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authorAndy Lutomirski <luto@kernel.org>2020-06-11 20:26:38 -0700
committerThomas Gleixner <tglx@linutronix.de>2020-06-12 12:12:57 +0200
commit15a416e8aaa758b5534f64a3972dae05275bc225 (patch)
treee4ae9ce3068dbd6df81a2a445be81e015a387aa5 /arch/x86/include
parentf0178fc01fe46bab6a95415f5647d1a74efcad1b (diff)
downloadlinux-15a416e8aaa758b5534f64a3972dae05275bc225.tar.gz
x86/entry: Treat BUG/WARN as NMI-like entries
BUG/WARN are cleverly optimized using UD2 to handle the BUG/WARN out of line in an exception fixup. But if BUG or WARN is issued in a funny RCU context, then the idtentry_enter...() path might helpfully WARN that the RCU context is invalid, which results in infinite recursion. Split the BUG/WARN handling into an nmi_enter()/nmi_exit() path in exc_invalid_op() to increase the chance to survive the experience. [ tglx: Make the declaration match the implementation ] Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/f8fe40e0088749734b4435b554f73eee53dcf7a8.1591932307.git.luto@kernel.org
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/idtentry.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index d203c541a65a..2fc6b0c58341 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -543,7 +543,6 @@ SYM_CODE_END(spurious_entries_start)
DECLARE_IDTENTRY(X86_TRAP_DE, exc_divide_error);
DECLARE_IDTENTRY(X86_TRAP_OF, exc_overflow);
DECLARE_IDTENTRY(X86_TRAP_BR, exc_bounds);
-DECLARE_IDTENTRY(X86_TRAP_UD, exc_invalid_op);
DECLARE_IDTENTRY(X86_TRAP_NM, exc_device_not_available);
DECLARE_IDTENTRY(X86_TRAP_OLD_MF, exc_coproc_segment_overrun);
DECLARE_IDTENTRY(X86_TRAP_SPURIOUS, exc_spurious_interrupt_bug);
@@ -561,6 +560,7 @@ DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_GP, exc_general_protection);
DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_AC, exc_alignment_check);
/* Raw exception entries which need extra work */
+DECLARE_IDTENTRY_RAW(X86_TRAP_UD, exc_invalid_op);
DECLARE_IDTENTRY_RAW(X86_TRAP_BP, exc_int3);
DECLARE_IDTENTRY_RAW_ERRORCODE(X86_TRAP_PF, exc_page_fault);