Commit 1b00255f authored by Josh Poimboeuf's avatar Josh Poimboeuf Committed by Ingo Molnar
Browse files

x86/entry/32, x86/boot/32: Use local labels 



Add the local label prefix to all non-function named labels in head_32.S
and entry_32.S.  In addition to decluttering the symbol table, it also
will help stack traces to be more sensible.  For example, the last
reported function in the idle task stack trace will be startup_32_smp()
instead of is486().

Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
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: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/14f9f7afd478b23a762f40734da1a57c0c273f6e.1474480779.git.jpoimboe@redhat.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 59df2268

arch/x86/entry/entry_32.S

+22 −21
Original line number Diff line number Diff line
@@ -307,13 +307,13 @@ END(ret_from_exception) 
#ifdef CONFIG_PREEMPT

ENTRY(resume_kernel)

	DISABLE_INTERRUPTS(CLBR_ANY)

need_resched:

.Lneed_resched:

	cmpl	$0, PER_CPU_VAR(__preempt_count)

	jnz	restore_all

	testl	$X86_EFLAGS_IF, PT_EFLAGS(%esp)	# interrupts off (exception path) ?

	jz	restore_all

	call	preempt_schedule_irq

	jmp	need_resched

	jmp	.Lneed_resched

END(resume_kernel)

#endif
@@ -334,7 +334,7 @@ GLOBAL(__begin_SYSENTER_singlestep_region) 
 */

ENTRY(xen_sysenter_target)

	addl	$5*4, %esp			/* remove xen-provided frame */

	jmp	sysenter_past_esp

	jmp	.Lsysenter_past_esp

#endif



/*
@@ -371,7 +371,7 @@ ENTRY(xen_sysenter_target) 
 */

ENTRY(entry_SYSENTER_32)

	movl	TSS_sysenter_sp0(%esp), %esp

sysenter_past_esp:

.Lsysenter_past_esp:

	pushl	$__USER_DS		/* pt_regs->ss */

	pushl	%ebp			/* pt_regs->sp (stashed in bp) */

	pushfl				/* pt_regs->flags (except IF = 0) */
@@ -504,9 +504,9 @@ ENTRY(entry_INT80_32) 


restore_all:

	TRACE_IRQS_IRET

restore_all_notrace:

.Lrestore_all_notrace:

#ifdef CONFIG_X86_ESPFIX32

	ALTERNATIVE	"jmp restore_nocheck", "", X86_BUG_ESPFIX

	ALTERNATIVE	"jmp .Lrestore_nocheck", "", X86_BUG_ESPFIX



	movl	PT_EFLAGS(%esp), %eax		# mix EFLAGS, SS and CS

	/*
@@ -518,22 +518,23 @@ restore_all_notrace: 
	movb	PT_CS(%esp), %al

	andl	$(X86_EFLAGS_VM | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax

	cmpl	$((SEGMENT_LDT << 8) | USER_RPL), %eax

	je ldt_ss				# returning to user-space with LDT SS

	je .Lldt_ss				# returning to user-space with LDT SS

#endif

restore_nocheck:

.Lrestore_nocheck:

	RESTORE_REGS 4				# skip orig_eax/error_code

irq_return:

.Lirq_return:

	INTERRUPT_RETURN



.section .fixup, "ax"

ENTRY(iret_exc	)

	pushl	$0				# no error code

	pushl	$do_iret_error

	jmp	error_code

.previous

	_ASM_EXTABLE(irq_return, iret_exc)

	_ASM_EXTABLE(.Lirq_return, iret_exc)



#ifdef CONFIG_X86_ESPFIX32

ldt_ss:

.Lldt_ss:

/*

 * Setup and switch to ESPFIX stack

 *
@@ -562,7 +563,7 @@ ldt_ss: 
	 */

	DISABLE_INTERRUPTS(CLBR_EAX)

	lss	(%esp), %esp			/* switch to espfix segment */

	jmp	restore_nocheck

	jmp	.Lrestore_nocheck

#endif

ENDPROC(entry_INT80_32)
@@ -882,7 +883,7 @@ ftrace_call: 
	popl	%edx

	popl	%ecx

	popl	%eax

ftrace_ret:

.Lftrace_ret:

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

.globl ftrace_graph_call

ftrace_graph_call:
@@ -952,7 +953,7 @@ GLOBAL(ftrace_regs_call) 
	popl	%gs

	addl	$8, %esp			/* Skip orig_ax and ip */

	popf					/* Pop flags at end (no addl to corrupt flags) */

	jmp	ftrace_ret

	jmp	.Lftrace_ret



	popf

	jmp	ftrace_stub
@@ -963,7 +964,7 @@ ENTRY(mcount) 
	jb	ftrace_stub			/* Paging not enabled yet? */



	cmpl	$ftrace_stub, ftrace_trace_function

	jnz	trace

	jnz	.Ltrace

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

	cmpl	$ftrace_stub, ftrace_graph_return

	jnz	ftrace_graph_caller
@@ -976,7 +977,7 @@ ftrace_stub: 
	ret



	/* taken from glibc */

trace:

.Ltrace:

	pushl	%eax

	pushl	%ecx

	pushl	%edx
@@ -1116,7 +1117,7 @@ ENTRY(nmi) 
	movl	%ss, %eax

	cmpw	$__ESPFIX_SS, %ax

	popl	%eax

	je	nmi_espfix_stack

	je	.Lnmi_espfix_stack

#endif



	pushl	%eax				# pt_regs->orig_ax
@@ -1132,7 +1133,7 @@ ENTRY(nmi) 


	/* Not on SYSENTER stack. */

	call	do_nmi

	jmp	restore_all_notrace

	jmp	.Lrestore_all_notrace



.Lnmi_from_sysenter_stack:

	/*
@@ -1143,10 +1144,10 @@ ENTRY(nmi) 
	movl	PER_CPU_VAR(cpu_current_top_of_stack), %esp

	call	do_nmi

	movl	%ebp, %esp

	jmp	restore_all_notrace

	jmp	.Lrestore_all_notrace



#ifdef CONFIG_X86_ESPFIX32

nmi_espfix_stack:

.Lnmi_espfix_stack:

	/*

	 * create the pointer to lss back

	 */
@@ -1164,7 +1165,7 @@ nmi_espfix_stack: 
	call	do_nmi

	RESTORE_REGS

	lss	12+4(%esp), %esp		# back to espfix stack

	jmp	irq_return

	jmp	.Lirq_return

#endif

END(nmi)

arch/x86/kernel/head_32.S

+16 −16
Original line number Diff line number Diff line
@@ -248,19 +248,19 @@ page_pde_offset = (__PAGE_OFFSET >> 20); 
#ifdef CONFIG_PARAVIRT

	/* This is can only trip for a broken bootloader... */

	cmpw $0x207, pa(boot_params + BP_version)

	jb default_entry

	jb .Ldefault_entry



	/* Paravirt-compatible boot parameters.  Look to see what architecture

		we're booting under. */

	movl pa(boot_params + BP_hardware_subarch), %eax

	cmpl $num_subarch_entries, %eax

	jae bad_subarch

	jae .Lbad_subarch



	movl pa(subarch_entries)(,%eax,4), %eax

	subl $__PAGE_OFFSET, %eax

	jmp *%eax



bad_subarch:

.Lbad_subarch:

WEAK(lguest_entry)

WEAK(xen_entry)

	/* Unknown implementation; there's really
@@ -270,14 +270,14 @@ WEAK(xen_entry) 
	__INITDATA



subarch_entries:

	.long default_entry		/* normal x86/PC */

	.long .Ldefault_entry		/* normal x86/PC */

	.long lguest_entry		/* lguest hypervisor */

	.long xen_entry			/* Xen hypervisor */

	.long default_entry		/* Moorestown MID */

	.long .Ldefault_entry		/* Moorestown MID */

num_subarch_entries = (. - subarch_entries) / 4

.previous

#else

	jmp default_entry

	jmp .Ldefault_entry

#endif /* CONFIG_PARAVIRT */



#ifdef CONFIG_HOTPLUG_CPU
@@ -317,7 +317,7 @@ ENTRY(startup_32_smp) 
	call load_ucode_ap

#endif



default_entry:

.Ldefault_entry:

#define CR0_STATE	(X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | \

			 X86_CR0_NE | X86_CR0_WP | X86_CR0_AM | \

			 X86_CR0_PG)
@@ -347,7 +347,7 @@ default_entry: 
	pushfl

	popl %eax			# get EFLAGS

	testl $X86_EFLAGS_ID,%eax	# did EFLAGS.ID remained set?

	jz enable_paging		# hw disallowed setting of ID bit

	jz .Lenable_paging		# hw disallowed setting of ID bit

					# which means no CPUID and no CR4



	xorl %eax,%eax
@@ -357,13 +357,13 @@ default_entry: 
	movl $1,%eax

	cpuid

	andl $~1,%edx			# Ignore CPUID.FPU

	jz enable_paging		# No flags or only CPUID.FPU = no CR4

	jz .Lenable_paging		# No flags or only CPUID.FPU = no CR4



	movl pa(mmu_cr4_features),%eax

	movl %eax,%cr4



	testb $X86_CR4_PAE, %al		# check if PAE is enabled

	jz enable_paging

	jz .Lenable_paging



	/* Check if extended functions are implemented */

	movl $0x80000000, %eax
@@ -371,7 +371,7 @@ default_entry: 
	/* Value must be in the range 0x80000001 to 0x8000ffff */

	subl $0x80000001, %eax

	cmpl $(0x8000ffff-0x80000001), %eax

	ja enable_paging

	ja .Lenable_paging



	/* Clear bogus XD_DISABLE bits */

	call verify_cpu
@@ -380,7 +380,7 @@ default_entry: 
	cpuid

	/* Execute Disable bit supported? */

	btl $(X86_FEATURE_NX & 31), %edx

	jnc enable_paging

	jnc .Lenable_paging



	/* Setup EFER (Extended Feature Enable Register) */

	movl $MSR_EFER, %ecx
@@ -390,7 +390,7 @@ default_entry: 
	/* Make changes effective */

	wrmsr



enable_paging:

.Lenable_paging:



/*

 * Enable paging
@@ -419,7 +419,7 @@ enable_paging: 
 */

	movb $4,X86			# at least 486

	cmpl $-1,X86_CPUID

	je is486

	je .Lis486



	/* get vendor info */

	xorl %eax,%eax			# call CPUID with 0 -> return vendor ID
@@ -430,7 +430,7 @@ enable_paging: 
	movl %ecx,X86_VENDOR_ID+8	# last 4 chars



	orl %eax,%eax			# do we have processor info as well?

	je is486

	je .Lis486



	movl $1,%eax		# Use the CPUID instruction to get CPU type

	cpuid
@@ -444,7 +444,7 @@ enable_paging: 
	movb %cl,X86_MASK

	movl %edx,X86_CAPABILITY



is486:

.Lis486:

	movl $0x50022,%ecx	# set AM, WP, NE and MP

	movl %cr0,%eax

	andl $0x80000011,%eax	# Save PG,PE,ET

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