From 1b00255f32b94b61897c83a22c05ed7d33229957 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 21 Sep 2016 16:03:59 -0500 Subject: [PATCH] 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: Josh Poimboeuf Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Nilay Vaish Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/14f9f7afd478b23a762f40734da1a57c0c273f6e.1474480779.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/entry/entry_32.S | 43 ++++++++++++++++++++------------------- arch/x86/kernel/head_32.S | 32 ++++++++++++++--------------- 2 files changed, 38 insertions(+), 37 deletions(-) diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 21b352a11b49..b03c1cb30145 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -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) diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index b6b2f0264af3..65e62256df43 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -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 -- 2.30.2