diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/Kconfig | 21 | ||||
| -rw-r--r-- | arch/alpha/kernel/srmcons.c | 2 | ||||
| -rw-r--r-- | arch/arm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm64/Kconfig | 1 | ||||
| -rw-r--r-- | arch/riscv/Makefile | 1 | ||||
| -rw-r--r-- | arch/s390/configs/debug_defconfig | 1 | ||||
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/asm.h | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/refcount.h | 126 | ||||
| -rw-r--r-- | arch/x86/include/asm/uaccess.h | 154 | ||||
| -rw-r--r-- | arch/x86/include/asm/uaccess_32.h | 27 | ||||
| -rw-r--r-- | arch/x86/include/asm/uaccess_64.h | 108 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mce/core.c | 34 | ||||
| -rw-r--r-- | arch/x86/mm/extable.c | 49 |
14 files changed, 163 insertions, 369 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index a8df66e64544..2219a07dca1e 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -915,27 +915,6 @@ config STRICT_MODULE_RWX config ARCH_HAS_PHYS_TO_DMA bool -config ARCH_HAS_REFCOUNT - bool - help - An architecture selects this when it has implemented refcount_t - using open coded assembly primitives that provide an optimized - refcount_t implementation, possibly at the expense of some full - refcount state checks of CONFIG_REFCOUNT_FULL=y. - - The refcount overflow check behavior, however, must be retained. - Catching overflows is the primary security concern for protecting - against bugs in reference counts. - -config REFCOUNT_FULL - bool "Perform full reference count validation at the expense of speed" - help - Enabling this switches the refcounting infrastructure from a fast - unchecked atomic_t implementation to a fully state checked - implementation, which can be (slightly) slower but provides protections - against various use-after-free conditions that can be used in - security flaw exploits. - config HAVE_ARCH_COMPILER_H bool help diff --git a/arch/alpha/kernel/srmcons.c b/arch/alpha/kernel/srmcons.c index 438b10c44d73..2b7a314b8452 100644 --- a/arch/alpha/kernel/srmcons.c +++ b/arch/alpha/kernel/srmcons.c @@ -59,7 +59,7 @@ srmcons_do_receive_chars(struct tty_port *port) } while((result.bits.status & 1) && (++loops < 10)); if (count) - tty_schedule_flip(port); + tty_flip_buffer_push(port); return count; } diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index a1622b9290fd..a4364cce85f8 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -119,7 +119,6 @@ config ARM select OLD_SIGSUSPEND3 select PCI_SYSCALL if PCI select PERF_USE_VMALLOC - select REFCOUNT_FULL select RTC_LIB select SYS_SUPPORTS_APM_EMULATION # Above selects are sorted alphabetically; please add new ones diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index a1a828ca188c..6b73143f0cf8 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -181,7 +181,6 @@ config ARM64 select PCI_SYSCALL if PCI select POWER_RESET select POWER_SUPPLY - select REFCOUNT_FULL select SPARSE_IRQ select SWIOTLB select SYSCTL_EXCEPTION_TRACE diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 7b579a003e30..d1a961539101 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -74,6 +74,7 @@ ifeq ($(CONFIG_PERF_EVENTS),y) endif KBUILD_CFLAGS_MODULE += $(call cc-option,-mno-relax) +KBUILD_AFLAGS_MODULE += $(call as-option,-Wa$(comma)-mno-relax) # GCC versions that support the "-mstrict-align" option default to allowing # unaligned accesses. While unaligned accesses are explicitly allowed in the diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig index 38d64030aacf..2e60c80395ab 100644 --- a/arch/s390/configs/debug_defconfig +++ b/arch/s390/configs/debug_defconfig @@ -62,7 +62,6 @@ CONFIG_OPROFILE=m CONFIG_KPROBES=y CONFIG_JUMP_LABEL=y CONFIG_STATIC_KEYS_SELFTEST=y -CONFIG_REFCOUNT_FULL=y CONFIG_LOCK_EVENT_COUNTS=y CONFIG_MODULES=y CONFIG_MODULE_FORCE_LOAD=y diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index c6c71592f6e4..6002252692af 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -73,7 +73,6 @@ config X86 select ARCH_HAS_PMEM_API if X86_64 select ARCH_HAS_PTE_DEVMAP if X86_64 select ARCH_HAS_PTE_SPECIAL - select ARCH_HAS_REFCOUNT select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE select ARCH_HAS_SET_MEMORY diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h index 1b563f9167ea..cd339b88d5d4 100644 --- a/arch/x86/include/asm/asm.h +++ b/arch/x86/include/asm/asm.h @@ -141,9 +141,6 @@ # define _ASM_EXTABLE_EX(from, to) \ _ASM_EXTABLE_HANDLE(from, to, ex_handler_ext) -# define _ASM_EXTABLE_REFCOUNT(from, to) \ - _ASM_EXTABLE_HANDLE(from, to, ex_handler_refcount) - # define _ASM_NOKPROBE(entry) \ .pushsection "_kprobe_blacklist","aw" ; \ _ASM_ALIGN ; \ @@ -172,9 +169,6 @@ # define _ASM_EXTABLE_EX(from, to) \ _ASM_EXTABLE_HANDLE(from, to, ex_handler_ext) -# define _ASM_EXTABLE_REFCOUNT(from, to) \ - _ASM_EXTABLE_HANDLE(from, to, ex_handler_refcount) - /* For C file, we already have NOKPROBE_SYMBOL macro */ #endif diff --git a/arch/x86/include/asm/refcount.h b/arch/x86/include/asm/refcount.h deleted file mode 100644 index 232f856e0db0..000000000000 --- a/arch/x86/include/asm/refcount.h +++ /dev/null @@ -1,126 +0,0 @@ -#ifndef __ASM_X86_REFCOUNT_H -#define __ASM_X86_REFCOUNT_H -/* - * x86-specific implementation of refcount_t. Based on PAX_REFCOUNT from - * PaX/grsecurity. - */ -#include <linux/refcount.h> -#include <asm/bug.h> - -/* - * This is the first portion of the refcount error handling, which lives in - * .text.unlikely, and is jumped to from the CPU flag check (in the - * following macros). This saves the refcount value location into CX for - * the exception handler to use (in mm/extable.c), and then triggers the - * central refcount exception. The fixup address for the exception points - * back to the regular execution flow in .text. - */ -#define _REFCOUNT_EXCEPTION \ - ".pushsection .text..refcount\n" \ - "111:\tlea %[var], %%" _ASM_CX "\n" \ - "112:\t" ASM_UD2 "\n" \ - ASM_UNREACHABLE \ - ".popsection\n" \ - "113:\n" \ - _ASM_EXTABLE_REFCOUNT(112b, 113b) - -/* Trigger refcount exception if refcount result is negative. */ -#define REFCOUNT_CHECK_LT_ZERO \ - "js 111f\n\t" \ - _REFCOUNT_EXCEPTION - -/* Trigger refcount exception if refcount result is zero or negative. */ -#define REFCOUNT_CHECK_LE_ZERO \ - "jz 111f\n\t" \ - REFCOUNT_CHECK_LT_ZERO - -/* Trigger refcount exception unconditionally. */ -#define REFCOUNT_ERROR \ - "jmp 111f\n\t" \ - _REFCOUNT_EXCEPTION - -static __always_inline void refcount_add(unsigned int i, refcount_t *r) -{ - asm volatile(LOCK_PREFIX "addl %1,%0\n\t" - REFCOUNT_CHECK_LT_ZERO - : [var] "+m" (r->refs.counter) - : "ir" (i) - : "cc", "cx"); -} - -static __always_inline void refcount_inc(refcount_t *r) -{ - asm volatile(LOCK_PREFIX "incl %0\n\t" - REFCOUNT_CHECK_LT_ZERO - : [var] "+m" (r->refs.counter) - : : "cc", "cx"); -} - -static __always_inline void refcount_dec(refcount_t *r) -{ - asm volatile(LOCK_PREFIX "decl %0\n\t" - REFCOUNT_CHECK_LE_ZERO - : [var] "+m" (r->refs.counter) - : : "cc", "cx"); -} - -static __always_inline __must_check -bool refcount_sub_and_test(unsigned int i, refcount_t *r) -{ - bool ret = GEN_BINARY_SUFFIXED_RMWcc(LOCK_PREFIX "subl", - REFCOUNT_CHECK_LT_ZERO, - r->refs.counter, e, "er", i, "cx"); - - if (ret) { - smp_acquire__after_ctrl_dep(); - return true; - } - - return false; -} - -static __always_inline __must_check bool refcount_dec_and_test(refcount_t *r) -{ - bool ret = GEN_UNARY_SUFFIXED_RMWcc(LOCK_PREFIX "decl", - REFCOUNT_CHECK_LT_ZERO, - r->refs.counter, e, "cx"); - - if (ret) { - smp_acquire__after_ctrl_dep(); - return true; - } - - return false; -} - -static __always_inline __must_check -bool refcount_add_not_zero(unsigned int i, refcount_t *r) -{ - int c, result; - - c = atomic_read(&(r->refs)); - do { - if (unlikely(c == 0)) - return false; - - result = c + i; - - /* Did we try to increment from/to an undesirable state? */ - if (unlikely(c < 0 || c == INT_MAX || result < c)) { - asm volatile(REFCOUNT_ERROR - : : [var] "m" (r->refs.counter) - : "cc", "cx"); - break; - } - - } while (!atomic_try_cmpxchg(&(r->refs), &c, result)); - - return c != 0; -} - -static __always_inline __must_check bool refcount_inc_not_zero(refcount_t *r) -{ - return refcount_add_not_zero(1, r); -} - -#endif diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 61d93f062a36..d6a0e57ecc07 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -378,18 +378,6 @@ do { \ : "=r" (err), ltype(x) \ : "m" (__m(addr)), "i" (errret), "0" (err)) -#define __get_user_asm_nozero(x, addr, err, itype, rtype, ltype, errret) \ - asm volatile("\n" \ - "1: mov"itype" %2,%"rtype"1\n" \ - "2:\n" \ - ".section .fixup,\"ax\"\n" \ - "3: mov %3,%0\n" \ - " jmp 2b\n" \ - ".previous\n" \ - _ASM_EXTABLE_UA(1b, 3b) \ - : "=r" (err), ltype(x) \ - : "m" (__m(addr)), "i" (errret), "0" (err)) - /* * This doesn't do __uaccess_begin/end - the exception handling * around it must do that. @@ -453,6 +441,103 @@ __pu_label: \ __builtin_expect(__gu_err, 0); \ }) +#ifdef CONFIG_CC_HAS_ASM_GOTO_TIED_OUTPUT +#define __try_cmpxchg_user_asm(itype, ltype, _ptr, _pold, _new, label) ({ \ + bool success; \ + __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \ + __typeof__(*(_ptr)) __old = *_old; \ + __typeof__(*(_ptr)) __new = (_new); \ + asm_volatile_goto("\n" \ + "1: " LOCK_PREFIX "cmpxchg"itype" %[new], %[ptr]\n"\ + _ASM_EXTABLE_UA(1b, %l[label]) \ + : CC_OUT(z) (success), \ + [ptr] "+m" (*_ptr), \ + [old] "+a" (__old) \ + : [new] ltype (__new) \ + : "memory" \ + : label); \ + if (unlikely(!success)) \ + *_old = __old; \ + likely(success); }) + +#ifdef CONFIG_X86_32 +#define __try_cmpxchg64_user_asm(_ptr, _pold, _new, label) ({ \ + bool success; \ + __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \ + __typeof__(*(_ptr)) __old = *_old; \ + __typeof__(*(_ptr)) __new = (_new); \ + asm_volatile_goto("\n" \ + "1: " LOCK_PREFIX "cmpxchg8b %[ptr]\n" \ + _ASM_EXTABLE_UA(1b, %l[label]) \ + : CC_OUT(z) (success), \ + "+A" (__old), \ + [ptr] "+m" (*_ptr) \ + : "b" ((u32)__new), \ + "c" ((u32)((u64)__new >> 32)) \ + : "memory" \ + : label); \ + if (unlikely(!success)) \ + *_old = __old; \ + likely(success); }) +#endif // CONFIG_X86_32 +#else // !CONFIG_CC_HAS_ASM_GOTO_TIED_OUTPUT +#define __try_cmpxchg_user_asm(itype, ltype, _ptr, _pold, _new, label) ({ \ + int __err = 0; \ + bool success; \ + __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \ + __typeof__(*(_ptr)) __old = *_old; \ + __typeof__(*(_ptr)) __new = (_new); \ + asm volatile("\n" \ + "1: " LOCK_PREFIX "cmpxchg"itype" %[new], %[ptr]\n"\ + CC_SET(z) \ + "2:\n" \ + _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, \ + %[errout]) \ + : CC_OUT(z) (success), \ + [errout] "+r" (__err), \ + [ptr] "+m" (*_ptr), \ + [old] "+a" (__old) \ + : [new] ltype (__new) \ + : "memory"); \ + if (unlikely(__err)) \ + goto label; \ + if (unlikely(!success)) \ + *_old = __old; \ + likely(success); }) + +#ifdef CONFIG_X86_32 +/* + * Unlike the normal CMPXCHG, hardcode ECX for both success/fail and error. + * There are only six GPRs available and four (EAX, EBX, ECX, and EDX) are + * hardcoded by CMPXCHG8B, leaving only ESI and EDI. If the compiler uses + * both ESI and EDI for the memory operand, compilation will fail if the error + * is an input+output as there will be no register available for input. + */ +#define __try_cmpxchg64_user_asm(_ptr, _pold, _new, label) ({ \ + int __result; \ + __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \ + __typeof__(*(_ptr)) __old = *_old; \ + __typeof__(*(_ptr)) __new = (_new); \ + asm volatile("\n" \ + "1: " LOCK_PREFIX "cmpxchg8b %[ptr]\n" \ + "mov $0, %%ecx\n\t" \ + "setz %%cl\n" \ + "2:\n" \ + _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %%ecx) \ + : [result]"=c" (__result), \ + "+A" (__old), \ + [ptr] "+m" (*_ptr) \ + : "b" ((u32)__new), \ + "c" ((u32)((u64)__new >> 32)) \ + : "memory", "cc"); \ + if (unlikely(__result < 0)) \ + goto label; \ + if (unlikely(!__result)) \ + *_old = __old; \ + likely(__result); }) +#endif // CONFIG_X86_32 +#endif // CONFIG_CC_HAS_ASM_GOTO_TIED_OUTPUT + /* FIXME: this hack is definitely wrong -AK */ struct __large_struct { unsigned long buf[100]; }; #define __m(x) (*(struct __large_struct __user *)(x)) @@ -734,6 +819,51 @@ do { \ if (unlikely(__gu_err)) goto err_label; \ } while (0) +extern void __try_cmpxchg_user_wrong_size(void); + +#ifndef CONFIG_X86_32 +#define __try_cmpxchg64_user_asm(_ptr, _oldp, _nval, _label) \ + __try_cmpxchg_user_asm("q", "r", (_ptr), (_oldp), (_nval), _label) +#endif + +/* + * Force the pointer to u<size> to match the size expected by the asm helper. + * clang/LLVM compiles all cases and only discards the unused paths after + * processing errors, which breaks i386 if the pointer is an 8-byte value. + */ +#define unsafe_try_cmpxchg_user(_ptr, _oldp, _nval, _label) ({ \ + bool __ret; \ + __chk_user_ptr(_ptr); \ + switch (sizeof(*(_ptr))) { \ + case 1: __ret = __try_cmpxchg_user_asm("b", "q", \ + (__force u8 *)(_ptr), (_oldp), \ + (_nval), _label); \ + break; \ + case 2: __ret = __try_cmpxchg_user_asm("w", "r", \ + (__force u16 *)(_ptr), (_oldp), \ + (_nval), _label); \ + break; \ + case 4: __ret = __try_cmpxchg_user_asm("l", "r", \ + (__force u32 *)(_ptr), (_oldp), \ + (_nval), _label); \ + break; \ + case 8: __ret = __try_cmpxchg64_user_asm((__force u64 *)(_ptr), (_oldp),\ + (_nval), _label); \ + break; \ + default: __try_cmpxchg_user_wrong_size(); \ + } \ + __ret; }) + +/* "Returns" 0 on success, 1 on failure, -EFAULT if the access faults. */ +#define __try_cmpxchg_user(_ptr, _oldp, _nval, _label) ({ \ + int __ret = -EFAULT; \ + __uaccess_begin_nospec(); \ + __ret = !unsafe_try_cmpxchg_user(_ptr, _oldp, _nval, _label); \ +_label: \ + __uaccess_end(); \ + __ret; \ + }) + /* * We want the unsafe accessors to always be inlined and use * the error labels - thus the macro games. diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h index ba2dc1930630..388a40660c7b 100644 --- a/arch/x86/include/asm/uaccess_32.h +++ b/arch/x86/include/asm/uaccess_32.h @@ -23,33 +23,6 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n) static __always_inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) { - if (__builtin_constant_p(n)) { - unsigned long ret; - - switch (n) { - case 1: - ret = 0; - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u8 *)to, from, ret, - "b", "b", "=q", 1); - __uaccess_end(); - return ret; - case 2: - ret = 0; - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u16 *)to, from, ret, - "w", "w", "=r", 2); - __uaccess_end(); - return ret; - case 4: - ret = 0; - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u32 *)to, from, ret, - "l", "k", "=r", 4); - __uaccess_end(); - return ret; - } - } return __copy_user_ll(to, (__force const void *)from, n); } diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 5cd1caa8bc65..bc10e3dc64fe 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -65,117 +65,13 @@ copy_to_user_mcsafe(void *to, const void *from, unsigned len) static __always_inline __must_check unsigned long raw_copy_from_user(void *dst, const void __user *src, unsigned long size) { - int ret = 0; - - if (!__builtin_constant_p(size)) - return copy_user_generic(dst, (__force void *)src, size); - switch (size) { - case 1: - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u8 *)dst, (u8 __user *)src, - ret, "b", "b", "=q", 1); - __uaccess_end(); - return ret; - case 2: - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u16 *)dst, (u16 __user *)src, - ret, "w", "w", "=r", 2); - __uaccess_end(); - return ret; - case 4: - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u32 *)dst, (u32 __user *)src, - ret, "l", "k", "=r", 4); - __uaccess_end(); - return ret; - case 8: - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src, - ret, "q", "", "=r", 8); - __uaccess_end(); - return ret; - case 10: - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src, - ret, "q", "", "=r", 10); - if (likely(!ret)) - __get_user_asm_nozero(*(u16 *)(8 + (char *)dst), - (u16 __user *)(8 + (char __user *)src), - ret, "w", "w", "=r", 2); - __uaccess_end(); - return ret; - case 16: - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src, - ret, "q", "", "=r", 16); - if (likely(!ret)) - __get_user_asm_nozero(*(u64 *)(8 + (char *)dst), - (u64 __user *)(8 + (char __user *)src), - ret, "q", "", "=r", 8); - __uaccess_end(); - return ret; - default: - return copy_user_generic(dst, (__force void *)src, size); - } + return copy_user_generic(dst, (__force void *)src, size); } static __always_inline __must_check unsigned long raw_copy_to_user(void __user *dst, const void *src, unsigned long size) { - int ret = 0; - - if (!__builtin_constant_p(size)) - return copy_user_generic((__force void *)dst, src, size); - switch (size) { - case 1: - __uaccess_begin(); - __put_user_asm(*(u8 *)src, (u8 __user *)dst, - ret, "b", "b", "iq", 1); - __uaccess_end(); - return ret; - case 2: - __uaccess_begin(); - __put_user_asm(*(u16 *)src, (u16 __user *)dst, - ret, "w", "w", "ir", 2); - __uaccess_end(); - return ret; - case 4: - __uaccess_begin(); - __put_user_asm(*(u32 *)src, (u32 __user *)dst, - ret, "l", "k", "ir", 4); - __uaccess_end(); - return ret; - case 8: - __uaccess_begin(); - __put_user_asm(*(u64 *)src, (u64 __user *)dst, - ret, "q", "", "er", 8); - __uaccess_end(); - return ret; - case 10: - __uaccess_begin(); - __put_user_asm(*(u64 *)src, (u64 __user *)dst, - ret, "q", "", "er", 10); - if (likely(!ret)) { - asm("":::"memory"); - __put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst, - ret, "w", "w", "ir", 2); - } - __uaccess_end(); - return ret; - case 16: - __uaccess_begin(); - __put_user_asm(*(u64 *)src, (u64 __user *)dst, - ret, "q", "", "er", 16); - if (likely(!ret)) { - asm("":::"memory"); - __put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst, - ret, "q", "", "er", 8); - } - __uaccess_end(); - return ret; - default: - return copy_user_generic((__force void *)dst, src, size); - } + return copy_user_generic((__force void *)dst, src, size); } static __always_inline __must_check diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 8a2b8e791314..9b98a7d8ac60 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -397,13 +397,16 @@ 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) +static void ex_handler_msr_mce(struct pt_regs *regs, bool wrmsr) { - pr_emerg("MSR access error: RDMSR from 0x%x at rIP: 0x%lx (%pS)\n", - (unsigned int)regs->cx, regs->ip, (void *)regs->ip); + if (wrmsr) { + 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); + } else { + 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); @@ -411,7 +414,14 @@ __visible bool ex_handler_rdmsr_fault(const struct exception_table_entry *fixup, while (true) cpu_relax(); +} +__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) +{ + ex_handler_msr_mce(regs, false); return true; } @@ -447,17 +457,7 @@ __visible bool ex_handler_wrmsr_fault(const struct exception_table_entry *fixup, 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(); - + ex_handler_msr_mce(regs, true); return true; } diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index 4d75bc656f97..30bb0bd3b1b8 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -45,55 +45,6 @@ __visible bool ex_handler_fault(const struct exception_table_entry *fixup, EXPORT_SYMBOL_GPL(ex_handler_fault); /* - * Handler for UD0 exception following a failed test against the - * result of a refcount inc/dec/add/sub. - */ -__visible bool ex_handler_refcount(const struct exception_table_entry *fixup, - struct pt_regs *regs, int trapnr, - unsigned long error_code, - unsigned long fault_addr) -{ - /* First unconditionally saturate the refcount. */ - *(int *)regs->cx = INT_MIN / 2; - - /* - * Strictly speaking, this reports the fixup destination, not - * the fault location, and not the actually overflowing - * instruction, which is the instruction before the "js", but - * since that instruction could be a variety of lengths, just - * report the location after the overflow, which should be close - * enough for finding the overflow, as it's at least back in - * the function, having returned from .text.unlikely. - */ - regs->ip = ex_fixup_addr(fixup); - - /* - * This function has been called because either a negative refcount - * value was seen by any of the refcount functions, or a zero - * refcount value was seen by refcount_dec(). - * - * If we crossed from INT_MAX to INT_MIN, OF (Overflow Flag: result - * wrapped around) will be set. Additionally, seeing the refcount - * reach 0 will set ZF (Zero Flag: result was zero). In each of - * these cases we want a report, since it's a boundary condition. - * The SF case is not reported since it indicates post-boundary - * manipulations below zero or above INT_MAX. And if none of the - * flags are set, something has gone very wrong, so report it. - */ - if (regs->flags & (X86_EFLAGS_OF | X86_EFLAGS_ZF)) { - bool zero = regs->flags & X86_EFLAGS_ZF; - - refcount_error_report(regs, zero ? "hit zero" : "overflow"); - } else if ((regs->flags & X86_EFLAGS_SF) == 0) { - /* Report if none of OF, ZF, nor SF are set. */ - refcount_error_report(regs, "unexpected saturation"); - } - - return true; -} -EXPORT_SYMBOL(ex_handler_refcount); - -/* * Handler for when we fail to restore a task's FPU state. We should never get * here because the FPU state of a task using the FPU (task->thread.fpu.state) * should always be valid. However, past bugs have allowed userspace to set |