linux-kernel - [patch 00/10] x86/fpu: Clean up error handling in sigframe related code

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Message-ID: <20210830154702.247681585@linutronix.de>
Date:   Mon, 30 Aug 2021 18:27:21 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     x86@...nel.org, Al Viro <viro@...iv.linux.org.uk>,
        Linus Torvalds <torvalds@...ux-foundation.org>
Subject: [patch 00/10] x86/fpu: Clean up error handling in sigframe related code

A recent discussion [1] about hardware poisoning unearthed some short
comings in the error handling of the sigframe related FPU code:

  - The error exit for exceptions other than #PF is obfuscated

  - The error code return values of the various functions are pointless
    because all callers just care about success or failure and the error
    codes are never propagated to user space.

  - Some of the buffer clearing happens needlessly inside of page fault
    disabled regions.

The following series cleans this up. As a side effect the resulting text
size of fpu/signal.o shrinks by about 150 bytes.

It's also available in git:

    git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git x86/fpu

Thanks,

	tglx

[1] https://lore.kernel.org/r/87r1edgs2w.ffs@tglx

---
 ia32/ia32_signal.c         |   14 ++--
 include/asm/fpu/internal.h |   21 ++----
 kernel/fpu/signal.c        |  145 +++++++++++++++++++++++----------------------
 kernel/signal.c            |   18 ++---
 4 files changed, 98 insertions(+), 100 deletions(-)