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x86/asm/entry: Untangle 'ia32_sysenter_target' into two entry points: entry_SYSENTER_32 and entry_SYSENTER_compat

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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 <luto@amacapital.net>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar 2015-06-08 08:33:56 +02:00
parent 2cd23553b4
commit 4c8cd0c50d
5 changed files with 12 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
arch/x86/entry/entry_32.S
View File

@ -307,7 +307,7 @@ END(resume_kernel)
the vsyscall page. See vsyscall-sysentry.S, which defines the symbol. */ the vsyscall page. See vsyscall-sysentry.S, which defines the symbol. */
# sysenter call handler stub # sysenter call handler stub
ENTRY(ia32_sysenter_target) ENTRY(entry_SYSENTER_32)
movl TSS_sysenter_sp0(%esp),%esp movl TSS_sysenter_sp0(%esp),%esp
sysenter_past_esp: sysenter_past_esp:
/* /*
@ -412,7 +412,7 @@ sysexit_audit:
.popsection .popsection
_ASM_EXTABLE(1b,2b) _ASM_EXTABLE(1b,2b)
PTGS_TO_GS_EX PTGS_TO_GS_EX
ENDPROC(ia32_sysenter_target) ENDPROC(entry_SYSENTER_32)
# system call handler stub # system call handler stub
ENTRY(system_call) ENTRY(system_call)
@ -1135,7 +1135,7 @@ END(page_fault)
ENTRY(debug) ENTRY(debug)
ASM_CLAC ASM_CLAC
cmpl $ia32_sysenter_target,(%esp) cmpl $entry_SYSENTER_32,(%esp)
jne debug_stack_correct jne debug_stack_correct
FIX_STACK 12, debug_stack_correct, debug_esp_fix_insn FIX_STACK 12, debug_stack_correct, debug_esp_fix_insn
debug_stack_correct: debug_stack_correct:
@ -1165,7 +1165,7 @@ ENTRY(nmi)
popl %eax popl %eax
je nmi_espfix_stack je nmi_espfix_stack
#endif #endif
cmpl $ia32_sysenter_target,(%esp) cmpl $entry_SYSENTER_32,(%esp)
je nmi_stack_fixup je nmi_stack_fixup
pushl %eax pushl %eax
movl %esp,%eax movl %esp,%eax
@ -1176,7 +1176,7 @@ ENTRY(nmi)
cmpl $(THREAD_SIZE-20),%eax cmpl $(THREAD_SIZE-20),%eax
popl %eax popl %eax
jae nmi_stack_correct jae nmi_stack_correct
cmpl $ia32_sysenter_target,12(%esp) cmpl $entry_SYSENTER_32,12(%esp)
je nmi_debug_stack_check je nmi_debug_stack_check
nmi_stack_correct: nmi_stack_correct:
pushl %eax pushl %eax

4
arch/x86/entry/entry_64_compat.S
View File

@ -57,7 +57,7 @@ ENDPROC(native_usergs_sysret32)
* path below. We set up a complete hardware stack frame to share code * path below. We set up a complete hardware stack frame to share code
* with the int 0x80 path. * with the int 0x80 path.
*/ */
ENTRY(ia32_sysenter_target) ENTRY(entry_SYSENTER_compat)
/* /*
* Interrupts are off on entry. * Interrupts are off on entry.
* We do not frame this tiny irq-off block with TRACE_IRQS_OFF/ON, * We do not frame this tiny irq-off block with TRACE_IRQS_OFF/ON,
@ -256,7 +256,7 @@ sysenter_tracesys:
RESTORE_EXTRA_REGS RESTORE_EXTRA_REGS
jmp sysenter_do_call jmp sysenter_do_call
ENDPROC(ia32_sysenter_target) ENDPROC(entry_SYSENTER_compat)
/* /*
* 32-bit SYSCALL instruction entry. * 32-bit SYSCALL instruction entry.

3
arch/x86/include/asm/proto.h
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@ -10,7 +10,8 @@ void syscall_init(void);
void entry_INT80_compat(void); void entry_INT80_compat(void);
void entry_SYSCALL_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_configure_nx(void);
void x86_report_nx(void); void x86_report_nx(void);

4
arch/x86/kernel/cpu/common.c
View File

@ -1026,7 +1026,7 @@ void enable_sep_cpu(void)
(unsigned long)tss + offsetofend(struct tss_struct, SYSENTER_stack), (unsigned long)tss + offsetofend(struct tss_struct, SYSENTER_stack),
0); 0);
wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)ia32_sysenter_target, 0); wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0);
out: out:
put_cpu(); put_cpu();
@ -1216,7 +1216,7 @@ void syscall_init(void)
*/ */
wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS); wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL); 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 #else
wrmsrl(MSR_CSTAR, ignore_sysret); wrmsrl(MSR_CSTAR, ignore_sysret);
wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)GDT_ENTRY_INVALID_SEG); wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)GDT_ENTRY_INVALID_SEG);

2
arch/x86/xen/xen-asm_64.S
View File

@ -128,7 +128,7 @@ ENDPROC(xen_syscall32_target)
/* 32-bit compat sysenter target */ /* 32-bit compat sysenter target */
ENTRY(xen_sysenter_target) ENTRY(xen_sysenter_target)
undo_xen_syscall undo_xen_syscall
jmp ia32_sysenter_target jmp entry_SYSENTER_compat
ENDPROC(xen_sysenter_target) ENDPROC(xen_sysenter_target)
#else /* !CONFIG_IA32_EMULATION */ #else /* !CONFIG_IA32_EMULATION */