The patch titled Subject: fs/signalfd.c: fix inconsistent return codes for signalfd4 has been added to the -mm tree. Its filename is fs-signalfdc-fix-inconsistent-return-codes-for-signalfd4.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/fs-signalfdc-fix-inconsistent-return-codes-for-signalfd4.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/fs-signalfdc-fix-inconsistent-return-codes-for-signalfd4.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Helge Deller <deller@xxxxxx> Subject: 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. Link: http://lkml.kernel.org/r/20200530100707.GA10159@xxxxxxxxxxxxxxxx Signed-off-by: Helge Deller <deller@xxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Laurent Vivier <laurent@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/signalfd.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/fs/signalfd.c~fs-signalfdc-fix-inconsistent-return-codes-for-signalfd4 +++ a/fs/signalfd.c @@ -314,9 +314,10 @@ SYSCALL_DEFINE4(signalfd4, int, ufd, sig { 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, sigs { 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); } _ Patches currently in -mm which might be from deller@xxxxxx are fs-signalfdc-fix-inconsistent-return-codes-for-signalfd4.patch