH 04/15] static_call: Use global functions for the self-test Sami Tolvanen
2021-04-16 21:37 ` Thomas Gleixner
2021-04-17 0:16 ` Thomas Gleixner
2021-04-16 20:38 ` [PATCH 05/15] x86: Implement function_nocfi Sami Tolvanen
2021-04-16 21:18 ` Borislav Petkov
2021-04-16 21:49 ` Sami Tolvanen
2021-04-16 22:02 ` Borislav Petkov
2021-04-16 22:06 ` Andy Lutomirski
2021-04-16 22:14 ` Borislav Petkov
2021-04-16 22:20 ` Andy Lutomirski
2021-04-16 22:37 ` Kees Cook
2021-04-16 23:02 ` Thomas Gleixner
2021-04-17 10:16 ` Thomas Gleixner
2021-04-19 15:13 ` Sami Tolvanen
2021-04-16 22:28 ` Kees Cook
2021-04-16 22:52 ` Andy Lutomirski
2021-04-16 22:58 ` Kees Cook
2021-04-16 23:40 ` Kees Cook
2021-04-17 23:19 ` Andy Lutomirski
2021-04-17 23:53 ` Thomas Gleixner
2021-04-18 0:11 ` Andy Lutomirski
2021-04-18 16:17 ` Thomas Gleixner
2021-04-18 22:57 ` Andy Lutomirski
2021-04-19 15:20 ` Sami Tolvanen
2021-04-19 15:26 ` David Laight
2021-04-19 17:46 ` Andy Lutomirski
2021-04-17 14:20 ` David Laight
2021-04-17 15:48 ` Andy Lutomirski
2021-04-19 8:40 ` Rasmus Villemoes
2021-04-19 16:45 ` Joao Moreira
2021-04-19 21:52 ` David Laight
2021-04-16 22:16 ` Kees Cook
2021-04-16 22:13 ` Thomas Gleixner [this message]
2021-04-16 20:38 ` [PATCH 06/15] x86: Avoid CFI jump tables in IDT and entry points Sami Tolvanen
2021-04-16 22:26 ` Thomas Gleixner
2021-04-16 23:56 ` Kees Cook
2021-04-17 0:02 ` Thomas Gleixner
2021-04-16 20:38 ` [PATCH 07/15] x86/ftrace: Use function_nocfi in MCOUNT_ADDR Sami Tolvanen
2021-04-16 20:38 ` [PATCH 08/15] x86/extable: Do not mark exception callback as CFI Sami Tolvanen
2021-04-16 20:38 ` [PATCH 09/15] x86/alternatives: Use C int3 selftest but disable KASAN Sami Tolvanen
2021-04-17 11:37 ` Peter Zijlstra
2021-04-19 15:26 ` Sami Tolvanen
2021-04-20 7:19 ` Peter Zijlstra
2021-04-16 20:38 ` [PATCH 10/15] x86/purgatory: Disable CFI Sami Tolvanen
2021-04-16 20:38 ` [PATCH 11/15] x86, relocs: Ignore __typeid__ relocations Sami Tolvanen
2021-04-16 20:38 ` [PATCH 12/15] x86, module: " Sami Tolvanen
2021-04-16 20:38 ` [PATCH 13/15] x86, cpu: Use LTO for cpu.c with CFI Sami Tolvanen
2021-04-16 20:38 ` [PATCH 14/15] x86, kprobes: Fix optprobe_template_func type mismatch Sami Tolvanen
2021-04-16 20:38 ` [PATCH 15/15] x86, build: Allow CONFIG_CFI_CLANG to be selected Sami Tolvanen
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