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authorAndy Lutomirski <luto@kernel.org>2019-11-20 22:12:38 -0800
committerIngo Molnar <mingo@kernel.org>2019-11-26 21:53:34 +0100
commit93efbde2c331004d8053f04b4bf0ca3e630b474a (patch)
treeda94642f314fb062e92a555eca60d8d072e98ae7 /arch/x86
parentb09511c253e5c739a60952b97c071a93e92b2e88 (diff)
x86/traps: Disentangle the 32-bit and 64-bit doublefault code
The 64-bit doublefault handler is much nicer than the 32-bit one. As a first step toward unifying them, make the 64-bit handler self-contained. This should have no effect no functional effect except in the odd case of x86_64 with CONFIG_DOUBLEFAULT=n in which case it will change the logging a bit. This also gets rid of CONFIG_DOUBLEFAULT configurability on 64-bit kernels. It didn't do anything useful -- CONFIG_DOUBLEFAULT=n didn't actually disable doublefault handling on x86_64. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/Kconfig.debug2
-rw-r--r--arch/x86/include/asm/processor.h1
-rw-r--r--arch/x86/kernel/doublefault.c11
-rw-r--r--arch/x86/kernel/traps.c12
4 files changed, 4 insertions, 22 deletions
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 409c00f74e60..c4eab8ed33a3 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -117,7 +117,7 @@ config DEBUG_WX
config DOUBLEFAULT
default y
- bool "Enable doublefault exception handler" if EXPERT
+ bool "Enable doublefault exception handler" if EXPERT && X86_32
---help---
This option allows trapping of rare doublefault exceptions that
would otherwise cause a system to silently reboot. Disabling this
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index e51afbb0cbfb..f6c630097d9f 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -997,7 +997,6 @@ bool xen_set_default_idle(void);
#endif
void stop_this_cpu(void *dummy);
-void df_debug(struct pt_regs *regs, long error_code);
void microcode_check(void);
enum l1tf_mitigations {
diff --git a/arch/x86/kernel/doublefault.c b/arch/x86/kernel/doublefault.c
index 0d6c657593f8..0b3c616b61a3 100644
--- a/arch/x86/kernel/doublefault.c
+++ b/arch/x86/kernel/doublefault.c
@@ -72,15 +72,4 @@ struct x86_hw_tss doublefault_tss __cacheline_aligned = {
.__cr3 = __pa_nodebug(swapper_pg_dir),
};
-/* dummy for do_double_fault() call */
-void df_debug(struct pt_regs *regs, long error_code) {}
-
-#else /* !CONFIG_X86_32 */
-
-void df_debug(struct pt_regs *regs, long error_code)
-{
- pr_emerg("PANIC: double fault, error_code: 0x%lx\n", error_code);
- show_regs(regs);
- panic("Machine halted.");
-}
#endif
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index c90312146da0..76381b04dc93 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -411,15 +411,9 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsign
handle_stack_overflow("kernel stack overflow (double-fault)", regs, cr2);
#endif
-#ifdef CONFIG_DOUBLEFAULT
- df_debug(regs, error_code);
-#endif
- /*
- * This is always a kernel trap and never fixable (and thus must
- * never return).
- */
- for (;;)
- die(str, regs, error_code);
+ pr_emerg("PANIC: double fault, error_code: 0x%lx\n", error_code);
+ show_regs(regs);
+ panic("Machine halted.");
}
#endif