Commit a089e3fd authored Aug 11, 2020 by Helge Deller Committed by Linus Torvalds Aug 12, 2020

fs/signalfd.c: fix inconsistent return codes for signalfd4



The kernel signalfd4() syscall returns different error codes when called
either in compat or native mode.  This behaviour makes correct emulation
in qemu and testing programs like LTP more complicated.

Fix the code to always return -in both modes- EFAULT for unaccessible user
memory, and EINVAL when called with an invalid signal mask.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Laurent Vivier <laurent@vivier.eu>
Link: http://lkml.kernel.org/r/20200530100707.GA10159@ls3530.fritz.box


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent a090a5a7

fs/signalfd.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -314,9 +314,10 @@ SYSCALL_DEFINE4(signalfd4, int, ufd, sigset_t __user *, user_mask,
		{
		sigset_t mask;

		if (sizemask != sizeof(sigset_t) \|\|
		copy_from_user(&mask, user_mask, sizeof(mask)))
		if (sizemask != sizeof(sigset_t))
		return -EINVAL;
		if (copy_from_user(&mask, user_mask, sizeof(mask)))
		return -EFAULT;
		return do_signalfd4(ufd, &mask, flags);
		}

		@@ -325,9 +326,10 @@ SYSCALL_DEFINE3(signalfd, int, ufd, sigset_t __user *, user_mask,
		{
		sigset_t mask;

		if (sizemask != sizeof(sigset_t) \|\|
		copy_from_user(&mask, user_mask, sizeof(mask)))
		if (sizemask != sizeof(sigset_t))
		return -EINVAL;
		if (copy_from_user(&mask, user_mask, sizeof(mask)))
		return -EFAULT;
		return do_signalfd4(ufd, &mask, 0);
		}

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