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authorLinus Torvalds <torvalds@linux-foundation.org>2016-12-12 13:49:57 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-12 13:49:57 -0800
commit5645688f9d0d5a32f030f9c5429e1a58bedca23b (patch)
tree0b576ba953fb26d521c6b8c3364848acb00ceef3 /arch/x86/kernel/head_32.S
parent4ade5b2268b9ff05e48a9cb99689c4fd15fbe9c3 (diff)
parent53938ee427bf27525a63721b7e25d86b8f31f161 (diff)
downloadlinux-5645688f9d0d5a32f030f9c5429e1a58bedca23b.tar.bz2
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Ingo Molnar: "The main changes in this development cycle were: - a large number of call stack dumping/printing improvements: higher robustness, better cross-context dumping, improved output, etc. (Josh Poimboeuf) - vDSO getcpu() performance improvement for future Intel CPUs with the RDPID instruction (Andy Lutomirski) - add two new Intel AVX512 features and the CPUID support infrastructure for it: AVX512IFMA and AVX512VBMI. (Gayatri Kammela, He Chen) - more copy-user unification (Borislav Petkov) - entry code assembly macro simplifications (Alexander Kuleshov) - vDSO C/R support improvements (Dmitry Safonov) - misc fixes and cleanups (Borislav Petkov, Paul Bolle)" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) scripts/decode_stacktrace.sh: Fix address line detection on x86 x86/boot/64: Use defines for page size x86/dumpstack: Make stack name tags more comprehensible selftests/x86: Add test_vdso to test getcpu() x86/vdso: Use RDPID in preference to LSL when available x86/dumpstack: Handle NULL stack pointer in show_trace_log_lvl() x86/cpufeatures: Enable new AVX512 cpu features x86/cpuid: Provide get_scattered_cpuid_leaf() x86/cpuid: Cleanup cpuid_regs definitions x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants x86/unwind: Ensure stack grows down x86/vdso: Set vDSO pointer only after success x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE x86/unwind: Detect bad stack return address x86/dumpstack: Warn on stack recursion x86/unwind: Warn on bad frame pointer x86/decoder: Use stderr if insn sanity test fails x86/decoder: Use stdout if insn decoder test is successful mm/page_alloc: Remove kernel address exposure in free_reserved_area() x86/dumpstack: Remove raw stack dump ...
Diffstat (limited to 'arch/x86/kernel/head_32.S')
-rw-r--r--arch/x86/kernel/head_32.S49
1 files changed, 29 insertions, 20 deletions
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 2dabea46f039..4e8577d03372 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -63,6 +63,8 @@
#define PAGE_TABLE_SIZE(pages) ((pages) / PTRS_PER_PGD)
#endif
+#define SIZEOF_PTREGS 17*4
+
/*
* Number of possible pages in the lowmem region.
*
@@ -248,19 +250,19 @@ 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 +272,14 @@ 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
@@ -289,7 +291,8 @@ num_subarch_entries = (. - subarch_entries) / 4
ENTRY(start_cpu0)
movl initial_stack, %ecx
movl %ecx, %esp
- jmp *(initial_code)
+ call *(initial_code)
+1: jmp 1b
ENDPROC(start_cpu0)
#endif
@@ -317,7 +320,7 @@ 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 +350,7 @@ 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 +360,13 @@ 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 +374,7 @@ 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 +383,7 @@ 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 +393,7 @@ default_entry:
/* Make changes effective */
wrmsr
-enable_paging:
+.Lenable_paging:
/*
* Enable paging
@@ -419,7 +422,7 @@ 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 +433,7 @@ 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 +447,7 @@ 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
@@ -470,8 +473,9 @@ is486:
xorl %eax,%eax # Clear LDT
lldt %ax
- pushl $0 # fake return address for unwinder
- jmp *(initial_code)
+ call *(initial_code)
+1: jmp 1b
+ENDPROC(startup_32_smp)
#include "verify_cpu.S"
@@ -709,7 +713,12 @@ ENTRY(initial_page_table)
.data
.balign 4
ENTRY(initial_stack)
- .long init_thread_union+THREAD_SIZE
+ /*
+ * The SIZEOF_PTREGS gap is a convention which helps the in-kernel
+ * unwinder reliably detect the end of the stack.
+ */
+ .long init_thread_union + THREAD_SIZE - SIZEOF_PTREGS - \
+ TOP_OF_KERNEL_STACK_PADDING;
__INITRODATA
int_msg: