diff options
author | H. Peter Anvin <hpa@linux.intel.com> | 2011-02-04 19:14:11 -0500 |
---|---|---|
committer | H. Peter Anvin <hpa@zytor.com> | 2011-02-05 01:27:28 -0500 |
commit | 11d4c3f9b671720e80353dd7e433ff2bf65e9500 (patch) | |
tree | b3560b0642216e9c9e1a54e57a5f55845f063e6b /arch/x86 | |
parent | f7448548a9f32db38f243ccd4271617758ddfe2c (diff) |
x86-32: Make sure the stack is set up before we use it
Since checkin ebba638ae723d8a8fc2f7abce5ec18b688b791d7 we call
verify_cpu even in 32-bit mode. Unfortunately, calling a function
means using the stack, and the stack pointer was not initialized in
the 32-bit setup code! This code initializes the stack pointer, and
simplifies the interface slightly since it is easier to rely on just a
pointer value rather than a descriptor; we need to have different
values for the segment register anyway.
This retains start_stack as a virtual address, even though a physical
address would be more convenient for 32 bits; the 64-bit code wants
the other way around...
Reported-by: Matthieu Castet <castet.matthieu@free.fr>
LKML-Reference: <4D41E86D.8060205@free.fr>
Tested-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/include/asm/smp.h | 5 | ||||
-rw-r--r-- | arch/x86/kernel/acpi/sleep.c | 2 | ||||
-rw-r--r-- | arch/x86/kernel/head_32.S | 30 | ||||
-rw-r--r-- | arch/x86/kernel/smpboot.c | 4 |
4 files changed, 17 insertions, 24 deletions
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index 4c2f63c7fc1b..1f4695136776 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h | |||
@@ -40,10 +40,7 @@ DECLARE_EARLY_PER_CPU(u16, x86_cpu_to_apicid); | |||
40 | DECLARE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid); | 40 | DECLARE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid); |
41 | 41 | ||
42 | /* Static state in head.S used to set up a CPU */ | 42 | /* Static state in head.S used to set up a CPU */ |
43 | extern struct { | 43 | extern unsigned long stack_start; /* Initial stack pointer address */ |
44 | void *sp; | ||
45 | unsigned short ss; | ||
46 | } stack_start; | ||
47 | 44 | ||
48 | struct smp_ops { | 45 | struct smp_ops { |
49 | void (*smp_prepare_boot_cpu)(void); | 46 | void (*smp_prepare_boot_cpu)(void); |
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c index 69fd72aa5594..4d9ebbab2230 100644 --- a/arch/x86/kernel/acpi/sleep.c +++ b/arch/x86/kernel/acpi/sleep.c | |||
@@ -100,7 +100,7 @@ int acpi_save_state_mem(void) | |||
100 | #else /* CONFIG_64BIT */ | 100 | #else /* CONFIG_64BIT */ |
101 | header->trampoline_segment = setup_trampoline() >> 4; | 101 | header->trampoline_segment = setup_trampoline() >> 4; |
102 | #ifdef CONFIG_SMP | 102 | #ifdef CONFIG_SMP |
103 | stack_start.sp = temp_stack + sizeof(temp_stack); | 103 | stack_start = (unsigned long)temp_stack + sizeof(temp_stack); |
104 | early_gdt_descr.address = | 104 | early_gdt_descr.address = |
105 | (unsigned long)get_cpu_gdt_table(smp_processor_id()); | 105 | (unsigned long)get_cpu_gdt_table(smp_processor_id()); |
106 | initial_gs = per_cpu_offset(smp_processor_id()); | 106 | initial_gs = per_cpu_offset(smp_processor_id()); |
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index fc293dc8dc35..767d6c43de37 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S | |||
@@ -85,6 +85,8 @@ RESERVE_BRK(pagetables, INIT_MAP_SIZE) | |||
85 | */ | 85 | */ |
86 | __HEAD | 86 | __HEAD |
87 | ENTRY(startup_32) | 87 | ENTRY(startup_32) |
88 | movl pa(stack_start),%ecx | ||
89 | |||
88 | /* test KEEP_SEGMENTS flag to see if the bootloader is asking | 90 | /* test KEEP_SEGMENTS flag to see if the bootloader is asking |
89 | us to not reload segments */ | 91 | us to not reload segments */ |
90 | testb $(1<<6), BP_loadflags(%esi) | 92 | testb $(1<<6), BP_loadflags(%esi) |
@@ -99,7 +101,9 @@ ENTRY(startup_32) | |||
99 | movl %eax,%es | 101 | movl %eax,%es |
100 | movl %eax,%fs | 102 | movl %eax,%fs |
101 | movl %eax,%gs | 103 | movl %eax,%gs |
104 | movl %eax,%ss | ||
102 | 2: | 105 | 2: |
106 | leal -__PAGE_OFFSET(%ecx),%esp | ||
103 | 107 | ||
104 | /* | 108 | /* |
105 | * Clear BSS first so that there are no surprises... | 109 | * Clear BSS first so that there are no surprises... |
@@ -145,8 +149,6 @@ ENTRY(startup_32) | |||
145 | * _brk_end is set up to point to the first "safe" location. | 149 | * _brk_end is set up to point to the first "safe" location. |
146 | * Mappings are created both at virtual address 0 (identity mapping) | 150 | * Mappings are created both at virtual address 0 (identity mapping) |
147 | * and PAGE_OFFSET for up to _end. | 151 | * and PAGE_OFFSET for up to _end. |
148 | * | ||
149 | * Note that the stack is not yet set up! | ||
150 | */ | 152 | */ |
151 | #ifdef CONFIG_X86_PAE | 153 | #ifdef CONFIG_X86_PAE |
152 | 154 | ||
@@ -282,6 +284,9 @@ ENTRY(startup_32_smp) | |||
282 | movl %eax,%es | 284 | movl %eax,%es |
283 | movl %eax,%fs | 285 | movl %eax,%fs |
284 | movl %eax,%gs | 286 | movl %eax,%gs |
287 | movl pa(stack_start),%ecx | ||
288 | movl %eax,%ss | ||
289 | leal -__PAGE_OFFSET(%ecx),%esp | ||
285 | #endif /* CONFIG_SMP */ | 290 | #endif /* CONFIG_SMP */ |
286 | default_entry: | 291 | default_entry: |
287 | 292 | ||
@@ -347,8 +352,8 @@ default_entry: | |||
347 | movl %eax,%cr0 /* ..and set paging (PG) bit */ | 352 | movl %eax,%cr0 /* ..and set paging (PG) bit */ |
348 | ljmp $__BOOT_CS,$1f /* Clear prefetch and normalize %eip */ | 353 | ljmp $__BOOT_CS,$1f /* Clear prefetch and normalize %eip */ |
349 | 1: | 354 | 1: |
350 | /* Set up the stack pointer */ | 355 | /* Shift the stack pointer to a virtual address */ |
351 | lss stack_start,%esp | 356 | addl $__PAGE_OFFSET, %esp |
352 | 357 | ||
353 | /* | 358 | /* |
354 | * Initialize eflags. Some BIOS's leave bits like NT set. This would | 359 | * Initialize eflags. Some BIOS's leave bits like NT set. This would |
@@ -360,9 +365,7 @@ default_entry: | |||
360 | 365 | ||
361 | #ifdef CONFIG_SMP | 366 | #ifdef CONFIG_SMP |
362 | cmpb $0, ready | 367 | cmpb $0, ready |
363 | jz 1f /* Initial CPU cleans BSS */ | 368 | jnz checkCPUtype |
364 | jmp checkCPUtype | ||
365 | 1: | ||
366 | #endif /* CONFIG_SMP */ | 369 | #endif /* CONFIG_SMP */ |
367 | 370 | ||
368 | /* | 371 | /* |
@@ -470,14 +473,7 @@ is386: movl $2,%ecx # set MP | |||
470 | 473 | ||
471 | cld # gcc2 wants the direction flag cleared at all times | 474 | cld # gcc2 wants the direction flag cleared at all times |
472 | pushl $0 # fake return address for unwinder | 475 | pushl $0 # fake return address for unwinder |
473 | #ifdef CONFIG_SMP | ||
474 | movb ready, %cl | ||
475 | movb $1, ready | 476 | movb $1, ready |
476 | cmpb $0,%cl # the first CPU calls start_kernel | ||
477 | je 1f | ||
478 | movl (stack_start), %esp | ||
479 | 1: | ||
480 | #endif /* CONFIG_SMP */ | ||
481 | jmp *(initial_code) | 477 | jmp *(initial_code) |
482 | 478 | ||
483 | /* | 479 | /* |
@@ -670,15 +666,15 @@ ENTRY(initial_page_table) | |||
670 | #endif | 666 | #endif |
671 | 667 | ||
672 | .data | 668 | .data |
669 | .balign 4 | ||
673 | ENTRY(stack_start) | 670 | ENTRY(stack_start) |
674 | .long init_thread_union+THREAD_SIZE | 671 | .long init_thread_union+THREAD_SIZE |
675 | .long __BOOT_DS | ||
676 | |||
677 | ready: .byte 0 | ||
678 | 672 | ||
679 | early_recursion_flag: | 673 | early_recursion_flag: |
680 | .long 0 | 674 | .long 0 |
681 | 675 | ||
676 | ready: .byte 0 | ||
677 | |||
682 | int_msg: | 678 | int_msg: |
683 | .asciz "Unknown interrupt or fault at: %p %p %p\n" | 679 | .asciz "Unknown interrupt or fault at: %p %p %p\n" |
684 | 680 | ||
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 0cbe8c0b35ed..03273b6c272c 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c | |||
@@ -638,7 +638,7 @@ wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip) | |||
638 | * target processor state. | 638 | * target processor state. |
639 | */ | 639 | */ |
640 | startup_ipi_hook(phys_apicid, (unsigned long) start_secondary, | 640 | startup_ipi_hook(phys_apicid, (unsigned long) start_secondary, |
641 | (unsigned long)stack_start.sp); | 641 | stack_start); |
642 | 642 | ||
643 | /* | 643 | /* |
644 | * Run STARTUP IPI loop. | 644 | * Run STARTUP IPI loop. |
@@ -785,7 +785,7 @@ do_rest: | |||
785 | #endif | 785 | #endif |
786 | early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu); | 786 | early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu); |
787 | initial_code = (unsigned long)start_secondary; | 787 | initial_code = (unsigned long)start_secondary; |
788 | stack_start.sp = (void *) c_idle.idle->thread.sp; | 788 | stack_start = c_idle.idle->thread.sp; |
789 | 789 | ||
790 | /* start_ip had better be page-aligned! */ | 790 | /* start_ip had better be page-aligned! */ |
791 | start_ip = setup_trampoline(); | 791 | start_ip = setup_trampoline(); |