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authorThomas Gleixner <tglx@linutronix.de>2018-01-18 16:28:26 +0100
committerThomas Gleixner <tglx@linutronix.de>2018-01-19 16:31:28 +0100
commit6f41c34d69eb005e7848716bbcafc979b35037d5 (patch)
treeb5f5f6275ac19cc185a127c2f8a913f46019d705 /arch
parent6cfb521ac0d5b97470883ff9b7facae264b7ab12 (diff)
x86/mce: Make machine check speculation protected
The machine check idtentry uses an indirect branch directly from the low level code. This evades the speculation protection. Replace it by a direct call into C code and issue the indirect call there so the compiler can apply the proper speculation protection. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by:Borislav Petkov <bp@alien8.de> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Niced-by: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801181626290.1847@nanos
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/entry/entry_64.S2
-rw-r--r--arch/x86/include/asm/traps.h1
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce.c5
3 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index d54a0ede61d1..63f4320602a3 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1258,7 +1258,7 @@ idtentry async_page_fault do_async_page_fault has_error_code=1
#endif
#ifdef CONFIG_X86_MCE
-idtentry machine_check has_error_code=0 paranoid=1 do_sym=*machine_check_vector(%rip)
+idtentry machine_check do_mce has_error_code=0 paranoid=1
#endif
/*
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 31051f35cbb7..3de69330e6c5 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -88,6 +88,7 @@ dotraplinkage void do_simd_coprocessor_error(struct pt_regs *, long);
#ifdef CONFIG_X86_32
dotraplinkage void do_iret_error(struct pt_regs *, long);
#endif
+dotraplinkage void do_mce(struct pt_regs *, long);
static inline int get_si_code(unsigned long condition)
{
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 3b413065c613..a9e898b71208 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -1788,6 +1788,11 @@ static void unexpected_machine_check(struct pt_regs *regs, long error_code)
void (*machine_check_vector)(struct pt_regs *, long error_code) =
unexpected_machine_check;
+dotraplinkage void do_mce(struct pt_regs *regs, long error_code)
+{
+ machine_check_vector(regs, error_code);
+}
+
/*
* Called for each booted CPU to set up machine checks.
* Must be called with preempt off: