From 4c8cd0c50d0b1559727bf0ec7ff27caeba2dfe09 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 8 Jun 2015 08:33:56 +0200 Subject: [PATCH] x86/asm/entry: Untangle 'ia32_sysenter_target' into two entry points: entry_SYSENTER_32 and entry_SYSENTER_compat So the SYSENTER instruction is pretty quirky and it has different behavior depending on bitness and CPU maker. Yet we create a false sense of coherency by naming it 'ia32_sysenter_target' in both of the cases. Split the name into its two uses: ia32_sysenter_target (32) -> entry_SYSENTER_32 ia32_sysenter_target (64) -> entry_SYSENTER_compat As per the generic naming scheme for x86 system call entry points: entry_MNEMONIC_qualifier where 'qualifier' is one of _32, _64 or _compat. Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- arch/x86/entry/entry_32.S | 10 +++++----- arch/x86/entry/entry_64_compat.S | 4 ++-- arch/x86/include/asm/proto.h | 3 ++- arch/x86/kernel/cpu/common.c | 4 ++-- arch/x86/xen/xen-asm_64.S | 2 +- 5 files changed, 12 insertions(+), 11 deletions(-) diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 0ac73de..a65f46c 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -307,7 +307,7 @@ END(resume_kernel) the vsyscall page. See vsyscall-sysentry.S, which defines the symbol. */ # sysenter call handler stub -ENTRY(ia32_sysenter_target) +ENTRY(entry_SYSENTER_32) movl TSS_sysenter_sp0(%esp),%esp sysenter_past_esp: /* @@ -412,7 +412,7 @@ sysexit_audit: .popsection _ASM_EXTABLE(1b,2b) PTGS_TO_GS_EX -ENDPROC(ia32_sysenter_target) +ENDPROC(entry_SYSENTER_32) # system call handler stub ENTRY(system_call) @@ -1135,7 +1135,7 @@ END(page_fault) ENTRY(debug) ASM_CLAC - cmpl $ia32_sysenter_target,(%esp) + cmpl $entry_SYSENTER_32,(%esp) jne debug_stack_correct FIX_STACK 12, debug_stack_correct, debug_esp_fix_insn debug_stack_correct: @@ -1165,7 +1165,7 @@ ENTRY(nmi) popl %eax je nmi_espfix_stack #endif - cmpl $ia32_sysenter_target,(%esp) + cmpl $entry_SYSENTER_32,(%esp) je nmi_stack_fixup pushl %eax movl %esp,%eax @@ -1176,7 +1176,7 @@ ENTRY(nmi) cmpl $(THREAD_SIZE-20),%eax popl %eax jae nmi_stack_correct - cmpl $ia32_sysenter_target,12(%esp) + cmpl $entry_SYSENTER_32,12(%esp) je nmi_debug_stack_check nmi_stack_correct: pushl %eax diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index 8058892..59840e3 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -57,7 +57,7 @@ ENDPROC(native_usergs_sysret32) * path below. We set up a complete hardware stack frame to share code * with the int 0x80 path. */ -ENTRY(ia32_sysenter_target) +ENTRY(entry_SYSENTER_compat) /* * Interrupts are off on entry. * We do not frame this tiny irq-off block with TRACE_IRQS_OFF/ON, @@ -256,7 +256,7 @@ sysenter_tracesys: RESTORE_EXTRA_REGS jmp sysenter_do_call -ENDPROC(ia32_sysenter_target) +ENDPROC(entry_SYSENTER_compat) /* * 32-bit SYSCALL instruction entry. diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h index 7d2961a..83a7f82 100644 --- a/arch/x86/include/asm/proto.h +++ b/arch/x86/include/asm/proto.h @@ -10,7 +10,8 @@ void syscall_init(void); void entry_INT80_compat(void); void entry_SYSCALL_compat(void); -void ia32_sysenter_target(void); +void entry_SYSENTER_32(void); +void entry_SYSENTER_compat(void); void x86_configure_nx(void); void x86_report_nx(void); diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index f0b85c4..b2ae7ce 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1026,7 +1026,7 @@ void enable_sep_cpu(void) (unsigned long)tss + offsetofend(struct tss_struct, SYSENTER_stack), 0); - wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)ia32_sysenter_target, 0); + wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0); out: put_cpu(); @@ -1216,7 +1216,7 @@ void syscall_init(void) */ wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS); wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL); - wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target); + wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat); #else wrmsrl(MSR_CSTAR, ignore_sysret); wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)GDT_ENTRY_INVALID_SEG); diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S index 3c43c03..ccac1b1 100644 --- a/arch/x86/xen/xen-asm_64.S +++ b/arch/x86/xen/xen-asm_64.S @@ -128,7 +128,7 @@ ENDPROC(xen_syscall32_target) /* 32-bit compat sysenter target */ ENTRY(xen_sysenter_target) undo_xen_syscall - jmp ia32_sysenter_target + jmp entry_SYSENTER_compat ENDPROC(xen_sysenter_target) #else /* !CONFIG_IA32_EMULATION */ -- 2.7.4