diff options
Diffstat (limited to 'arch')
31 files changed, 761 insertions, 443 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 787e829b6f25..4a02cab105fd 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -135,7 +135,7 @@ config PPC select ARCH_HAS_STRICT_KERNEL_RWX if (PPC32 && !HIBERNATION) select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAS_UACCESS_FLUSHCACHE - select ARCH_HAS_UACCESS_MCSAFE if PPC64 + select ARCH_HAS_COPY_MC if PPC64 select ARCH_HAS_UBSAN_SANITIZE_ALL select ARCH_HAVE_NMI_SAFE_CMPXCHG select ARCH_KEEP_MEMBLOCK diff --git a/arch/powerpc/include/asm/string.h b/arch/powerpc/include/asm/string.h index 283552cd0e58..2aa0e31e6884 100644 --- a/arch/powerpc/include/asm/string.h +++ b/arch/powerpc/include/asm/string.h @@ -53,9 +53,7 @@ void *__memmove(void *to, const void *from, __kernel_size_t n); #ifndef CONFIG_KASAN #define __HAVE_ARCH_MEMSET32 #define __HAVE_ARCH_MEMSET64 -#define __HAVE_ARCH_MEMCPY_MCSAFE -extern int memcpy_mcsafe(void *dst, const void *src, __kernel_size_t sz); extern void *__memset16(uint16_t *, uint16_t v, __kernel_size_t); extern void *__memset32(uint32_t *, uint32_t v, __kernel_size_t); extern void *__memset64(uint64_t *, uint64_t v, __kernel_size_t); diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index 00699903f1ef..20a35373cafc 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -435,6 +435,32 @@ do { \ extern unsigned long __copy_tofrom_user(void __user *to, const void __user *from, unsigned long size); +#ifdef CONFIG_ARCH_HAS_COPY_MC +unsigned long __must_check +copy_mc_generic(void *to, const void *from, unsigned long size); + +static inline unsigned long __must_check +copy_mc_to_kernel(void *to, const void *from, unsigned long size) +{ + return copy_mc_generic(to, from, size); +} +#define copy_mc_to_kernel copy_mc_to_kernel + +static inline unsigned long __must_check +copy_mc_to_user(void __user *to, const void *from, unsigned long n) +{ + if (likely(check_copy_size(from, n, true))) { + if (access_ok(to, n)) { + allow_write_to_user(to, n); + n = copy_mc_generic((void *)to, from, n); + prevent_write_to_user(to, n); + } + } + + return n; +} +#endif + #ifdef __powerpc64__ static inline unsigned long raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) @@ -523,20 +549,6 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n) return ret; } -static __always_inline unsigned long __must_check -copy_to_user_mcsafe(void __user *to, const void *from, unsigned long n) -{ - if (likely(check_copy_size(from, n, true))) { - if (access_ok(to, n)) { - allow_write_to_user(to, n); - n = memcpy_mcsafe((void *)to, from, n); - prevent_write_to_user(to, n); - } - } - - return n; -} - unsigned long __arch_clear_user(void __user *addr, unsigned long size); static inline unsigned long clear_user(void __user *addr, unsigned long size) diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile index d66a645503eb..69a91b571845 100644 --- a/arch/powerpc/lib/Makefile +++ b/arch/powerpc/lib/Makefile @@ -39,7 +39,7 @@ obj-$(CONFIG_PPC_BOOK3S_64) += copyuser_power7.o copypage_power7.o \ memcpy_power7.o obj64-y += copypage_64.o copyuser_64.o mem_64.o hweight_64.o \ - memcpy_64.o memcpy_mcsafe_64.o + memcpy_64.o copy_mc_64.o ifndef CONFIG_PPC_QUEUED_SPINLOCKS obj64-$(CONFIG_SMP) += locks.o diff --git a/arch/powerpc/lib/memcpy_mcsafe_64.S b/arch/powerpc/lib/copy_mc_64.S index cb882d9a6d8a..88d46c471493 100644 --- a/arch/powerpc/lib/memcpy_mcsafe_64.S +++ b/arch/powerpc/lib/copy_mc_64.S @@ -50,7 +50,7 @@ err3; stb r0,0(r3) blr -_GLOBAL(memcpy_mcsafe) +_GLOBAL(copy_mc_generic) mr r7,r5 cmpldi r5,16 blt .Lshort_copy @@ -239,4 +239,4 @@ err1; stb r0,0(r3) 15: li r3,0 blr -EXPORT_SYMBOL_GPL(memcpy_mcsafe); +EXPORT_SYMBOL_GPL(copy_mc_generic); diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 7101ac64bb20..e876b3a087f9 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -75,7 +75,7 @@ config X86 select ARCH_HAS_PTE_DEVMAP if X86_64 select ARCH_HAS_PTE_SPECIAL select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 - select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE + select ARCH_HAS_COPY_MC if X86_64 select ARCH_HAS_SET_MEMORY select ARCH_HAS_SET_DIRECT_MAP select ARCH_HAS_STRICT_KERNEL_RWX diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index ee1d3c5834c6..27b5e2bc6a01 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -62,7 +62,7 @@ config EARLY_PRINTK_USB_XDBC You should normally say N here, unless you want to debug early crashes or need a very simple printk logging facility. -config MCSAFE_TEST +config COPY_MC_TEST def_bool n config EFI_PGT_DUMP diff --git a/arch/x86/include/asm/asm-prototypes.h b/arch/x86/include/asm/asm-prototypes.h index 5a42f9206138..51e2bf27cc9b 100644 --- a/arch/x86/include/asm/asm-prototypes.h +++ b/arch/x86/include/asm/asm-prototypes.h @@ -5,6 +5,7 @@ #include <asm/string.h> #include <asm/page.h> #include <asm/checksum.h> +#include <asm/mce.h> #include <asm-generic/asm-prototypes.h> diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h index 5c15f95b1ba7..0359cbbd0f50 100644 --- a/arch/x86/include/asm/asm.h +++ b/arch/x86/include/asm/asm.h @@ -135,6 +135,9 @@ # define _ASM_EXTABLE_UA(from, to) \ _ASM_EXTABLE_HANDLE(from, to, ex_handler_uaccess) +# define _ASM_EXTABLE_CPY(from, to) \ + _ASM_EXTABLE_HANDLE(from, to, ex_handler_copy) + # define _ASM_EXTABLE_FAULT(from, to) \ _ASM_EXTABLE_HANDLE(from, to, ex_handler_fault) @@ -160,6 +163,9 @@ # define _ASM_EXTABLE_UA(from, to) \ _ASM_EXTABLE_HANDLE(from, to, ex_handler_uaccess) +# define _ASM_EXTABLE_CPY(from, to) \ + _ASM_EXTABLE_HANDLE(from, to, ex_handler_copy) + # define _ASM_EXTABLE_FAULT(from, to) \ _ASM_EXTABLE_HANDLE(from, to, ex_handler_fault) diff --git a/arch/x86/include/asm/copy_mc_test.h b/arch/x86/include/asm/copy_mc_test.h new file mode 100644 index 000000000000..e4991ba96726 --- /dev/null +++ b/arch/x86/include/asm/copy_mc_test.h @@ -0,0 +1,75 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _COPY_MC_TEST_H_ +#define _COPY_MC_TEST_H_ + +#ifndef __ASSEMBLY__ +#ifdef CONFIG_COPY_MC_TEST +extern unsigned long copy_mc_test_src; +extern unsigned long copy_mc_test_dst; + +static inline void copy_mc_inject_src(void *addr) +{ + if (addr) + copy_mc_test_src = (unsigned long) addr; + else + copy_mc_test_src = ~0UL; +} + +static inline void copy_mc_inject_dst(void *addr) +{ + if (addr) + copy_mc_test_dst = (unsigned long) addr; + else + copy_mc_test_dst = ~0UL; +} +#else /* CONFIG_COPY_MC_TEST */ +static inline void copy_mc_inject_src(void *addr) +{ +} + +static inline void copy_mc_inject_dst(void *addr) +{ +} +#endif /* CONFIG_COPY_MC_TEST */ + +#else /* __ASSEMBLY__ */ +#include <asm/export.h> + +#ifdef CONFIG_COPY_MC_TEST +.macro COPY_MC_TEST_CTL + .pushsection .data + .align 8 + .globl copy_mc_test_src + copy_mc_test_src: + .quad 0 + EXPORT_SYMBOL_GPL(copy_mc_test_src) + .globl copy_mc_test_dst + copy_mc_test_dst: + .quad 0 + EXPORT_SYMBOL_GPL(copy_mc_test_dst) + .popsection +.endm + +.macro COPY_MC_TEST_SRC reg count target + leaq \count(\reg), %r9 + cmp copy_mc_test_src, %r9 + ja \target +.endm + +.macro COPY_MC_TEST_DST reg count target + leaq \count(\reg), %r9 + cmp copy_mc_test_dst, %r9 + ja \target +.endm +#else +.macro COPY_MC_TEST_CTL +.endm + +.macro COPY_MC_TEST_SRC reg count target +.endm + +.macro COPY_MC_TEST_DST reg count target +.endm +#endif /* CONFIG_COPY_MC_TEST */ +#endif /* __ASSEMBLY__ */ +#endif /* _COPY_MC_TEST_H_ */ diff --git a/arch/x86/include/asm/extable.h b/arch/x86/include/asm/extable.h index d8c2198d543b..1f0cbc52937c 100644 --- a/arch/x86/include/asm/extable.h +++ b/arch/x86/include/asm/extable.h @@ -29,10 +29,17 @@ struct pt_regs; (b)->handler = (tmp).handler - (delta); \ } while (0) +enum handler_type { + EX_HANDLER_NONE, + EX_HANDLER_FAULT, + EX_HANDLER_UACCESS, + EX_HANDLER_OTHER +}; + extern int fixup_exception(struct pt_regs *regs, int trapnr, unsigned long error_code, unsigned long fault_addr); extern int fixup_bug(struct pt_regs *regs, int trapnr); -extern bool ex_has_fault_handler(unsigned long ip); +extern enum handler_type ex_get_fault_handler_type(unsigned long ip); extern void early_fixup_exception(struct pt_regs *regs, int trapnr); #endif diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index cf503824529c..a0f147893a04 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -136,9 +136,24 @@ #define MCE_HANDLED_NFIT BIT_ULL(3) #define MCE_HANDLED_EDAC BIT_ULL(4) #define MCE_HANDLED_MCELOG BIT_ULL(5) + +/* + * Indicates an MCE which has happened in kernel space but from + * which the kernel can recover simply by executing fixup_exception() + * so that an error is returned to the caller of the function that + * hit the machine check. + */ #define MCE_IN_KERNEL_RECOV BIT_ULL(6) /* + * Indicates an MCE that happened in kernel space while copying data + * from user. In this case fixup_exception() gets the kernel to the + * error exit for the copy function. Machine check handler can then + * treat it like a fault taken in user mode. + */ +#define MCE_IN_KERNEL_COPYIN BIT_ULL(7) + +/* * This structure contains all data related to the MCE log. Also * carries a signature to make it easier to find from external * debugging tools. Each entry is only valid when its finished flag @@ -174,6 +189,15 @@ extern void mce_unregister_decode_chain(struct notifier_block *nb); extern int mce_p5_enabled; +#ifdef CONFIG_ARCH_HAS_COPY_MC +extern void enable_copy_mc_fragile(void); +unsigned long __must_check copy_mc_fragile(void *dst, const void *src, unsigned cnt); +#else +static inline void enable_copy_mc_fragile(void) +{ +} +#endif + #ifdef CONFIG_X86_MCE int mcheck_init(void); void mcheck_cpu_init(struct cpuinfo_x86 *c); @@ -200,12 +224,8 @@ void mce_setup(struct mce *m); void mce_log(struct mce *m); DECLARE_PER_CPU(struct device *, mce_device); -/* - * Maximum banks number. - * This is the limit of the current register layout on - * Intel CPUs. - */ -#define MAX_NR_BANKS 32 +/* Maximum number of MCA banks per CPU. */ +#define MAX_NR_BANKS 64 #ifdef CONFIG_X86_MCE_INTEL void mce_intel_feature_init(struct cpuinfo_x86 *c); @@ -328,7 +348,6 @@ enum smca_bank_types { struct smca_hwid { unsigned int bank_type; /* Use with smca_bank_types for easy indexing. */ u32 hwid_mcatype; /* (hwid,mcatype) tuple */ - u32 xec_bitmap; /* Bitmap of valid ExtErrorCodes; current max is 21. */ u8 count; /* Number of instances. */ }; diff --git a/arch/x86/include/asm/mcsafe_test.h b/arch/x86/include/asm/mcsafe_test.h deleted file mode 100644 index eb59804b6201..000000000000 --- a/arch/x86/include/asm/mcsafe_test.h +++ /dev/null @@ -1,75 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _MCSAFE_TEST_H_ -#define _MCSAFE_TEST_H_ - -#ifndef __ASSEMBLY__ -#ifdef CONFIG_MCSAFE_TEST -extern unsigned long mcsafe_test_src; -extern unsigned long mcsafe_test_dst; - -static inline void mcsafe_inject_src(void *addr) -{ - if (addr) - mcsafe_test_src = (unsigned long) addr; - else - mcsafe_test_src = ~0UL; -} - -static inline void mcsafe_inject_dst(void *addr) -{ - if (addr) - mcsafe_test_dst = (unsigned long) addr; - else - mcsafe_test_dst = ~0UL; -} -#else /* CONFIG_MCSAFE_TEST */ -static inline void mcsafe_inject_src(void *addr) -{ -} - -static inline void mcsafe_inject_dst(void *addr) -{ -} -#endif /* CONFIG_MCSAFE_TEST */ - -#else /* __ASSEMBLY__ */ -#include <asm/export.h> - -#ifdef CONFIG_MCSAFE_TEST -.macro MCSAFE_TEST_CTL - .pushsection .data - .align 8 - .globl mcsafe_test_src - mcsafe_test_src: - .quad 0 - EXPORT_SYMBOL_GPL(mcsafe_test_src) - .globl mcsafe_test_dst - mcsafe_test_dst: - .quad 0 - EXPORT_SYMBOL_GPL(mcsafe_test_dst) - .popsection -.endm - -.macro MCSAFE_TEST_SRC reg count target - leaq \count(\reg), %r9 - cmp mcsafe_test_src, %r9 - ja \target -.endm - -.macro MCSAFE_TEST_DST reg count target - leaq \count(\reg), %r9 - cmp mcsafe_test_dst, %r9 - ja \target -.endm -#else -.macro MCSAFE_TEST_CTL -.endm - -.macro MCSAFE_TEST_SRC reg count target -.endm - -.macro MCSAFE_TEST_DST reg count target -.endm -#endif /* CONFIG_MCSAFE_TEST */ -#endif /* __ASSEMBLY__ */ -#endif /* _MCSAFE_TEST_H_ */ diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h index 75314c3dbe47..6e450827f677 100644 --- a/arch/x86/include/asm/string_64.h +++ b/arch/x86/include/asm/string_64.h @@ -82,38 +82,6 @@ int strcmp(const char *cs, const char *ct); #endif -#define __HAVE_ARCH_MEMCPY_MCSAFE 1 -__must_check unsigned long __memcpy_mcsafe(void *dst, const void *src, - size_t cnt); -DECLARE_STATIC_KEY_FALSE(mcsafe_key); - -/** - * memcpy_mcsafe - copy memory with indication if a machine check happened - * - * @dst: destination address - * @src: source address - * @cnt: number of bytes to copy - * - * Low level memory copy function that catches machine checks - * We only call into the "safe" function on systems that can - * actually do machine check recovery. Everyone else can just - * use memcpy(). - * - * Return 0 for success, or number of bytes not copied if there was an - * exception. - */ -static __always_inline __must_check unsigned long -memcpy_mcsafe(void *dst, const void *src, size_t cnt) -{ -#ifdef CONFIG_X86_MCE - if (static_branch_unlikely(&mcsafe_key)) - return __memcpy_mcsafe(dst, src, cnt); - else -#endif - memcpy(dst, src, cnt); - return 0; -} - #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE #define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1 void __memcpy_flushcache(void *dst, const void *src, size_t cnt); diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 714b1a30e7b0..df0b7bfc1234 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -35,6 +35,8 @@ extern int panic_on_unrecovered_nmi; void math_emulate(struct math_emu_info *); +bool fault_in_kernel_space(unsigned long address); + #ifdef CONFIG_VMAP_STACK void __noreturn handle_stack_overflow(const char *message, struct pt_regs *regs, diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index ecefaffd15d4..eff7fb847149 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -455,6 +455,15 @@ extern __must_check long strnlen_user(const char __user *str, long n); unsigned long __must_check clear_user(void __user *mem, unsigned long len); unsigned long __must_check __clear_user(void __user *mem, unsigned long len); +#ifdef CONFIG_ARCH_HAS_COPY_MC +unsigned long __must_check +copy_mc_to_kernel(void *to, const void *from, unsigned len); +#define copy_mc_to_kernel copy_mc_to_kernel + +unsigned long __must_check +copy_mc_to_user(void *to, const void *from, unsigned len); +#endif + /* * movsl can be slow when source and dest are not both 8-byte aligned */ diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index bc10e3dc64fe..e7265a552f4f 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -47,22 +47,6 @@ copy_user_generic(void *to, const void *from, unsigned len) } static __always_inline __must_check unsigned long -copy_to_user_mcsafe(void *to, const void *from, unsigned len) -{ - unsigned long ret; - - __uaccess_begin(); - /* - * Note, __memcpy_mcsafe() is explicitly used since it can - * handle exceptions / faults. memcpy_mcsafe() may fall back to - * memcpy() which lacks this handling. - */ - ret = __memcpy_mcsafe(to, from, len); - __uaccess_end(); - return ret; -} - -static __always_inline __must_check unsigned long raw_copy_from_user(void *dst, const void __user *src, unsigned long size) { return copy_user_generic(dst, (__force void *)src, size); @@ -102,8 +86,4 @@ __copy_from_user_flushcache(void *dst, const void __user *src, unsigned size) kasan_check_write(dst, size); return __copy_user_flushcache(dst, src, size); } - -unsigned long -mcsafe_handle_tail(char *to, char *from, unsigned len); - #endif /* _ASM_X86_UACCESS_64_H */ diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c index 99be063fcb1b..0c6b02dd744c 100644 --- a/arch/x86/kernel/cpu/mce/amd.c +++ b/arch/x86/kernel/cpu/mce/amd.c @@ -132,49 +132,49 @@ static enum smca_bank_types smca_get_bank_type(unsigned int bank) } static struct smca_hwid smca_hwid_mcatypes[] = { - /* { bank_type, hwid_mcatype, xec_bitmap } */ + /* { bank_type, hwid_mcatype } */ /* Reserved type */ - { SMCA_RESERVED, HWID_MCATYPE(0x00, 0x0), 0x0 }, + { SMCA_RESERVED, HWID_MCATYPE(0x00, 0x0) }, /* ZN Core (HWID=0xB0) MCA types */ - { SMCA_LS, HWID_MCATYPE(0xB0, 0x0), 0x1FFFFF }, - { SMCA_LS_V2, HWID_MCATYPE(0xB0, 0x10), 0xFFFFFF }, - { SMCA_IF, HWID_MCATYPE(0xB0, 0x1), 0x3FFF }, - { SMCA_L2_CACHE, HWID_MCATYPE(0xB0, 0x2), 0xF }, - { SMCA_DE, HWID_MCATYPE(0xB0, 0x3), 0x1FF }, + { SMCA_LS, HWID_MCATYPE(0xB0, 0x0) }, + { SMCA_LS_V2, HWID_MCATYPE(0xB0, 0x10) }, + { SMCA_IF, HWID_MCATYPE(0xB0, 0x1) }, + { SMCA_L2_CACHE, HWID_MCATYPE(0xB0, 0x2) }, + { SMCA_DE, HWID_MCATYPE(0xB0, 0x3) }, /* HWID 0xB0 MCATYPE 0x4 is Reserved */ - { SMCA_EX, HWID_MCATYPE(0xB0, 0x5), 0xFFF }, - { SMCA_FP, HWID_MCATYPE(0xB0, 0x6), 0x7F }, - { SMCA_L3_CACHE, HWID_MCATYPE(0xB0, 0x7), 0xFF }, + { SMCA_EX, HWID_MCATYPE(0xB0, 0x5) }, + { SMCA_FP, HWID_MCATYPE(0xB0, 0x6) }, + { SMCA_L3_CACHE, HWID_MCATYPE(0xB0, 0x7) }, /* Data Fabric MCA types */ - { SMCA_CS, HWID_MCATYPE(0x2E, 0x0), 0x1FF }, - { SMCA_PIE, HWID_MCATYPE(0x2E, 0x1), 0x1F }, - { SMCA_CS_V2, HWID_MCATYPE(0x2E, 0x2), 0x3FFF }, + { SMCA_CS, HWID_MCATYPE(0x2E, 0x0) }, + { SMCA_PIE, HWID_MCATYPE(0x2E, 0x1) }, + { SMCA_CS_V2, HWID_MCATYPE(0x2E, 0x2) }, /* Unified Memory Controller MCA type */ - { SMCA_UMC, HWID_MCATYPE(0x96, 0x0), 0xFF }, + { SMCA_UMC, HWID_MCATYPE(0x96, 0x0) }, /* Parameter Block MCA type */ - { SMCA_PB, HWID_MCATYPE(0x05, 0x0), 0x1 }, + { SMCA_PB, HWID_MCATYPE(0x05, 0x0) }, /* Platform Security Processor MCA type */ - { SMCA_PSP, HWID_MCATYPE(0xFF, 0x0), 0x1 }, - { SMCA_PSP_V2, HWID_MCATYPE(0xFF, 0x1), 0x3FFFF }, + { SMCA_PSP, HWID_MCATYPE(0xFF, 0x0) }, + { SMCA_PSP_V2, HWID_MCATYPE(0xFF, 0x1) }, /* System Management Unit MCA type */ - { SMCA_SMU, HWID_MCATYPE(0x01, 0x0), 0x1 }, - { SMCA_SMU_V2, HWID_MCATYPE(0x01, 0x1), 0x7FF }, + { SMCA_SMU, HWID_MCATYPE(0x01, 0x0) }, + { SMCA_SMU_V2, HWID_MCATYPE(0x01, 0x1) }, /* Microprocessor 5 Unit MCA type */ - { SMCA_MP5, HWID_MCATYPE(0x01, 0x2), 0x3FF }, + { SMCA_MP5, HWID_MCATYPE(0x01, 0x2) }, /* Northbridge IO Unit MCA type */ - { SMCA_NBIO, HWID_MCATYPE(0x18, 0x0), 0x1F }, + { SMCA_NBIO, HWID_MCATYPE(0x18, 0x0) }, /* PCI Express Unit MCA type */ - { SMCA_PCIE, HWID_MCATYPE(0x46, 0x0), 0x1F }, + { SMCA_PCIE, HWID_MCATYPE(0x46, 0x0) }, }; struct smca_bank smca_banks[MAX_NR_BANKS]; diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index fc4f8c04bdb5..1c08cb9eb9f6 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -40,7 +40,6 @@ #include <linux/debugfs.h> #include <linux/irq_work.h> #include <linux/export.h> -#include <linux/jump_label.h> #include <linux/set_memory.h> #include <linux/sync_core.h> #include <linux/task_work.h> @@ -373,42 +372,105 @@ static int msr_to_offset(u32 msr) return -1; } +__visible bool ex_handler_rdmsr_fault(const struct exception_table_entry *fixup, + struct pt_regs *regs, int trapnr, + unsigned long error_code, + unsigned long fault_addr) +{ + pr_emerg("MSR access error: RDMSR from 0x%x at rIP: 0x%lx (%pS)\n", + (unsigned int)regs->cx, regs->ip, (void *)regs->ip); + + show_stack_regs(regs); + + panic("MCA architectural violation!\n"); + + while (true) + cpu_relax(); + + return true; +} + /* MSR access wrappers used for error injection */ -static u64 mce_rdmsrl(u32 msr) +static noinstr u64 mce_rdmsrl(u32 msr) { - u64 v; + DECLARE_ARGS(val, low, high); if (__this_cpu_read(injectm.finished)) { - int offset = msr_to_offset(msr); + int offset; + u64 ret; + + instrumentation_begin(); + offset = msr_to_offset(msr); if (offset < 0) - return 0; - return *(u64 *)((char *)this_cpu_ptr(&injectm) + offset); - } + ret = 0; + else + ret = *(u64 *)((char *)this_cpu_ptr(&injectm) + offset); - if (rdmsrl_safe(msr, &v)) { - WARN_ONCE(1, "mce: Unable to read MSR 0x%x!\n", msr); - /* - * Return zero in case the access faulted. This should - * not happen normally but can happen if the CPU does - * something weird, or if the code is buggy. - */ - v = 0; + instrumentation_end(); + + return ret; } - return v; + /* + * RDMSR on MCA MSRs should not fault. If they do, this is very much an + * architectural violation and needs to be reported to hw vendor. Panic + * the box to not allow any further progress. + */ + asm volatile("1: rdmsr\n" + "2:\n" + _ASM_EXTABLE_HANDLE(1b, 2b, ex_handler_rdmsr_fault) + : EAX_EDX_RET(val, low, high) : "c" (msr)); + + + return EAX_EDX_VAL(val, low, high); +} + +__visible bool ex_handler_wrmsr_fault(const struct exception_table_entry *fixup, + struct pt_regs *regs, int trapnr, + unsigned long error_code, + unsigned long fault_addr) +{ + pr_emerg("MSR access error: WRMSR to 0x%x (tried to write 0x%08x%08x) at rIP: 0x%lx (%pS)\n", + (unsigned int)regs->cx, (unsigned int)regs->dx, (unsigned int)regs->ax, + regs->ip, (void *)regs->ip); + + show_stack_regs(regs); + + panic("MCA architectural violation!\n"); + + while (true) + cpu_relax(); + + return true; } -static void mce_wrmsrl(u32 msr, u64 v) +static noinstr void mce_wrmsrl(u32 msr, u64 v) { + u32 low, high; + if (__this_cpu_read(injectm.finished)) { - int offset = msr_to_offset(msr); + int offset; + + instrumentation_begin(); + offset = msr_to_offset(msr); if (offset >= 0) *(u64 *)((char *)this_cpu_ptr(&injectm) + offset) = v; + + instrumentation_end(); + return; } - wrmsrl(msr, v); + + low = (u32)v; + high = (u32)(v >> 32); + + /* See comment in mce_rdmsrl() */ + asm volatile("1: wrmsr\n" + "2:\n" + _ASM_EXTABLE_HANDLE(1b, 2b, ex_handler_wrmsr_fault) + : : "c" (msr), "a"(low), "d" (high) : "memory"); } /* @@ -745,7 +807,7 @@ log_it: goto clear_it; mce_read_aux(&m, i); - m.severity = mce_severity(&m, mca_cfg.tolerant, NULL, false); + m.severity = mce_severity(&m, NULL, mca_cfg.tolerant, NULL, false); /* * Don't get the IP here because it's unlikely to * have anything to do with the actual error location. @@ -794,7 +856,7 @@ static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp, quirk_no_way_out(i, m, regs); m->bank = i; - if (mce_severity(m, mca_cfg.tolerant, &tmp, true) >= MCE_PANIC_SEVERITY) { + if (mce_severity(m, regs, mca_cfg.tolerant, &tmp, true) >= MCE_PANIC_SEVERITY) { mce_read_aux(m, i); *msg = tmp; return 1; @@ -872,7 +934,6 @@ static void mce_reign(void) struct mce *m = NULL; int global_worst = 0; char *msg = NULL; - char *nmsg = NULL; /* * This CPU is the Monarch and the other CPUs have run @@ -880,12 +941,10 @@ static void mce_reign(void) * Grade the severity of the errors of all the CPUs. */ for_each_possible_cpu(cpu) { - int severity = mce_severity(&per_cpu(mces_seen, cpu), - mca_cfg.tolerant, - &nmsg, true); - if (severity > global_worst) { - msg = nmsg; - global_worst = severity; + struct mce *mtmp = &per_cpu(mces_seen, cpu); + + if (mtmp->severity > global_worst) { + global_worst = mtmp->severity; m = &per_cpu(mces_seen, cpu); } } @@ -895,8 +954,11 @@ static void mce_reign(void) * This dumps all the mces in the log buffer and stops the * other CPUs. */ - if (m && global_worst >= MCE_PANIC_SEVERITY && mca_cfg.tolerant < 3) + if (m && global_worst >= MCE_PANIC_SEVERITY && mca_cfg.tolerant < 3) { + /* call mce_severity() to get "msg" for panic */ + mce_severity(m, NULL, mca_cfg.tolerant, &msg, true); mce_panic("Fatal machine check", m, msg); + } /* * For UC somewhere we let the CPU who detects it handle it. @@ -1105,7 +1167,7 @@ static noinstr bool mce_check_crashing_cpu(void) return false; } -static void __mc_scan_banks(struct mce *m, struct mce *final, +static void __mc_scan_banks(struct mce *m, struct pt_regs *regs, struct mce *final, unsigned long *toclear, unsigned long *valid_banks, int no_way_out, int *worst) { @@ -1140,7 +1202,7 @@ static void __mc_scan_banks(struct mce *m, struct mce *final, /* Set taint even when machine check was not enabled. */ add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE); - severity = mce_severity(m, cfg->tolerant, NULL, true); + severity = mce_severity(m, regs, cfg->tolerant, NULL, true); /* * When machine check was for corrected/deferred handler don't @@ -1188,13 +1250,34 @@ static void kill_me_maybe(struct callback_head *cb) if (!p->mce_ripv) flags |= MF_MUST_KILL; - if (!memory_failure(p->mce_addr >> PAGE_SHIFT, flags)) { + if (!memory_failure(p->mce_addr >> PAGE_SHIFT, flags) && + !(p->mce_kflags & MCE_IN_KERNEL_COPYIN)) { set_mce_nospec(p->mce_addr >> PAGE_SHIFT, p->mce_whole_page); + sync_core(); return; } - pr_err("Memory error not recovered"); - kill_me_now(cb); + if (p->mce_vaddr != (void __user *)-1l) { + force_sig_mceerr(BUS_MCEERR_AR, p->mce_vaddr, PAGE_SHIFT); + } else { + pr_err("Memory error not recovered"); + kill_me_now(cb); + } +} + +static void queue_task_work(struct mce *m, int kill_it) +{ + current->mce_addr = m->addr; + current->mce_kflags = m->kflags; + current->mce_ripv = !!(m->mcgstatus & MCG_STATUS_RIPV); + current->mce_whole_page = whole_page(m); + + if (kill_it) + current->mce_kill_me.func = kill_me_now; + else + current->mce_kill_me.func = kill_me_maybe; + + task_work_add(current, ¤t->mce_kill_me, true); } /* @@ -1291,7 +1374,7 @@ noinstr void do_machine_check(struct pt_regs *regs) order = mce_start(&no_way_out); } - __mc_scan_banks(&m, final, toclear, valid_banks, no_way_out, &worst); + __mc_scan_banks(&m, regs, final, toclear, valid_banks, no_way_out, &worst); if (!no_way_out) mce_clear_state(toclear); @@ -1313,7 +1396,7 @@ noinstr void do_machine_check(struct pt_regs *regs) * make sure we have the right "msg". */ if (worst >= MCE_PANIC_SEVERITY && mca_cfg.tolerant < 3) { - mce_severity(&m, cfg->tolerant, &msg, true); + mce_severity(&m, regs, cfg->tolerant, &msg, true); mce_panic("Local fatal machine check!", &m, msg); } } @@ -1330,25 +1413,16 @@ noinstr void do_machine_check(struct pt_regs *regs) if (worst > 0) irq_work_queue(&mce_irq_work); - mce_wrmsrl(MSR_IA32_MCG_STATUS, 0); - - sync_core(); - if (worst != MCE_AR_SEVERITY && !kill_it) - return; + goto out; /* Fault was in user mode and we need to take some action */ if ((m.cs & 3) == 3) { /* If this triggers there is no way to recover. Die hard. */ BUG_ON(!on_thread_stack() || !user_mode(regs)); - current->mce_addr = m.addr; - current->mce_ripv = !!(m.mcgstatus & MCG_STATUS_RIPV); - current->mce_whole_page = whole_page(&m); - current->mce_kill_me.func = kill_me_maybe; - if (kill_it) - current->mce_kill_me.func = kill_me_now; - task_work_add(current, ¤t->mce_kill_me, true); + queue_task_work(&m, kill_it); + } else { /* * Handle an MCE which has happened in kernel space but from @@ -1363,7 +1437,12 @@ noinstr void do_machine_check(struct pt_regs *regs) if (!fixup_exception(regs, X86_TRAP_MC, 0, 0)) mce_panic("Failed kernel mode recovery", &m, msg); } + + if (m.kflags & MCE_IN_KERNEL_COPYIN) + queue_task_work(&m, kill_it); } +out: + mce_wrmsrl(MSR_IA32_MCG_STATUS, 0); } EXPORT_SYMBOL_GPL(do_machine_check); @@ -2064,7 +2143,7 @@ void mce_disable_bank(int bank) and older. * mce=nobootlog Don't log MCEs from before booting. * mce=bios_cmci_threshold Don't program the CMCI threshold - * mce=recovery force enable memcpy_mcsafe() + * mce=recovery force enable copy_mc_fragile() */ static int __init mcheck_enable(char *str) { @@ -2672,13 +2751,10 @@ static void __init mcheck_debugfs_init(void) static void __init mcheck_debugfs_init(void) { } #endif -DEFINE_STATIC_KEY_FALSE(mcsafe_key); -EXPORT_SYMBOL_GPL(mcsafe_key); - static int __init mcheck_late_init(void) { if (mca_cfg.recovery) - static_branch_inc(&mcsafe_key); + enable_copy_mc_fragile(); mcheck_debugfs_init(); diff --git a/arch/x86/kernel/cpu/mce/dev-mcelog.c b/arch/x86/kernel/cpu/mce/dev-mcelog.c index 03e51053592a..100fbeebdc72 100644 --- a/arch/x86/kernel/cpu/mce/dev-mcelog.c +++ b/arch/x86/kernel/cpu/mce/dev-mcelog.c @@ -67,7 +67,9 @@ static int dev_mce_log(struct notifier_block *nb, unsigned long val, unlock: mutex_unlock(&mce_chrdev_read_mutex); - mce->kflags |= MCE_HANDLED_MCELOG; + if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) + mce->kflags |= MCE_HANDLED_MCELOG; + return NOTIFY_OK; } diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h index 6473070b5da4..88dcc79cfb07 100644 --- a/arch/x86/kernel/cpu/mce/internal.h +++ b/arch/x86/kernel/cpu/mce/internal.h @@ -38,7 +38,8 @@ int mce_gen_pool_add(struct mce *mce); int mce_gen_pool_init(void); struct llist_node *mce_gen_pool_prepare_records(void); -extern int (*mce_severity)(struct mce *a, int tolerant, char **msg, bool is_excp); +extern int (*mce_severity)(struct mce *a, struct pt_regs *regs, + int tolerant, char **msg, bool is_excp); struct dentry *mce_get_debugfs_dir(void); extern mce_banks_t mce_banks_ce_disabled; @@ -185,4 +186,14 @@ extern bool amd_filter_mce(struct mce *m); static inline bool amd_filter_mce(struct mce *m) { return false; }; #endif +__visible bool ex_handler_rdmsr_fault(const struct exception_table_entry *fixup, + struct pt_regs *regs, int trapnr, + unsigned long error_code, + unsigned long fault_addr); + +__visible bool ex_handler_wrmsr_fault(const struct exception_table_entry *fixup, + struct pt_regs *regs, int trapnr, + unsigned long error_code, + unsigned long fault_addr); + #endif /* __X86_MCE_INTERNAL_H__ */ diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c index e1da619add19..83df991314c5 100644 --- a/arch/x86/kernel/cpu/mce/severity.c +++ b/arch/x86/kernel/cpu/mce/severity.c @@ -9,9 +9,14 @@ #include <linux/seq_file.h> #include <linux/init.h> #include <linux/debugfs.h> -#include <asm/mce.h> #include <linux/uaccess.h> +#include <asm/mce.h> +#include <asm/intel-family.h> +#include <asm/traps.h> +#include <asm/insn.h> +#include <asm/insn-eval.h> + #include "internal.h" /* @@ -40,9 +45,14 @@ static struct severity { unsigned char context; unsigned char excp; unsigned char covered; + unsigned char cpu_model; + unsigned char cpu_minstepping; + unsigned char bank_lo, bank_hi; char *msg; } severities[] = { #define MCESEV(s, m, c...) { .sev = MCE_ ## s ## _SEVERITY, .msg = m, ## c } +#define BANK_RANGE(l, h) .bank_lo = l, .bank_hi = h +#define MODEL_STEPPING(m, s) .cpu_model = m, .cpu_minstepping = s #define KERNEL .context = IN_KERNEL #define USER .context = IN_USER #define KERNEL_RECOV .context = IN_KERNEL_RECOV @@ -90,14 +100,9 @@ static struct severity { EXCP, KERNEL_RECOV, MCGMASK(MCG_STATUS_RIPV, 0) ), MCESEV( - DEFERRED, "Deferred error", - NOSER, MASK(MCI_STATUS_UC|MCI_STATUS_DEFERRED|MCI_STATUS_POISON, MCI_STATUS_DEFERRED) - ), - MCESEV( KEEP, "Corrected error", NOSER, BITCLR(MCI_STATUS_UC) ), - /* * known AO MCACODs reported via MCE or CMC: * @@ -113,6 +118,18 @@ static struct severity { AO, "Action optional: last level cache writeback error", SER, MASK(MCI_UC_AR|MCACOD, MCI_STATUS_UC|MCACOD_L3WB) ), + /* + * Quirk for Skylake/Cascade Lake. Patrol scrubber may be configured + * to report uncorrected errors using CMCI with a special signature. + * UC=0, MSCOD=0x0010, MCACOD=binary(000X 0000 1100 XXXX) reported + * in one of the memory controller banks. + * Set severity to "AO" for same action as normal patrol scrub error. + */ + MCESEV( + AO, "Uncorrected Patrol Scrub Error", + SER, MASK(MCI_STATUS_UC|MCI_ADDR|0xffffeff0, MCI_ADDR|0x001000c0), + MODEL_STEPPING(INTEL_FAM6_SKYLAKE_X, 4), BANK_RANGE(13, 18) + ), /* ignore OVER for UCNA */ MCESEV( @@ -198,6 +215,47 @@ static struct severity { #define mc_recoverable(mcg) (((mcg) & (MCG_STATUS_RIPV|MCG_STATUS_EIPV)) == \ (MCG_STATUS_RIPV|MCG_STATUS_EIPV)) +static bool is_copy_from_user(struct pt_regs *regs) +{ + u8 insn_buf[MAX_INSN_SIZE]; + struct insn insn; + unsigned long addr; + + if (copy_from_kernel_nofault(insn_buf, (void *)regs->ip, MAX_INSN_SIZE)) + return false; + + kernel_insn_init(&insn, insn_buf, MAX_INSN_SIZE); + insn_get_opcode(&insn); + if (!insn.opcode.got) + return false; + + switch (insn.opcode.value) { + /* MOV mem,reg */ + case 0x8A: case 0x8B: + /* MOVZ mem,reg */ + case 0xB60F: case 0xB70F: + insn_get_modrm(&insn); + insn_get_sib(&insn); + if (!insn.modrm.got || !insn.sib.got) + return false; + addr = (unsigned long)insn_get_addr_ref(&insn, regs); + break; + /* REP MOVS */ + case 0xA4: case 0xA5: + addr = regs->si; + break; + default: + return false; + } + + if (fault_in_kernel_space(addr)) + return false; + + current->mce_vaddr = (void __user *)addr; + + return true; +} + /* * If mcgstatus indicated that ip/cs on the stack were * no good, then "m->cs" will be zero and we will have @@ -209,15 +267,25 @@ static struct severity { * distinguish an exception taken in user from from one * taken in the kernel. */ -static int error_context(struct mce *m) +static int error_context(struct mce *m, struct pt_regs *regs) { + enum handler_type t; + if ((m->cs & 3) == 3) return IN_USER; + if (!mc_recoverable(m->mcgstatus)) + return IN_KERNEL; - if (mc_recoverable(m->mcgstatus) && ex_has_fault_handler(m->ip)) { + t = ex_get_fault_handler_type(m->ip); + if (t == EX_HANDLER_FAULT) { m->kflags |= MCE_IN_KERNEL_RECOV; return IN_KERNEL_RECOV; } + if (t == EX_HANDLER_UACCESS && regs && is_copy_from_user(regs)) { + m->kflags |= MCE_IN_KERNEL_RECOV; + m->kflags |= MCE_IN_KERNEL_COPYIN; + return IN_KERNEL_RECOV; + } return IN_KERNEL; } @@ -253,9 +321,10 @@ static int mce_severity_amd_smca(struct mce *m, enum context err_ctx) * See AMD Error Scope Hierarchy table in a newer BKDG. For example * 49125_15h_Models_30h-3Fh_BKDG.pdf, section "RAS Features" */ -static int mce_severity_amd(struct mce *m, int tolerant, char **msg, bool is_excp) +static int mce_severity_amd(struct mce *m, struct pt_regs *regs, int tolerant, + char **msg, bool is_excp) { - enum context ctx = error_context(m); + enum context ctx = error_context(m, regs); /* Processor Context Corrupt, no need to fumble too much, die! */ if (m->status & MCI_STATUS_PCC) @@ -305,10 +374,11 @@ static int mce_severity_amd(struct mce *m, int tolerant, char **msg, bool is_exc return MCE_KEEP_SEVERITY; } -static int mce_severity_intel(struct mce *m, int tolerant, char **msg, bool is_excp) +static int mce_severity_intel(struct mce *m, struct pt_regs *regs, + int tolerant, char **msg, bool is_excp) { enum exception excp = (is_excp ? EXCP_CONTEXT : NO_EXCP); - enum context ctx = error_context(m); + enum context ctx = error_context(m, regs); struct severity *s; for (s = severities;; s++) { @@ -324,6 +394,12 @@ static int mce_severity_intel(struct mce *m, int tolerant, char **msg, bool is_e continue; if (s->excp && excp != s->excp) continue; + if (s->cpu_model && boot_cpu_data.x86_model != s->cpu_model) + continue; + if (s->cpu_minstepping && boot_cpu_data.x86_stepping < s->cpu_minstepping) + continue; + if (s->bank_lo && (m->bank < s->bank_lo || m->bank > s->bank_hi)) + continue; if (msg) *msg = s->msg; s->covered = 1; @@ -336,7 +412,7 @@ static int mce_severity_intel(struct mce *m, int tolerant, char **msg, bool is_e } /* Default to mce_severity_intel */ -int (*mce_severity)(struct mce *m, int tolerant, char **msg, bool is_excp) = +int (*mce_severity)(struct mce *m, struct pt_regs *regs, int tolerant, char **msg, bool is_excp) = mce_severity_intel; void __init mcheck_vendor_init_severity(void) diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c index 1b10717c9321..6d0df6a58873 100644 --- a/arch/x86/kernel/quirks.c +++ b/arch/x86/kernel/quirks.c @@ -8,6 +8,7 @@ #include <asm/hpet.h> #include <asm/setup.h> +#include <asm/mce.h> #if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI) @@ -624,10 +625,6 @@ static void amd_disable_seq_and_redirect_scrub(struct pci_dev *dev) DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3, amd_disable_seq_and_redirect_scrub); -#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE) -#include <linux/jump_label.h> -#include <asm/string_64.h> - /* Ivy Bridge, Haswell, Broadwell */ static void quirk_intel_brickland_xeon_ras_cap(struct pci_dev *pdev) { @@ -636,7 +633,7 @@ static void quirk_intel_brickland_xeon_ras_cap(struct pci_dev *pdev) pci_read_config_dword(pdev, 0x84, &capid0); if (capid0 & 0x10) - static_branch_inc(&mcsafe_key); + enable_copy_mc_fragile(); } /* Skylake */ @@ -653,7 +650,7 @@ static void quirk_intel_purley_xeon_ras_cap(struct pci_dev *pdev) * enabled, so memory machine check recovery is also enabled. */ if ((capid0 & 0xc0) == 0xc0 || (capid5 & 0x1e0)) - static_branch_inc(&mcsafe_key); + enable_copy_mc_fragile(); } DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x0ec3, quirk_intel_brickland_xeon_ras_cap); @@ -661,7 +658,6 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2fc0, quirk_intel_brickland_xeon_ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, quirk_intel_brickland_xeon_ras_cap); DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2083, quirk_intel_purley_xeon_ras_cap); #endif -#endif bool x86_apple_machine; EXPORT_SYMBOL(x86_apple_machine); diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index aa067859a70b..bad4dee4f0e4 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -44,6 +44,7 @@ obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o lib-y := delay.o misc.o cmdline.o cpu.o lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o lib-y += memcpy_$(BITS).o +lib-$(CONFIG_ARCH_HAS_COPY_MC) += copy_mc.o copy_mc_64.o lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o lib-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o diff --git a/arch/x86/lib/copy_mc.c b/arch/x86/lib/copy_mc.c new file mode 100644 index 000000000000..c13e8c9ee926 --- /dev/null +++ b/arch/x86/lib/copy_mc.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2016-2020 Intel Corporation. All rights reserved. */ + +#include <linux/jump_label.h> +#include <linux/uaccess.h> +#include <linux/export.h> +#include <linux/string.h> +#include <linux/types.h> + +#include <asm/mce.h> + +#ifdef CONFIG_X86_MCE +/* + * See COPY_MC_TEST for self-test of the copy_mc_fragile() + * implementation. + */ +static DEFINE_STATIC_KEY_FALSE(copy_mc_fragile_key); + +void enable_copy_mc_fragile(void) +{ + static_branch_inc(©_mc_fragile_key); +} +#define copy_mc_fragile_enabled (static_branch_unlikely(©_mc_fragile_key)) + +/* + * Similar to copy_user_handle_tail, probe for the write fault point, or + * source exception point. + */ +__visible notrace unsigned long +copy_mc_fragile_handle_tail(char *to, char *from, unsigned len) +{ + for (; len; --len, to++, from++) + if (copy_mc_fragile(to, from, 1)) + break; + return len; +} +#else +/* + * No point in doing careful copying, or consulting a static key when + * there is no #MC handler in the CONFIG_X86_MCE=n case. + */ +void enable_copy_mc_fragile(void) +{ +} +#define copy_mc_fragile_enabled (0) +#endif + +unsigned long copy_mc_enhanced_fast_string(void *dst, const void *src, unsigned len); + +/** + * copy_mc_to_kernel - memory copy that handles source exceptions + * + * @dst: destination address + * @src: source address + * @len: number of bytes to copy + * + * Call into the 'fragile' version on systems that benefit from avoiding + * corner case poison consumption scenarios, For example, accessing + * poison across 2 cachelines with a single instruction. Almost all + * other uses case can use copy_mc_enhanced_fast_string() for a fast + * recoverable copy, or fallback to plain memcpy. + * + * Return 0 for success, or number of bytes not copied if there was an + * exception. + */ +unsigned long __must_check copy_mc_to_kernel(void *dst, const void *src, unsigned len) +{ + if (copy_mc_fragile_enabled) + return copy_mc_fragile(dst, src, len); + if (static_cpu_has(X86_FEATURE_ERMS)) + return copy_mc_enhanced_fast_string(dst, src, len); + memcpy(dst, src, len); + return 0; +} +EXPORT_SYMBOL_GPL(copy_mc_to_kernel); + +unsigned long __must_check copy_mc_to_user(void *dst, const void *src, unsigned len) +{ + unsigned long ret; + + if (copy_mc_fragile_enabled) { + __uaccess_begin(); + ret = copy_mc_fragile(dst, src, len); + __uaccess_end(); + return ret; + } + + if (static_cpu_has(X86_FEATURE_ERMS)) { + __uaccess_begin(); + ret = copy_mc_enhanced_fast_string(dst, src, len); + __uaccess_end(); + return ret; + } + + return copy_user_generic(dst, src, len); +} diff --git a/arch/x86/lib/copy_mc_64.S b/arch/x86/lib/copy_mc_64.S new file mode 100644 index 000000000000..892d8915f609 --- /dev/null +++ b/arch/x86/lib/copy_mc_64.S @@ -0,0 +1,163 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright(c) 2016-2020 Intel Corporation. All rights reserved. */ + +#include <linux/linkage.h> +#include <asm/copy_mc_test.h> +#include <asm/export.h> +#include <asm/asm.h> + +#ifndef CONFIG_UML + +#ifdef CONFIG_X86_MCE +COPY_MC_TEST_CTL + +/* + * copy_mc_fragile - copy memory with indication if an exception / fault happened + * + * The 'fragile' version is opted into by platform quirks and takes + * pains to avoid unrecoverable corner cases like 'fast-string' + * instruction sequences, and consuming poison across a cacheline + * boundary. The non-fragile version is equivalent to memcpy() + * regardless of CPU machine-check-recovery capability. + */ +SYM_FUNC_START(copy_mc_fragile) + cmpl $8, %edx + /* Less than 8 bytes? Go to byte copy loop */ + jb .L_no_whole_words + + /* Check for bad alignment of source */ + testl $7, %esi + /* Already aligned */ + jz .L_8byte_aligned + + /* Copy one byte at a time until source is 8-byte aligned */ + movl %esi, %ecx + andl $7, %ecx + subl $8, %ecx + negl %ecx + subl %ecx, %edx +.L_read_leading_bytes: + movb (%rsi), %al + COPY_MC_TEST_SRC %rsi 1 .E_leading_bytes + COPY_MC_TEST_DST %rdi 1 .E_leading_bytes +.L_write_leading_bytes: + movb %al, (%rdi) + incq %rsi + incq %rdi + decl %ecx + jnz .L_read_leading_bytes + +.L_8byte_aligned: + movl %edx, %ecx + andl $7, %edx + shrl $3, %ecx + jz .L_no_whole_words + +.L_read_words: + movq (%rsi), %r8 + COPY_MC_TEST_SRC %rsi 8 .E_read_words + COPY_MC_TEST_DST %rdi 8 .E_write_words +.L_write_words: + movq %r8, (%rdi) + addq $8, %rsi + addq $8, %rdi + decl %ecx + jnz .L_read_words + + /* Any trailing bytes? */ +.L_no_whole_words: + andl %edx, %edx + jz .L_done_memcpy_trap + + /* Copy trailing bytes */ + movl %edx, %ecx +.L_read_trailing_bytes: + movb (%rsi), %al + COPY_MC_TEST_SRC %rsi 1 .E_trailing_bytes + COPY_MC_TEST_DST %rdi 1 .E_trailing_bytes +.L_write_trailing_bytes: + movb %al, (%rdi) + incq %rsi + incq %rdi + decl %ecx + jnz .L_read_trailing_bytes + + /* Copy successful. Return zero */ +.L_done_memcpy_trap: + xorl %eax, %eax +.L_done: + ret +SYM_FUNC_END(copy_mc_fragile) +EXPORT_SYMBOL_GPL(copy_mc_fragile) + + .section .fixup, "ax" + /* + * Return number of bytes not copied for any failure. Note that + * there is no "tail" handling since the source buffer is 8-byte + * aligned and poison is cacheline aligned. + */ +.E_read_words: + shll $3, %ecx +.E_leading_bytes: + addl %edx, %ecx +.E_trailing_bytes: + mov %ecx, %eax + jmp .L_done + + /* + * For write fault handling, given the destination is unaligned, + * we handle faults on multi-byte writes with a byte-by-byte + * copy up to the write-protected page. + */ +.E_write_words: + shll $3, %ecx + addl %edx, %ecx + movl %ecx, %edx + jmp copy_mc_fragile_handle_tail + + .previous + + _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes) + _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words) + _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes) + _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes) + _ASM_EXTABLE(.L_write_words, .E_write_words) + _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes) +#endif /* CONFIG_X86_MCE */ + +/* + * copy_mc_enhanced_fast_string - memory copy with exception handling + * + * Fast string copy + fault / exception handling. If the CPU does + * support machine check exception recovery, but does not support + * recovering from fast-string exceptions then this CPU needs to be + * added to the copy_mc_fragile_key set of quirks. Otherwise, absent any + * machine check recovery support this version should be no slower than + * standard memcpy. + */ +SYM_FUNC_START(copy_mc_enhanced_fast_string) + movq %rdi, %rax + movq %rdx, %rcx +.L_copy: + rep movsb + /* Copy successful. Return zero */ + xorl %eax, %eax + ret +SYM_FUNC_END(copy_mc_enhanced_fast_string) + + .section .fixup, "ax" +.E_copy: + /* + * On fault %rcx is updated such that the copy instruction could + * optionally be restarted at the fault position, i.e. it + * contains 'bytes remaining'. A non-zero return indicates error + * to copy_mc_generic() users, or indicate short transfers to + * user-copy routines. + */ + movq %rcx, %rax + ret + + .previous + + _ASM_EXTABLE_FAULT(.L_copy, .E_copy) +#endif /* !CONFIG_UML */ diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S index 816f128a6d52..77b9b2a3b5c8 100644 --- a/arch/x86/lib/copy_user_64.S +++ b/arch/x86/lib/copy_user_64.S @@ -15,6 +15,7 @@ #include <asm/asm.h> #include <asm/smap.h> #include <asm/export.h> +#include <asm/trapnr.h> .macro ALIGN_DESTINATION /* check for bad alignment of destination */ @@ -36,8 +37,8 @@ jmp .Lcopy_user_handle_tail .previous - _ASM_EXTABLE_UA(100b, 103b) - _ASM_EXTABLE_UA(101b, 103b) + _ASM_EXTABLE_CPY(100b, 103b) + _ASM_EXTABLE_CPY(101b, 103b) .endm /* @@ -116,26 +117,26 @@ SYM_FUNC_START(copy_user_generic_unrolled) 60: jmp .Lcopy_user_handle_tail /* ecx is zerorest also */ .previous - _ASM_EXTABLE_UA(1b, 30b) - _ASM_EXTABLE_UA(2b, 30b) - _ASM_EXTABLE_UA(3b, 30b) - _ASM_EXTABLE_UA(4b, 30b) - _ASM_EXTABLE_UA(5b, 30b) - _ASM_EXTABLE_UA(6b, 30b) - _ASM_EXTABLE_UA(7b, 30b) - _ASM_EXTABLE_UA(8b, 30b) - _ASM_EXTABLE_UA(9b, 30b) - _ASM_EXTABLE_UA(10b, 30b) - _ASM_EXTABLE_UA(11b, 30b) - _ASM_EXTABLE_UA(12b, 30b) - _ASM_EXTABLE_UA(13b, 30b) - _ASM_EXTABLE_UA(14b, 30b) - _ASM_EXTABLE_UA(15b, 30b) - _ASM_EXTABLE_UA(16b, 30b) - _ASM_EXTABLE_UA(18b, 40b) - _ASM_EXTABLE_UA(19b, 40b) - _ASM_EXTABLE_UA(21b, 50b) - _ASM_EXTABLE_UA(22b, 50b) + _ASM_EXTABLE_CPY(1b, 30b) + _ASM_EXTABLE_CPY(2b, 30b) + _ASM_EXTABLE_CPY(3b, 30b) + _ASM_EXTABLE_CPY(4b, 30b) + _ASM_EXTABLE_CPY(5b, 30b) + _ASM_EXTABLE_CPY(6b, 30b) + _ASM_EXTABLE_CPY(7b, 30b) + _ASM_EXTABLE_CPY(8b, 30b) + _ASM_EXTABLE_CPY(9b, 30b) + _ASM_EXTABLE_CPY(10b, 30b) + _ASM_EXTABLE_CPY(11b, 30b) + _ASM_EXTABLE_CPY(12b, 30b) + _ASM_EXTABLE_CPY(13b, 30b) + _ASM_EXTABLE_CPY(14b, 30b) + _ASM_EXTABLE_CPY(15b, 30b) + _ASM_EXTABLE_CPY(16b, 30b) + _ASM_EXTABLE_CPY(18b, 40b) + _ASM_EXTABLE_CPY(19b, 40b) + _ASM_EXTABLE_CPY(21b, 50b) + _ASM_EXTABLE_CPY(22b, 50b) SYM_FUNC_END(copy_user_generic_unrolled) EXPORT_SYMBOL(copy_user_generic_unrolled) @@ -180,8 +181,8 @@ SYM_FUNC_START(copy_user_generic_string) jmp .Lcopy_user_handle_tail .previous - _ASM_EXTABLE_UA(1b, 11b) - _ASM_EXTABLE_UA(3b, 12b) + _ASM_EXTABLE_CPY(1b, 11b) + _ASM_EXTABLE_CPY(3b, 12b) SYM_FUNC_END(copy_user_generic_string) EXPORT_SYMBOL(copy_user_generic_string) @@ -213,7 +214,7 @@ SYM_FUNC_START(copy_user_enhanced_fast_string) jmp .Lcopy_user_handle_tail .previous - _ASM_EXTABLE_UA(1b, 12b) + _ASM_EXTABLE_CPY(1b, 12b) SYM_FUNC_END(copy_user_enhanced_fast_string) EXPORT_SYMBOL(copy_user_enhanced_fast_string) @@ -221,6 +222,7 @@ EXPORT_SYMBOL(copy_user_enhanced_fast_string) * Try to copy last bytes and clear the rest if needed. * Since protection fault in copy_from/to_user is not a normal situation, * it is not necessary to optimize tail handling. + * Don't try to copy the tail if machine check happened * * Input: * rdi destination @@ -232,12 +234,25 @@ EXPORT_SYMBOL(copy_user_enhanced_fast_string) */ SYM_CODE_START_LOCAL(.Lcopy_user_handle_tail) movl %edx,%ecx + cmp $X86_TRAP_MC,%eax /* check if X86_TRAP_MC */ + je 3f 1: rep movsb 2: mov %ecx,%eax ASM_CLAC ret - _ASM_EXTABLE_UA(1b, 2b) + /* + * Return zero to pretend that this copy succeeded. This + * is counter-intuitive, but needed to prevent the code + * in lib/iov_iter.c from retrying and running back into + * the poison cache line again. The machine check handler + * will ensure that a SIGBUS is sent to the task. + */ +3: xorl %eax,%eax + ASM_CLAC + ret + + _ASM_EXTABLE_CPY(1b, 2b) SYM_CODE_END(.Lcopy_user_handle_tail) /* @@ -366,27 +381,27 @@ SYM_FUNC_START(__copy_user_nocache) jmp .Lcopy_user_handle_tail .previous - _ASM_EXTABLE_UA(1b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(2b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(3b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(4b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(5b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(6b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(7b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(8b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(9b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(10b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(11b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(12b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(13b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(14b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(15b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(16b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(20b, .L_fixup_8b_copy) - _ASM_EXTABLE_UA(21b, .L_fixup_8b_copy) - _ASM_EXTABLE_UA(30b, .L_fixup_4b_copy) - _ASM_EXTABLE_UA(31b, .L_fixup_4b_copy) - _ASM_EXTABLE_UA(40b, .L_fixup_1b_copy) - _ASM_EXTABLE_UA(41b, .L_fixup_1b_copy) + _ASM_EXTABLE_CPY(1b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(2b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(3b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(4b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(5b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(6b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(7b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(8b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(9b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(10b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(11b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(12b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(13b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(14b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(15b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(16b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(20b, .L_fixup_8b_copy) + _ASM_EXTABLE_CPY(21b, .L_fixup_8b_copy) + _ASM_EXTABLE_CPY(30b, .L_fixup_4b_copy) + _ASM_EXTABLE_CPY(31b, .L_fixup_4b_copy) + _ASM_EXTABLE_CPY(40b, .L_fixup_1b_copy) + _ASM_EXTABLE_CPY(41b, .L_fixup_1b_copy) SYM_FUNC_END(__copy_user_nocache) EXPORT_SYMBOL(__copy_user_nocache) diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S index bbcc05bcefad..037faac46b0c 100644 --- a/arch/x86/lib/memcpy_64.S +++ b/arch/x86/lib/memcpy_64.S @@ -4,7 +4,6 @@ #include <linux/linkage.h> #include <asm/errno.h> #include <asm/cpufeatures.h> -#include <asm/mcsafe_test.h> #include <asm/alternative-asm.h> #include <asm/export.h> @@ -187,117 +186,3 @@ SYM_FUNC_START_LOCAL(memcpy_orig) SYM_FUNC_END(memcpy_orig) .popsection - -#ifndef CONFIG_UML - -MCSAFE_TEST_CTL - -/* - * __memcpy_mcsafe - memory copy with machine check exception handling - * Note that we only catch machine checks when reading the source addresses. - * Writes to target are posted and don't generate machine checks. - */ -SYM_FUNC_START(__memcpy_mcsafe) - cmpl $8, %edx - /* Less than 8 bytes? Go to byte copy loop */ - jb .L_no_whole_words - - /* Check for bad alignment of source */ - testl $7, %esi - /* Already aligned */ - jz .L_8byte_aligned - - /* Copy one byte at a time until source is 8-byte aligned */ - movl %esi, %ecx - andl $7, %ecx - subl $8, %ecx - negl %ecx - subl %ecx, %edx -.L_read_leading_bytes: - movb (%rsi), %al - MCSAFE_TEST_SRC %rsi 1 .E_leading_bytes - MCSAFE_TEST_DST %rdi 1 .E_leading_bytes -.L_write_leading_bytes: - movb %al, (%rdi) - incq %rsi - incq %rdi - decl %ecx - jnz .L_read_leading_bytes - -.L_8byte_aligned: - movl %edx, %ecx - andl $7, %edx - shrl $3, %ecx - jz .L_no_whole_words - -.L_read_words: - movq (%rsi), %r8 - MCSAFE_TEST_SRC %rsi 8 .E_read_words - MCSAFE_TEST_DST %rdi 8 .E_write_words -.L_write_words: - movq %r8, (%rdi) - addq $8, %rsi - addq $8, %rdi - decl %ecx - jnz .L_read_words - - /* Any trailing bytes? */ -.L_no_whole_words: - andl %edx, %edx - jz .L_done_memcpy_trap - - /* Copy trailing bytes */ - movl %edx, %ecx -.L_read_trailing_bytes: - movb (%rsi), %al - MCSAFE_TEST_SRC %rsi 1 .E_trailing_bytes - MCSAFE_TEST_DST %rdi 1 .E_trailing_bytes -.L_write_trailing_bytes: - movb %al, (%rdi) - incq %rsi - incq %rdi - decl %ecx - jnz .L_read_trailing_bytes - - /* Copy successful. Return zero */ -.L_done_memcpy_trap: - xorl %eax, %eax -.L_done: - ret -SYM_FUNC_END(__memcpy_mcsafe) -EXPORT_SYMBOL_GPL(__memcpy_mcsafe) - - .section .fixup, "ax" - /* - * Return number of bytes not copied for any failure. Note that - * there is no "tail" handling since the source buffer is 8-byte - * aligned and poison is cacheline aligned. - */ -.E_read_words: - shll $3, %ecx -.E_leading_bytes: - addl %edx, %ecx -.E_trailing_bytes: - mov %ecx, %eax - jmp .L_done - - /* - * For write fault handling, given the destination is unaligned, - * we handle faults on multi-byte writes with a byte-by-byte - * copy up to the write-protected page. - */ -.E_write_words: - shll $3, %ecx - addl %edx, %ecx - movl %ecx, %edx - jmp mcsafe_handle_tail - - .previous - - _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes) - _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words) - _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes) - _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes) - _ASM_EXTABLE(.L_write_words, .E_write_words) - _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes) -#endif diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c index 1847e993ac63..508c81e97ab1 100644 --- a/arch/x86/lib/usercopy_64.c +++ b/arch/x86/lib/usercopy_64.c @@ -56,27 +56,6 @@ unsigned long clear_user(void __user *to, unsigned long n) } EXPORT_SYMBOL(clear_user); -/* - * Similar to copy_user_handle_tail, probe for the write fault point, - * but reuse __memcpy_mcsafe in case a new read error is encountered. - * clac() is handled in _copy_to_iter_mcsafe(). - */ -__visible notrace unsigned long -mcsafe_handle_tail(char *to, char *from, unsigned len) -{ - for (; len; --len, to++, from++) { - /* - * Call the assembly routine back directly since - * memcpy_mcsafe() may silently fallback to memcpy. - */ - unsigned long rem = __memcpy_mcsafe(to, from, 1); - - if (rem) - break; - } - return len; -} - #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE /** * clean_cache_range - write back a cache range with CLWB diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index 1d6cb07f4f86..5829457f7ca3 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -80,6 +80,18 @@ __visible bool ex_handler_uaccess(const struct exception_table_entry *fixup, } EXPORT_SYMBOL(ex_handler_uaccess); +__visible bool ex_handler_copy(const struct exception_table_entry *fixup, + struct pt_regs *regs, int trapnr, + unsigned long error_code, + unsigned long fault_addr) +{ + WARN_ONCE(trapnr == X86_TRAP_GP, "General protection fault in user access. Non-canonical address?"); + regs->ip = ex_fixup_addr(fixup); + regs->ax = trapnr; + return true; +} +EXPORT_SYMBOL(ex_handler_copy); + __visible bool ex_handler_rdmsr_unsafe(const struct exception_table_entry *fixup, struct pt_regs *regs, int trapnr, unsigned long error_code, @@ -125,17 +137,21 @@ __visible bool ex_handler_clear_fs(const struct exception_table_entry *fixup, } EXPORT_SYMBOL(ex_handler_clear_fs); -__visible bool ex_has_fault_handler(unsigned long ip) +enum handler_type ex_get_fault_handler_type(unsigned long ip) { const struct exception_table_entry *e; ex_handler_t handler; e = search_exception_tables(ip); if (!e) - return false; + return EX_HANDLER_NONE; handler = ex_fixup_handler(e); - - return handler == ex_handler_fault; + if (handler == ex_handler_fault) + return EX_HANDLER_FAULT; + else if (handler == ex_handler_uaccess || handler == ex_handler_copy) + return EX_HANDLER_UACCESS; + else + return EX_HANDLER_OTHER; } int fixup_exception(struct pt_regs *regs, int trapnr, unsigned long error_code, diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 6e3e8a124903..42606a04ae85 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1128,7 +1128,7 @@ access_error(unsigned long error_code, struct vm_area_struct *vma) return 0; } -static int fault_in_kernel_space(unsigned long address) +bool fault_in_kernel_space(unsigned long address) { /* * On 64-bit systems, the vsyscall page is at an address above |