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Commit 4c8cd0c5 authored by Ingo Molnar's avatar Ingo Molnar
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x86/asm/entry: Untangle 'ia32_sysenter_target' into two entry points:... 


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 <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: default avatarIngo Molnar <mingo@kernel.org>
parent 2cd23553

arch/x86/entry/entry_32.S

+5 −5
Original line number Original line Diff line number Diff line
@@ -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

arch/x86/entry/entry_64_compat.S

+2 −2
Original line number Original line Diff line number Diff line
@@ -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.

arch/x86/include/asm/proto.h

+2 −1
Original line number Original line Diff line number Diff line
@@ -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);

arch/x86/kernel/cpu/common.c

+2 −2
Original line number Original line Diff line number Diff line
@@ -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);

arch/x86/xen/xen-asm_64.S

+1 −1
Original line number Original line Diff line number Diff line
@@ -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 */