diff options
| author | Andy Lutomirski <luto@kernel.org> | 2017-07-11 10:33:38 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-07-18 10:56:22 +0200 |
| commit | 1d3e53e8624a3ec85f4041ca6d973da7c1575938 (patch) | |
| tree | b8e2bb366529b5eb91c54cbd15bf437c8434dd0a /arch/x86/kernel/process_64.c | |
| parent | cb8c65ccff7f77d0285f1b126c72d37b2572c865 (diff) | |
x86/entry/64: Refactor IRQ stacks and make them NMI-safe
This will allow IRQ stacks to nest inside NMIs or similar entries
that can happen during IRQ stack setup or teardown.
The new macros won't work correctly if they're invoked with IRQs on.
Add a check under CONFIG_DEBUG_ENTRY to detect that.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
[ Use %r10 instead of %r11 in xen_do_hypervisor_callback to make objtool
and ORC unwinder's lives a little easier. ]
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/b0b2ff5fb97d2da2e1d7e1f380190c92545c8bb5.1499786555.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/process_64.c')
| -rw-r--r-- | arch/x86/kernel/process_64.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index c3169be4c596..2987e3991c2b 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -279,6 +279,9 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) struct tss_struct *tss = &per_cpu(cpu_tss, cpu); unsigned prev_fsindex, prev_gsindex; + WARN_ON_ONCE(IS_ENABLED(CONFIG_DEBUG_ENTRY) && + this_cpu_read(irq_count) != -1); + switch_fpu_prepare(prev_fpu, cpu); /* We must save %fs and %gs before load_TLS() because |