Messages in this thread Patch in this message | | | Date | Fri, 8 May 2015 06:30:21 -0700 | From | tip-bot for Denys Vlasenko <> | Subject | [tip:x86/asm] x86/entry: Stop using PER_CPU_VAR(kernel_stack) |
| |
Commit-ID: 63332a8455d8310b77d38779c6c21a660a8d9feb Gitweb: http://git.kernel.org/tip/63332a8455d8310b77d38779c6c21a660a8d9feb Author: Denys Vlasenko <dvlasenk@redhat.com> AuthorDate: Fri, 24 Apr 2015 17:31:33 +0200 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Fri, 8 May 2015 13:43:52 +0200
x86/entry: Stop using PER_CPU_VAR(kernel_stack)
PER_CPU_VAR(kernel_stack) is redundant:
- On the 64-bit build, we can use PER_CPU_VAR(cpu_tss + TSS_sp0). - On the 32-bit build, we can use PER_CPU_VAR(cpu_current_top_of_stack).
PER_CPU_VAR(kernel_stack) will be deleted by a separate change.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1429889495-27850-1-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/ia32/ia32entry.S | 2 +- arch/x86/include/asm/thread_info.h | 8 +++++++- arch/x86/kernel/entry_64.S | 2 +- arch/x86/xen/xen-asm_64.S | 5 +++-- 4 files changed, 12 insertions(+), 5 deletions(-)
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index 2ab0f71..1b1330c 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -346,7 +346,7 @@ ENTRY(ia32_cstar_target) SWAPGS_UNSAFE_STACK movl %esp,%r8d CFI_REGISTER rsp,r8 - movq PER_CPU_VAR(kernel_stack),%rsp + movq PER_CPU_VAR(cpu_tss + TSS_sp0),%rsp ENABLE_INTERRUPTS(CLBR_NONE) /* Zero-extending 32-bit regs, do not remove */ diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index b4bdec3..d656a36 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -198,9 +198,15 @@ static inline unsigned long current_stack_pointer(void) #else /* !__ASSEMBLY__ */ /* Load thread_info address into "reg" */ +#ifdef CONFIG_X86_32 #define GET_THREAD_INFO(reg) \ - _ASM_MOV PER_CPU_VAR(kernel_stack),reg ; \ + _ASM_MOV PER_CPU_VAR(cpu_current_top_of_stack),reg ; \ _ASM_SUB $(THREAD_SIZE),reg ; +#else +#define GET_THREAD_INFO(reg) \ + _ASM_MOV PER_CPU_VAR(cpu_tss + TSS_sp0),reg ; \ + _ASM_SUB $(THREAD_SIZE),reg ; +#endif /* * ASM operand which evaluates to a 'thread_info' address of diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 7423e3e..c13b86b 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -216,7 +216,7 @@ ENTRY(system_call) GLOBAL(system_call_after_swapgs) movq %rsp,PER_CPU_VAR(rsp_scratch) - movq PER_CPU_VAR(kernel_stack),%rsp + movq PER_CPU_VAR(cpu_tss + TSS_sp0),%rsp /* Construct struct pt_regs on stack */ pushq_cfi $__USER_DS /* pt_regs->ss */ diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S index a2cabb8..5aa7ec6 100644 --- a/arch/x86/xen/xen-asm_64.S +++ b/arch/x86/xen/xen-asm_64.S @@ -15,6 +15,7 @@ #include <asm/percpu.h> #include <asm/processor-flags.h> #include <asm/segment.h> +#include <asm/asm-offsets.h> #include <xen/interface/xen.h> @@ -53,7 +54,7 @@ ENTRY(xen_sysret64) * still with the kernel gs, so we can easily switch back */ movq %rsp, PER_CPU_VAR(rsp_scratch) - movq PER_CPU_VAR(kernel_stack), %rsp + movq PER_CPU_VAR(cpu_tss + TSS_sp0), %rsp pushq $__USER_DS pushq PER_CPU_VAR(rsp_scratch) @@ -72,7 +73,7 @@ ENTRY(xen_sysret32) * still with the kernel gs, so we can easily switch back */ movq %rsp, PER_CPU_VAR(rsp_scratch) - movq PER_CPU_VAR(kernel_stack), %rsp + movq PER_CPU_VAR(cpu_tss + TSS_sp0), %rsp pushq $__USER32_DS pushq PER_CPU_VAR(rsp_scratch)
| |