From: Brian Gerst <brgerst@gmail.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>, "H . Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
Sami Tolvanen <samitolvanen@google.com>,
alyssa.milburn@linux.intel.com, keescook@chromium.org,
jpoimboe@kernel.org, joao@overdrivepizza.com,
tim.c.chen@linux.intel.com, Brian Gerst <brgerst@gmail.com>
Subject: [PATCH v2 0/2] Rewrite ret_from_fork() in C
Date: Fri, 23 Jun 2023 18:55:27 -0400 [thread overview]
Message-ID: <20230623225529.34590-1-brgerst@gmail.com> (raw)
When kCFI is enabled, special handling is needed for the indirect call
to the kernel thread function. Handling this in pure assembly is not
simple, so moving it to C is more appropriate. Instead of moving just
the indirect call to C as Peter Zijlstra has proposed, this patchset
rewrites the whole ret_from_fork() function in C (other than some
necessary asm glue remaning).
V2:
- Fixed wrong address of pt_regs being passed
- Simplified 64-bit asm stub to not use a tail-call
Brian Gerst (2):
x86/32: Remove schedule_tail_wrapper()
x86: Rewrite ret_from_fork() in C
arch/x86/entry/entry_32.S | 53 ++++++++------------------------
arch/x86/entry/entry_64.S | 33 +++++---------------
arch/x86/include/asm/switch_to.h | 4 ++-
arch/x86/kernel/process.c | 22 ++++++++++++-
4 files changed, 45 insertions(+), 67 deletions(-)
--
2.41.0
next reply other threads:[~2023-06-23 22:56 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-23 22:55 Brian Gerst [this message]
2023-06-23 22:55 ` [PATCH v2 1/2] x86/32: Remove schedule_tail_wrapper() Brian Gerst
2023-07-10 8:13 ` [tip: x86/urgent] " tip-bot2 for Brian Gerst
2023-06-23 22:55 ` [PATCH v2 2/2] x86: Rewrite ret_from_fork() in C Brian Gerst
2023-07-10 8:13 ` [tip: x86/urgent] " tip-bot2 for Brian Gerst
2023-07-19 15:21 ` [PATCH v2 2/2] " Petr Mladek
2023-07-19 20:02 ` Peter Zijlstra
2023-07-19 20:15 ` Peter Zijlstra
2023-07-19 20:50 ` Peter Zijlstra
2023-07-19 23:31 ` Josh Poimboeuf
2023-07-20 5:22 ` Peter Zijlstra
2023-07-20 9:28 ` Peter Zijlstra
2023-07-20 8:18 ` Petr Mladek
2023-07-21 9:20 ` [tip: x86/urgent] x86: Fix kthread unwind tip-bot2 for Peter Zijlstra
2023-07-19 20:33 ` [PATCH v2 2/2] x86: Rewrite ret_from_fork() in C Joe Lawrence
2023-07-19 20:41 ` Peter Zijlstra
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