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authorBrian Gerst <brgerst@gmail.com>2016-08-13 12:38:19 -0400
committerIngo Molnar <mingo@kernel.org>2016-08-24 12:31:41 +0200
commit0100301bfdf56a2a370c7157b5ab0fbf9313e1cd (patch)
treef8a339f20fb486a1ebe029d1c409e94c9bf8d67a /arch/x86/kernel/asm-offsets.c
parentsched/x86: Add 'struct inactive_task_frame' to better document the sleeping task stack frame (diff)
downloadlinux-dev-0100301bfdf56a2a370c7157b5ab0fbf9313e1cd.tar.xz
linux-dev-0100301bfdf56a2a370c7157b5ab0fbf9313e1cd.zip
sched/x86: Rewrite the switch_to() code
Move the low-level context switch code to an out-of-line asm stub instead of using complex inline asm. This allows constructing a new stack frame for the child process to make it seamlessly flow to ret_from_fork without an extra test and branch in __switch_to(). It also improves code generation for __schedule() by using the C calling convention instead of clobbering all registers. Signed-off-by: Brian Gerst <brgerst@gmail.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1471106302-10159-5-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/asm-offsets.c')
-rw-r--r--arch/x86/kernel/asm-offsets.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index 2bd5c6ff7ee7..db3a0af9b9ec 100644
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -29,6 +29,12 @@
void common(void) {
BLANK();
+ OFFSET(TASK_threadsp, task_struct, thread.sp);
+#ifdef CONFIG_CC_STACKPROTECTOR
+ OFFSET(TASK_stack_canary, task_struct, stack_canary);
+#endif
+
+ BLANK();
OFFSET(TI_flags, thread_info, flags);
OFFSET(TI_status, thread_info, status);