diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-23 10:44:35 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-23 10:44:35 -0700 |
commit | 269af9a1a08d368b46d72e74126564d04c354f7e (patch) | |
tree | f0f2a8dd54075edebbb728602822e2b7378588d0 /arch | |
parent | 8ca038dc10eec80f280d9d483f1835ac2763a787 (diff) | |
parent | 8b5ad472991796b2347464922c72de2ca5a028f3 (diff) |
Merge branch 'x86-extable-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull exception table generation updates from Ingo Molnar:
"The biggest change here is to allow the build-time sorting of the
exception table, to speed up booting. This is achieved by the
architecture enabling BUILDTIME_EXTABLE_SORT. This option is enabled
for x86 and MIPS currently.
On x86 a number of fixes and changes were needed to allow build-time
sorting of the exception table, in particular a relocation invariant
exception table format was needed. This required the abstracting out
of exception table protocol and the removal of 20 years of accumulated
assumptions about the x86 exception table format.
While at it, this tree also cleans up various other aspects of
exception handling, such as early(er) exception handling for
rdmsr_safe() et al.
All in one, as the result of these changes the x86 exception code is
now pretty nice and modern. As an added bonus any regressions in this
code will be early and violent crashes, so if you see any of those,
you'll know whom to blame!"
Fix up trivial conflicts in arch/{mips,x86}/Kconfig files due to nearby
modifications of other core architecture options.
* 'x86-extable-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits)
Revert "x86, extable: Disable presorted exception table for now"
scripts/sortextable: Handle relative entries, and other cleanups
x86, extable: Switch to relative exception table entries
x86, extable: Disable presorted exception table for now
x86, extable: Add _ASM_EXTABLE_EX() macro
x86, extable: Remove open-coded exception table entries in arch/x86/ia32/ia32entry.S
x86, extable: Remove open-coded exception table entries in arch/x86/include/asm/xsave.h
x86, extable: Remove open-coded exception table entries in arch/x86/include/asm/kvm_host.h
x86, extable: Remove the now-unused __ASM_EX_SEC macros
x86, extable: Remove open-coded exception table entries in arch/x86/xen/xen-asm_32.S
x86, extable: Remove open-coded exception table entries in arch/x86/um/checksum_32.S
x86, extable: Remove open-coded exception table entries in arch/x86/lib/usercopy_32.c
x86, extable: Remove open-coded exception table entries in arch/x86/lib/putuser.S
x86, extable: Remove open-coded exception table entries in arch/x86/lib/getuser.S
x86, extable: Remove open-coded exception table entries in arch/x86/lib/csum-copy_64.S
x86, extable: Remove open-coded exception table entries in arch/x86/lib/copy_user_nocache_64.S
x86, extable: Remove open-coded exception table entries in arch/x86/lib/copy_user_64.S
x86, extable: Remove open-coded exception table entries in arch/x86/lib/checksum_32.S
x86, extable: Remove open-coded exception table entries in arch/x86/kernel/test_rodata.c
x86, extable: Remove open-coded exception table entries in arch/x86/kernel/entry_64.S
...
Diffstat (limited to 'arch')
26 files changed, 581 insertions, 455 deletions
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index f5e121213c22..85aad0321397 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -30,6 +30,7 @@ config MIPS select HAVE_MEMBLOCK_NODE_MAP select ARCH_DISCARD_MEMBLOCK select GENERIC_SMP_IDLE_THREAD + select BUILDTIME_EXTABLE_SORT menu "Machine selection" diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 7b383d8da7b9..21ea6d28d71f 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -83,6 +83,7 @@ config X86 select DCACHE_WORD_ACCESS select GENERIC_SMP_IDLE_THREAD select HAVE_ARCH_SECCOMP_FILTER + select BUILDTIME_EXTABLE_SORT config INSTRUCTION_DECODER def_bool (KPROBES || PERF_EVENTS) diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index e3e734005e19..20e5f7ba0e6b 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -13,6 +13,7 @@ #include <asm/thread_info.h> #include <asm/segment.h> #include <asm/irqflags.h> +#include <asm/asm.h> #include <linux/linkage.h> #include <linux/err.h> @@ -146,9 +147,7 @@ ENTRY(ia32_sysenter_target) /* no need to do an access_ok check here because rbp has been 32bit zero extended */ 1: movl (%rbp),%ebp - .section __ex_table,"a" - .quad 1b,ia32_badarg - .previous + _ASM_EXTABLE(1b,ia32_badarg) orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP-ARGOFFSET) testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) CFI_REMEMBER_STATE @@ -303,9 +302,7 @@ ENTRY(ia32_cstar_target) 32bit zero extended */ /* hardware stack frame is complete now */ 1: movl (%r8),%r9d - .section __ex_table,"a" - .quad 1b,ia32_badarg - .previous + _ASM_EXTABLE(1b,ia32_badarg) orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP-ARGOFFSET) testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) CFI_REMEMBER_STATE diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h index 9412d6558c88..1c2d247f65ce 100644 --- a/arch/x86/include/asm/asm.h +++ b/arch/x86/include/asm/asm.h @@ -4,11 +4,9 @@ #ifdef __ASSEMBLY__ # define __ASM_FORM(x) x # define __ASM_FORM_COMMA(x) x, -# define __ASM_EX_SEC .section __ex_table, "a" #else # define __ASM_FORM(x) " " #x " " # define __ASM_FORM_COMMA(x) " " #x "," -# define __ASM_EX_SEC " .section __ex_table,\"a\"\n" #endif #ifdef CONFIG_X86_32 @@ -42,17 +40,33 @@ /* Exception table entry */ #ifdef __ASSEMBLY__ -# define _ASM_EXTABLE(from,to) \ - __ASM_EX_SEC ; \ - _ASM_ALIGN ; \ - _ASM_PTR from , to ; \ - .previous +# define _ASM_EXTABLE(from,to) \ + .pushsection "__ex_table","a" ; \ + .balign 8 ; \ + .long (from) - . ; \ + .long (to) - . ; \ + .popsection + +# define _ASM_EXTABLE_EX(from,to) \ + .pushsection "__ex_table","a" ; \ + .balign 8 ; \ + .long (from) - . ; \ + .long (to) - . + 0x7ffffff0 ; \ + .popsection #else -# define _ASM_EXTABLE(from,to) \ - __ASM_EX_SEC \ - _ASM_ALIGN "\n" \ - _ASM_PTR #from "," #to "\n" \ - " .previous\n" +# define _ASM_EXTABLE(from,to) \ + " .pushsection \"__ex_table\",\"a\"\n" \ + " .balign 8\n" \ + " .long (" #from ") - .\n" \ + " .long (" #to ") - .\n" \ + " .popsection\n" + +# define _ASM_EXTABLE_EX(from,to) \ + " .pushsection \"__ex_table\",\"a\"\n" \ + " .balign 8\n" \ + " .long (" #from ") - .\n" \ + " .long (" #to ") - . + 0x7ffffff0\n" \ + " .popsection\n" #endif #endif /* _ASM_X86_ASM_H */ diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index e216ba066e79..e5b97be12d2a 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -27,6 +27,7 @@ #include <asm/desc.h> #include <asm/mtrr.h> #include <asm/msr-index.h> +#include <asm/asm.h> #define KVM_MAX_VCPUS 254 #define KVM_SOFT_MAX_VCPUS 160 @@ -921,9 +922,7 @@ extern bool kvm_rebooting; __ASM_SIZE(push) " $666b \n\t" \ "call kvm_spurious_fault \n\t" \ ".popsection \n\t" \ - ".pushsection __ex_table, \"a\" \n\t" \ - _ASM_PTR " 666b, 667b \n\t" \ - ".popsection" + _ASM_EXTABLE(666b, 667b) #define __kvm_handle_fault_on_reboot(insn) \ ____kvm_handle_fault_on_reboot(insn, "") diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h index 95203d40ffdd..084ef95274cd 100644 --- a/arch/x86/include/asm/msr.h +++ b/arch/x86/include/asm/msr.h @@ -169,14 +169,7 @@ static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high) return native_write_msr_safe(msr, low, high); } -/* - * rdmsr with exception handling. - * - * Please note that the exception handling works only after we've - * switched to the "smart" #GP handler in trap_init() which knows about - * exception tables - using this macro earlier than that causes machine - * hangs on boxes which do not implement the @msr in the first argument. - */ +/* rdmsr with exception handling */ #define rdmsr_safe(msr, p1, p2) \ ({ \ int __err; \ diff --git a/arch/x86/include/asm/nops.h b/arch/x86/include/asm/nops.h index 405b4032a60b..aff2b3356101 100644 --- a/arch/x86/include/asm/nops.h +++ b/arch/x86/include/asm/nops.h @@ -87,7 +87,11 @@ #define P6_NOP8 0x0f,0x1f,0x84,0x00,0,0,0,0 #define P6_NOP5_ATOMIC P6_NOP5 +#ifdef __ASSEMBLY__ +#define _ASM_MK_NOP(x) .byte x +#else #define _ASM_MK_NOP(x) ".byte " __stringify(x) "\n" +#endif #if defined(CONFIG_MK7) #define ASM_NOP1 _ASM_MK_NOP(K7_NOP1) diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index aa0f91308367..6cbbabf52707 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -1023,10 +1023,8 @@ extern void default_banner(void); call PARA_INDIRECT(pv_cpu_ops+PV_CPU_swapgs) \ ) -#define GET_CR2_INTO_RCX \ - call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2); \ - movq %rax, %rcx; \ - xorq %rax, %rax; +#define GET_CR2_INTO_RAX \ + call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2) #define PARAVIRT_ADJUST_EXCEPTION_FRAME \ PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_adjust_exception_frame), \ diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h index 165466233ab0..c48a95035a77 100644 --- a/arch/x86/include/asm/segment.h +++ b/arch/x86/include/asm/segment.h @@ -205,13 +205,15 @@ #define IDT_ENTRIES 256 #define NUM_EXCEPTION_VECTORS 32 +/* Bitmask of exception vectors which push an error code on the stack */ +#define EXCEPTION_ERRCODE_MASK 0x00027d00 #define GDT_SIZE (GDT_ENTRIES * 8) #define GDT_ENTRY_TLS_ENTRIES 3 #define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8) #ifdef __KERNEL__ #ifndef __ASSEMBLY__ -extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][10]; +extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][2+2+5]; /* * Load a segment. Fall back on loading the zero diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index e0544597cfe7..851fe0dc13bc 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -79,11 +79,12 @@ #define access_ok(type, addr, size) (likely(__range_not_ok(addr, size) == 0)) /* - * The exception table consists of pairs of addresses: the first is the - * address of an instruction that is allowed to fault, and the second is - * the address at which the program should continue. No registers are - * modified, so it is entirely up to the continuation code to figure out - * what to do. + * The exception table consists of pairs of addresses relative to the + * exception table enty itself: the first is the address of an + * instruction that is allowed to fault, and the second is the address + * at which the program should continue. No registers are modified, + * so it is entirely up to the continuation code to figure out what to + * do. * * All the routines below use bits of fixup code that are out of line * with the main instruction path. This means when everything is well, @@ -92,10 +93,14 @@ */ struct exception_table_entry { - unsigned long insn, fixup; + int insn, fixup; }; +/* This is not the generic standard exception_table_entry format */ +#define ARCH_HAS_SORT_EXTABLE +#define ARCH_HAS_SEARCH_EXTABLE extern int fixup_exception(struct pt_regs *regs); +extern int early_fixup_exception(unsigned long *ip); /* * These are the main single-value transfer routines. They automatically @@ -202,8 +207,8 @@ extern int __get_user_bad(void); asm volatile("1: movl %%eax,0(%1)\n" \ "2: movl %%edx,4(%1)\n" \ "3:\n" \ - _ASM_EXTABLE(1b, 2b - 1b) \ - _ASM_EXTABLE(2b, 3b - 2b) \ + _ASM_EXTABLE_EX(1b, 2b) \ + _ASM_EXTABLE_EX(2b, 3b) \ : : "A" (x), "r" (addr)) #define __put_user_x8(x, ptr, __ret_pu) \ @@ -408,7 +413,7 @@ do { \ #define __get_user_asm_ex(x, addr, itype, rtype, ltype) \ asm volatile("1: mov"itype" %1,%"rtype"0\n" \ "2:\n" \ - _ASM_EXTABLE(1b, 2b - 1b) \ + _ASM_EXTABLE_EX(1b, 2b) \ : ltype(x) : "m" (__m(addr))) #define __put_user_nocheck(x, ptr, size) \ @@ -450,7 +455,7 @@ struct __large_struct { unsigned long buf[100]; }; #define __put_user_asm_ex(x, addr, itype, rtype, ltype) \ asm volatile("1: mov"itype" %"rtype"0,%1\n" \ "2:\n" \ - _ASM_EXTABLE(1b, 2b - 1b) \ + _ASM_EXTABLE_EX(1b, 2b) \ : : ltype(x), "m" (__m(addr))) /* diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h index c6ce2452f10c..8a1b6f9b594a 100644 --- a/arch/x86/include/asm/xsave.h +++ b/arch/x86/include/asm/xsave.h @@ -80,10 +80,7 @@ static inline int xsave_user(struct xsave_struct __user *buf) "3: movl $-1,%[err]\n" " jmp 2b\n" ".previous\n" - ".section __ex_table,\"a\"\n" - _ASM_ALIGN "\n" - _ASM_PTR "1b,3b\n" - ".previous" + _ASM_EXTABLE(1b,3b) : [err] "=r" (err) : "D" (buf), "a" (-1), "d" (-1), "0" (0) : "memory"); @@ -106,10 +103,7 @@ static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask) "3: movl $-1,%[err]\n" " jmp 2b\n" ".previous\n" - ".section __ex_table,\"a\"\n" - _ASM_ALIGN "\n" - _ASM_PTR "1b,3b\n" - ".previous" + _ASM_EXTABLE(1b,3b) : [err] "=r" (err) : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0) : "memory"); /* memory required? */ diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 7b784f4ef1e4..01ccf9b71473 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -56,6 +56,7 @@ #include <asm/irq_vectors.h> #include <asm/cpufeature.h> #include <asm/alternative-asm.h> +#include <asm/asm.h> /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */ #include <linux/elf-em.h> @@ -151,10 +152,8 @@ .pushsection .fixup, "ax" 99: movl $0, (%esp) jmp 98b -.section __ex_table, "a" - .align 4 - .long 98b, 99b .popsection + _ASM_EXTABLE(98b,99b) .endm .macro PTGS_TO_GS @@ -164,10 +163,8 @@ .pushsection .fixup, "ax" 99: movl $0, PT_GS(%esp) jmp 98b -.section __ex_table, "a" - .align 4 - .long 98b, 99b .popsection + _ASM_EXTABLE(98b,99b) .endm .macro GS_TO_REG reg @@ -249,12 +246,10 @@ jmp 2b 6: movl $0, (%esp) jmp 3b -.section __ex_table, "a" - .align 4 - .long 1b, 4b - .long 2b, 5b - .long 3b, 6b .popsection + _ASM_EXTABLE(1b,4b) + _ASM_EXTABLE(2b,5b) + _ASM_EXTABLE(3b,6b) POP_GS_EX .endm @@ -415,10 +410,7 @@ sysenter_past_esp: jae syscall_fault 1: movl (%ebp),%ebp movl %ebp,PT_EBP(%esp) -.section __ex_table,"a" - .align 4 - .long 1b,syscall_fault -.previous + _ASM_EXTABLE(1b,syscall_fault) GET_THREAD_INFO(%ebp) @@ -485,10 +477,8 @@ sysexit_audit: .pushsection .fixup,"ax" 2: movl $0,PT_FS(%esp) jmp 1b -.section __ex_table,"a" - .align 4 - .long 1b,2b .popsection + _ASM_EXTABLE(1b,2b) PTGS_TO_GS_EX ENDPROC(ia32_sysenter_target) @@ -543,10 +533,7 @@ ENTRY(iret_exc) pushl $do_iret_error jmp error_code .previous -.section __ex_table,"a" - .align 4 - .long irq_return,iret_exc -.previous + _ASM_EXTABLE(irq_return,iret_exc) CFI_RESTORE_STATE ldt_ss: @@ -901,10 +888,7 @@ END(device_not_available) #ifdef CONFIG_PARAVIRT ENTRY(native_iret) iret -.section __ex_table,"a" - .align 4 - .long native_iret, iret_exc -.previous + _ASM_EXTABLE(native_iret, iret_exc) END(native_iret) ENTRY(native_irq_enable_sysexit) @@ -1093,13 +1077,10 @@ ENTRY(xen_failsafe_callback) movl %eax,16(%esp) jmp 4b .previous -.section __ex_table,"a" - .align 4 - .long 1b,6b - .long 2b,7b - .long 3b,8b - .long 4b,9b -.previous + _ASM_EXTABLE(1b,6b) + _ASM_EXTABLE(2b,7b) + _ASM_EXTABLE(3b,8b) + _ASM_EXTABLE(4b,9b) ENDPROC(xen_failsafe_callback) BUILD_INTERRUPT3(xen_hvm_callback_vector, XEN_HVM_EVTCHN_CALLBACK, diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index cdc79b5cfcd9..320852d02026 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -55,6 +55,7 @@ #include <asm/paravirt.h> #include <asm/ftrace.h> #include <asm/percpu.h> +#include <asm/asm.h> #include <linux/err.h> /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */ @@ -900,18 +901,12 @@ restore_args: irq_return: INTERRUPT_RETURN - - .section __ex_table, "a" - .quad irq_return, bad_iret - .previous + _ASM_EXTABLE(irq_return, bad_iret) #ifdef CONFIG_PARAVIRT ENTRY(native_iret) iretq - - .section __ex_table,"a" - .quad native_iret, bad_iret - .previous + _ASM_EXTABLE(native_iret, bad_iret) #endif .section .fixup,"ax" @@ -1181,10 +1176,7 @@ gs_change: CFI_ENDPROC END(native_load_gs_index) - .section __ex_table,"a" - .align 8 - .quad gs_change,bad_gs - .previous + _ASM_EXTABLE(gs_change,bad_gs) .section .fixup,"ax" /* running with kernelgs */ bad_gs: diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index ce0be7cd085e..463c9797ca6a 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -21,6 +21,7 @@ #include <asm/msr-index.h> #include <asm/cpufeature.h> #include <asm/percpu.h> +#include <asm/nops.h> /* Physical address */ #define pa(X) ((X) - __PAGE_OFFSET) @@ -363,28 +364,23 @@ default_entry: pushl $0 popfl -#ifdef CONFIG_SMP - cmpb $0, ready - jnz checkCPUtype -#endif /* CONFIG_SMP */ - /* * start system 32-bit setup. We need to re-do some of the things done * in 16-bit mode for the "real" operations. */ - call setup_idt - -checkCPUtype: - - movl $-1,X86_CPUID # -1 for no CPUID initially - + movl setup_once_ref,%eax + andl %eax,%eax + jz 1f # Did we do this already? + call *%eax +1: + /* check if it is 486 or 386. */ /* * XXX - this does a lot of unnecessary setup. Alignment checks don't * apply at our cpl of 0 and the stack ought to be aligned already, and * we don't need to preserve eflags. */ - + movl $-1,X86_CPUID # -1 for no CPUID initially movb $3,X86 # at least 386 pushfl # push EFLAGS popl %eax # get EFLAGS @@ -450,21 +446,6 @@ is386: movl $2,%ecx # set MP movl $(__KERNEL_PERCPU), %eax movl %eax,%fs # set this cpu's percpu -#ifdef CONFIG_CC_STACKPROTECTOR - /* - * The linker can't handle this by relocation. Manually set - * base address in stack canary segment descriptor. - */ - cmpb $0,ready - jne 1f - movl $gdt_page,%eax - movl $stack_canary,%ecx - movw %cx, 8 * GDT_ENTRY_STACK_CANARY + 2(%eax) - shrl $16, %ecx - movb %cl, 8 * GDT_ENTRY_STACK_CANARY + 4(%eax) - movb %ch, 8 * GDT_ENTRY_STACK_CANARY + 7(%eax) -1: -#endif movl $(__KERNEL_STACK_CANARY),%eax movl %eax,%gs @@ -473,7 +454,6 @@ is386: movl $2,%ecx # set MP cld # gcc2 wants the direction flag cleared at all times pushl $0 # fake return address for unwinder - movb $1, ready jmp *(initial_code) /* @@ -495,81 +475,122 @@ check_x87: .byte 0xDB,0xE4 /* fsetpm for 287, ignored by 387 */ ret + +#include "verify_cpu.S" + /* - * setup_idt + * setup_once * - * sets up a idt with 256 entries pointing to - * ignore_int, interrupt gates. It doesn't actually load - * idt - that can be done only after paging has been enabled - * and the kernel moved to PAGE_OFFSET. Interrupts - * are enabled elsewhere, when we can be relatively - * sure everything is ok. + * The setup work we only want to run on the BSP. * * Warning: %esi is live across this function. */ -setup_idt: - lea ignore_int,%edx - movl $(__KERNEL_CS << 16),%eax - movw %dx,%ax /* selector = 0x0010 = cs */ - movw $0x8E00,%dx /* interrupt gate - dpl=0, present */ +__INIT +setup_once: + /* + * Set up a idt with 256 entries pointing to ignore_int, + * interrupt gates. It doesn't actually load idt - that needs + * to be done on each CPU. Interrupts are enabled elsewhere, + * when we can be relatively sure everything is ok. + */ - lea idt_table,%edi - mov $256,%ecx -rp_sidt: + movl $idt_table,%edi + movl $early_idt_handlers,%eax + movl $NUM_EXCEPTION_VECTORS,%ecx +1: movl %eax,(%edi) - movl %edx,4(%edi) + movl %eax,4(%edi) + /* interrupt gate, dpl=0, present */ + movl $(0x8E000000 + __KERNEL_CS),2(%edi) + addl $9,%eax addl $8,%edi - dec %ecx - jne rp_sidt + loop 1b -.macro set_early_handler handler,trapno - lea \handler,%edx + movl $256 - NUM_EXCEPTION_VECTORS,%ecx + movl $ignore_int,%edx movl $(__KERNEL_CS << 16),%eax - movw %dx,%ax + movw %dx,%ax /* selector = 0x0010 = cs */ movw $0x8E00,%dx /* interrupt gate - dpl=0, present */ - lea idt_table,%edi - movl %eax,8*\trapno(%edi) - movl %edx,8*\trapno+4(%edi) -.endm +2: + movl %eax,(%edi) + movl %edx,4(%edi) + addl $8,%edi + loop 2b - set_early_handler handler=early_divide_err,trapno=0 - set_early_handler handler=early_illegal_opcode,trapno=6 - set_early_handler handler=early_protection_fault,trapno=13 - set_early_handler handler=early_page_fault,trapno=14 +#ifdef CONFIG_CC_STACKPROTECTOR + /* + * Configure the stack canary. The linker can't handle this by + * relocation. Manually set base address in stack canary + * segment descriptor. + */ + movl $gdt_page,%eax + movl $stack_canary,%ecx + movw %cx, 8 * GDT_ENTRY_STACK_CANARY + 2(%eax) + shrl $16, %ecx + movb %cl, 8 * GDT_ENTRY_STACK_CANARY + 4(%eax) + movb %ch, 8 * GDT_ENTRY_STACK_CANARY + 7(%eax) +#endif + andl $0,setup_once_ref /* Once is enough, thanks */ ret -early_divide_err: - xor %edx,%edx - pushl $0 /* fake errcode */ - jmp early_fault +ENTRY(early_idt_handlers) + # 36(%esp) %eflags + # 32(%esp) %cs + # 28(%esp) %eip + # 24(%rsp) error code + i = 0 + .rept NUM_EXCEPTION_VECTORS + .if (EXCEPTION_ERRCODE_MASK >> i) & 1 + ASM_NOP2 + .else + pushl $0 # Dummy error code, to make stack frame uniform + .endif + pushl $i # 20(%esp) Vector number + jmp early_idt_handler + i = i + 1 + .endr +ENDPROC(early_idt_handlers) + + /* This is global to keep gas from relaxing the jumps */ +ENTRY(early_idt_handler) + cld + cmpl $2,%ss:early_recursion_flag + je hlt_loop + incl %ss:early_recursion_flag -early_illegal_opcode: - movl $6,%edx - pushl $0 /* fake errcode */ - jmp early_fault + push %eax # 16(%esp) + push %ecx # 12(%esp) + push %edx # 8(%esp) + push %ds # 4(%esp) + push %es # 0(%esp) + movl $(__KERNEL_DS),%eax + movl %eax,%ds + movl %eax,%es -early_protection_fault: - movl $13,%edx - jmp early_fault + cmpl $(__KERNEL_CS),32(%esp) + jne 10f -early_page_fault: - movl $14,%edx - jmp early_fault + leal 28(%esp),%eax # Pointer to %eip + call early_fixup_exception + andl %eax,%eax + jnz ex_entry /* found an exception entry */ -early_fault: - cld +10: #ifdef CONFIG_PRINTK - pusha - movl $(__KERNEL_DS),%eax - movl %eax,%ds - movl %eax,%es - cmpl $2,early_recursion_flag - je hlt_loop - incl early_recursion_flag + xorl %eax,%eax + movw %ax,2(%esp) /* clean up the segment values on some cpus */ + movw %ax,6(%esp) + movw %ax,34(%esp) + leal 40(%esp),%eax + pushl %eax /* %esp before the exception */ + pushl %ebx + pushl %ebp + pushl %esi + pushl %edi movl %cr2,%eax pushl %eax - pushl %edx /* trapno */ + pushl (20+6*4)(%esp) /* trapno */ pushl $fault_msg call printk #endif @@ -578,6 +599,17 @@ hlt_loop: hlt jmp hlt_loop +ex_entry: + pop %es + pop %ds + pop %edx + pop %ecx + pop %eax + addl $8,%esp /* drop vector number and error code */ + decl %ss:early_recursion_flag + iret +ENDPROC(early_idt_handler) + /* This is the default interrupt "handler" :-) */ ALIGN ignore_int: @@ -611,13 +643,18 @@ ignore_int: popl %eax #endif iret +ENDPROC(ignore_int) +__INITDATA + .align 4 +early_recursion_flag: + .long 0 -#include "verify_cpu.S" - - __REFDATA -.align 4 +__REFDATA + .align 4 ENTRY(initial_code) .long i386_start_kernel +ENTRY(setup_once_ref) + .long setup_once /* * BSS section @@ -670,22 +707,19 @@ ENTRY(initial_page_table) ENTRY(stack_start) .long init_thread_union+THREAD_SIZE -early_recursion_flag: - .long 0 - -ready: .byte 0 - +__INITRODATA int_msg: .asciz "Unknown interrupt or fault at: %p %p %p\n" fault_msg: /* fault info: */ .ascii "BUG: Int %d: CR2 %p\n" -/* pusha regs: */ - .ascii " EDI %p ESI %p EBP %p ESP %p\n" - .ascii " EBX %p EDX %p ECX %p EAX %p\n" +/* regs pushed in early_idt_handler: */ + .ascii " EDI %p ESI %p EBP %p EBX %p\n" + .ascii " ESP %p ES %p DS %p\n" + .ascii " EDX %p ECX %p EAX %p\n" /* fault frame: */ - .ascii " err %p EIP %p CS %p flg %p\n" + .ascii " vec %p err %p EIP %p CS %p flg %p\n" .ascii "Stack: %p %p %p %p %p %p %p %p\n" .ascii " %p %p %p %p %p %p %p %p\n" .asciz " %p %p %p %p %p %p %p %p\n" @@ -699,6 +733,7 @@ fault_msg: * segment size, and 32-bit linear address value: */ + .data .globl boot_gdt_descr .globl idt_descr diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 40f4eb3766d1..7a40f2447321 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -19,12 +19,15 @@ #include <asm/cache.h> #include <asm/processor-flags.h> #include <asm/percpu.h> +#include <asm/nops.h> #ifdef CONFIG_PARAVIRT #include <asm/asm-offsets.h> #include <asm/paravirt.h> +#define GET_CR2_INTO(reg) GET_CR2_INTO_RAX ; movq %rax, reg #else -#define GET_CR2_INTO_RCX movq %cr2, %rcx +#define GET_CR2_INTO(reg) movq %cr2, reg +#define INTERRUPT_RETURN iretq #endif /* we are not able to switch in one step to the final KERNEL ADDRESS SPACE @@ -270,36 +273,56 @@ bad_address: jmp bad_address .section ".init.text","ax" -#ifdef CONFIG_EARLY_PRINTK .globl early_idt_handlers early_idt_handlers: + # 104(%rsp) %rflags + # 96(%rsp) %cs + # 88(%rsp) %rip + # 80(%rsp) error code i = 0 .rept NUM_EXCEPTION_VECTORS - movl $i, %esi + .if (EXCEPTION_ERRCODE_MASK >> i) & 1 + ASM_NOP2 + .else + pushq $0 # Dummy error code, to make stack frame uniform + .endif + pushq $i # 72(%rsp) Vector number jmp early_idt_handler i = i + 1 .endr -#endif ENTRY(early_idt_handler) -#ifdef CONFIG_EARLY_PRINTK + cld + cmpl $2,early_recursion_flag(%rip) jz 1f incl early_recursion_flag(%rip) - GET_CR2_INTO_RCX - movq %rcx,%r9 - xorl %r8d,%r8d # zero for error code - movl %esi,%ecx # get vector number - # Test %ecx against mask of vectors that push error code. - cmpl $31,%ecx - ja 0f - movl $1,%eax - salq %cl,%rax - testl $0x27d00,%eax - je 0f - popq %r8 # get error code -0: movq 0(%rsp),%rcx # get ip - movq 8(%rsp),%rdx # get cs + + pushq %rax # 64(%rsp) + pushq %rcx # 56(%rsp) + pushq %rdx # 48(%rsp) + pushq %rsi # 40(%rsp) + pushq %rdi # 32(%rsp) + pushq %r8 # 24(%rsp) + pushq %r9 # 16(%rsp) + pushq %r10 # 8(%rsp) + pushq %r11 # 0(%rsp) + + cmpl $__KERNEL_CS,96(%rsp) + jne 10f + + leaq 88(%rsp),%rdi # Pointer to %rip + call early_fixup_exception + andl %eax,%eax + jnz 20f # Found an exception entry + +10: +#ifdef CONFIG_EARLY_PRINTK + GET_CR2_INTO(%r9) # can clobber any volatile register if pv + movl 80(%rsp),%r8d # error code + movl 72(%rsp),%e |