diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2020-05-29 23:27:38 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 15:15:23 +0200 |
| commit | fd501d4f0399700011acde486576c7c1eb8e7a61 (patch) | |
| tree | 8c5c09d3cb0b5aa0f249c6627dc4298354f21442 /arch/x86/include/asm/cpu_entry_area.h | |
| parent | f9912ada82862df341b3e86864cbd532d0d24b84 (diff) | |
x86/entry: Remove DBn stacks
Both #DB itself, as all other IST users (NMI, #MC) now clear DR7 on
entry. Combined with not allowing breakpoints on entry/noinstr/NOKPROBE
text and no single step (EFLAGS.TF) inside the #DB handler should guarantee
no nested #DB.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200529213321.303027161@infradead.org
Diffstat (limited to 'arch/x86/include/asm/cpu_entry_area.h')
| -rw-r--r-- | arch/x86/include/asm/cpu_entry_area.h | 12 |
1 files changed, 3 insertions, 9 deletions
diff --git a/arch/x86/include/asm/cpu_entry_area.h b/arch/x86/include/asm/cpu_entry_area.h index 02c0078d3787..8902fdb7de13 100644 --- a/arch/x86/include/asm/cpu_entry_area.h +++ b/arch/x86/include/asm/cpu_entry_area.h @@ -11,15 +11,11 @@ #ifdef CONFIG_X86_64 /* Macro to enforce the same ordering and stack sizes */ -#define ESTACKS_MEMBERS(guardsize, db2_holesize)\ +#define ESTACKS_MEMBERS(guardsize) \ char DF_stack_guard[guardsize]; \ char DF_stack[EXCEPTION_STKSZ]; \ char NMI_stack_guard[guardsize]; \ char NMI_stack[EXCEPTION_STKSZ]; \ - char DB2_stack_guard[guardsize]; \ - char DB2_stack[db2_holesize]; \ - char DB1_stack_guard[guardsize]; \ - char DB1_stack[EXCEPTION_STKSZ]; \ char DB_stack_guard[guardsize]; \ char DB_stack[EXCEPTION_STKSZ]; \ char MCE_stack_guard[guardsize]; \ @@ -28,12 +24,12 @@ /* The exception stacks' physical storage. No guard pages required */ struct exception_stacks { - ESTACKS_MEMBERS(0, 0) + ESTACKS_MEMBERS(0) }; /* The effective cpu entry area mapping with guard pages. */ struct cea_exception_stacks { - ESTACKS_MEMBERS(PAGE_SIZE, EXCEPTION_STKSZ) + ESTACKS_MEMBERS(PAGE_SIZE) }; /* @@ -42,8 +38,6 @@ struct cea_exception_stacks { enum exception_stack_ordering { ESTACK_DF, ESTACK_NMI, - ESTACK_DB2, - ESTACK_DB1, ESTACK_DB, ESTACK_MCE, N_EXCEPTION_STACKS |