From 5ed386ec09a5d75bcf073967e55e895c2607a5c3 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 6 Apr 2017 16:19:22 +0200 Subject: [PATCH] x86/mpx: Correctly report do_mpx_bt_fault() failures to user-space When this function fails it just sends a SIGSEGV signal to user-space using force_sig(). This signal is missing essential information about the cause, e.g. the trap_nr or an error code. Fix this by propagating the error to the only caller of mpx_handle_bd_fault(), do_bounds(), which sends the correct SIGSEGV signal to the process. Signed-off-by: Joerg Roedel Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Fixes: fe3d197f84319 ('x86, mpx: On-demand kernel allocation of bounds tables') Link: http://lkml.kernel.org/r/1491488362-27198-1-git-send-email-joro@8bytes.org Signed-off-by: Ingo Molnar --- arch/x86/mm/mpx.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c index cd44ae727df7..1c34b767c84c 100644 --- a/arch/x86/mm/mpx.c +++ b/arch/x86/mm/mpx.c @@ -526,15 +526,7 @@ int mpx_handle_bd_fault(void) if (!kernel_managing_mpx_tables(current->mm)) return -EINVAL; - if (do_mpx_bt_fault()) { - force_sig(SIGSEGV, current); - /* - * The force_sig() is essentially "handling" this - * exception, so we do not pass up the error - * from do_mpx_bt_fault(). - */ - } - return 0; + return do_mpx_bt_fault(); } /*