Commit-ID: 6f41c34d69eb005e7848716bbcafc979b35037d5
Gitweb: https://git.kernel.org/tip/6f41c34d69eb005e7848716bbcafc979b35037d5
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Thu, 18 Jan 2018 16:28:26 +0100
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 19 Jan 2018 16:31:28 +0100
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@xxxxxxxxxxxxx>
Reviewed-by:Borislav Petkov <bp@xxxxxxxxx>
Reviewed-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Niced-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801181626290.1847@nanos
---
arch/x86/entry/entry_64.S | 2 +-
arch/x86/include/asm/traps.h | 1 +
arch/x86/kernel/cpu/mcheck/mce.c | 5 +++++
3 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index d54a0ed..63f4320 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 31051f3..3de6933 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 3b413065..a9e898b 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:
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|