diff options
-rw-r--r-- | arch/x86/Kconfig | 2 | ||||
-rw-r--r-- | arch/x86/include/asm/refcount.h | 2 | ||||
-rw-r--r-- | arch/x86/include/asm/rwsem.h | 53 | ||||
-rw-r--r-- | arch/x86/mm/extable.c | 7 | ||||
-rw-r--r-- | include/asm-generic/vmlinux.lds.h | 1 |
5 files changed, 36 insertions, 29 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 971feac13506..90535646b83d 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -55,7 +55,7 @@ config X86 select ARCH_HAS_KCOV if X86_64 select ARCH_HAS_PMEM_API if X86_64 # Causing hangs/crashes, see the commit that added this change for details. - select ARCH_HAS_REFCOUNT if BROKEN + select ARCH_HAS_REFCOUNT select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 select ARCH_HAS_SET_MEMORY select ARCH_HAS_SG_CHAIN diff --git a/arch/x86/include/asm/refcount.h b/arch/x86/include/asm/refcount.h index ff871210b9f2..4e44250e7d0d 100644 --- a/arch/x86/include/asm/refcount.h +++ b/arch/x86/include/asm/refcount.h @@ -15,7 +15,7 @@ * back to the regular execution flow in .text. */ #define _REFCOUNT_EXCEPTION \ - ".pushsection .text.unlikely\n" \ + ".pushsection .text..refcount\n" \ "111:\tlea %[counter], %%" _ASM_CX "\n" \ "112:\t" ASM_UD0 "\n" \ ASM_UNREACHABLE \ diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h index 7116b7931c7b..a8f486e7a124 100644 --- a/arch/x86/include/asm/rwsem.h +++ b/arch/x86/include/asm/rwsem.h @@ -63,14 +63,14 @@ static inline void __down_read(struct rw_semaphore *sem) { asm volatile("# beginning down_read\n\t" - LOCK_PREFIX _ASM_INC "(%1)\n\t" + LOCK_PREFIX _ASM_INC "(%[sem])\n\t" /* adds 0x00000001 */ " jns 1f\n" " call call_rwsem_down_read_failed\n" "1:\n\t" "# ending down_read\n\t" : "+m" (sem->count) - : "a" (sem) + : [sem] "a" (sem) : "memory", "cc"); } @@ -81,17 +81,18 @@ static inline bool __down_read_trylock(struct rw_semaphore *sem) { long result, tmp; asm volatile("# beginning __down_read_trylock\n\t" - " mov %0,%1\n\t" + " mov %[count],%[result]\n\t" "1:\n\t" - " mov %1,%2\n\t" - " add %3,%2\n\t" + " mov %[result],%[tmp]\n\t" + " add %[inc],%[tmp]\n\t" " jle 2f\n\t" - LOCK_PREFIX " cmpxchg %2,%0\n\t" + LOCK_PREFIX " cmpxchg %[tmp],%[count]\n\t" " jnz 1b\n\t" "2:\n\t" "# ending __down_read_trylock\n\t" - : "+m" (sem->count), "=&a" (result), "=&r" (tmp) - : "i" (RWSEM_ACTIVE_READ_BIAS) + : [count] "+m" (sem->count), [result] "=&a" (result), + [tmp] "=&r" (tmp) + : [inc] "i" (RWSEM_ACTIVE_READ_BIAS) : "memory", "cc"); return result >= 0; } @@ -105,7 +106,7 @@ static inline bool __down_read_trylock(struct rw_semaphore *sem) struct rw_semaphore* ret; \ \ asm volatile("# beginning down_write\n\t" \ - LOCK_PREFIX " xadd %1,(%4)\n\t" \ + LOCK_PREFIX " xadd %[tmp],(%[sem])\n\t" \ /* adds 0xffff0001, returns the old value */ \ " test " __ASM_SEL(%w1,%k1) "," __ASM_SEL(%w1,%k1) "\n\t" \ /* was the active mask 0 before? */\ @@ -113,9 +114,9 @@ static inline bool __down_read_trylock(struct rw_semaphore *sem) " call " slow_path "\n" \ "1:\n" \ "# ending down_write" \ - : "+m" (sem->count), "=d" (tmp), \ + : "+m" (sem->count), [tmp] "=d" (tmp), \ "=a" (ret), ASM_CALL_CONSTRAINT \ - : "a" (sem), "1" (RWSEM_ACTIVE_WRITE_BIAS) \ + : [sem] "a" (sem), "[tmp]" (RWSEM_ACTIVE_WRITE_BIAS) \ : "memory", "cc"); \ ret; \ }) @@ -141,21 +142,21 @@ static inline bool __down_write_trylock(struct rw_semaphore *sem) bool result; long tmp0, tmp1; asm volatile("# beginning __down_write_trylock\n\t" - " mov %0,%1\n\t" + " mov %[count],%[tmp0]\n\t" "1:\n\t" " test " __ASM_SEL(%w1,%k1) "," __ASM_SEL(%w1,%k1) "\n\t" /* was the active mask 0 before? */ " jnz 2f\n\t" - " mov %1,%2\n\t" - " add %4,%2\n\t" - LOCK_PREFIX " cmpxchg %2,%0\n\t" + " mov %[tmp0],%[tmp1]\n\t" + " add %[inc],%[tmp1]\n\t" + LOCK_PREFIX " cmpxchg %[tmp1],%[count]\n\t" " jnz 1b\n\t" "2:\n\t" CC_SET(e) "# ending __down_write_trylock\n\t" - : "+m" (sem->count), "=&a" (tmp0), "=&r" (tmp1), - CC_OUT(e) (result) - : "er" (RWSEM_ACTIVE_WRITE_BIAS) + : [count] "+m" (sem->count), [tmp0] "=&a" (tmp0), + [tmp1] "=&r" (tmp1), CC_OUT(e) (result) + : [inc] "er" (RWSEM_ACTIVE_WRITE_BIAS) : "memory"); return result; } @@ -167,14 +168,14 @@ static inline void __up_read(struct rw_semaphore *sem) { long tmp; asm volatile("# beginning __up_read\n\t" - LOCK_PREFIX " xadd %1,(%2)\n\t" + LOCK_PREFIX " xadd %[tmp],(%[sem])\n\t" /* subtracts 1, returns the old value */ " jns 1f\n\t" " call call_rwsem_wake\n" /* expects old value in %edx */ "1:\n" "# ending __up_read\n" - : "+m" (sem->count), "=d" (tmp) - : "a" (sem), "1" (-RWSEM_ACTIVE_READ_BIAS) + : "+m" (sem->count), [tmp] "=d" (tmp) + : [sem] "a" (sem), "[tmp]" (-RWSEM_ACTIVE_READ_BIAS) : "memory", "cc"); } @@ -185,14 +186,14 @@ static inline void __up_write(struct rw_semaphore *sem) { long tmp; asm volatile("# beginning __up_write\n\t" - LOCK_PREFIX " xadd %1,(%2)\n\t" + LOCK_PREFIX " xadd %[tmp],(%[sem])\n\t" /* subtracts 0xffff0001, returns the old value */ " jns 1f\n\t" " call call_rwsem_wake\n" /* expects old value in %edx */ "1:\n\t" "# ending __up_write\n" - : "+m" (sem->count), "=d" (tmp) - : "a" (sem), "1" (-RWSEM_ACTIVE_WRITE_BIAS) + : "+m" (sem->count), [tmp] "=d" (tmp) + : [sem] "a" (sem), "[tmp]" (-RWSEM_ACTIVE_WRITE_BIAS) : "memory", "cc"); } @@ -202,7 +203,7 @@ static inline void __up_write(struct rw_semaphore *sem) static inline void __downgrade_write(struct rw_semaphore *sem) { asm volatile("# beginning __downgrade_write\n\t" - LOCK_PREFIX _ASM_ADD "%2,(%1)\n\t" + LOCK_PREFIX _ASM_ADD "%[inc],(%[sem])\n\t" /* * transitions 0xZZZZ0001 -> 0xYYYY0001 (i386) * 0xZZZZZZZZ00000001 -> 0xYYYYYYYY00000001 (x86_64) @@ -212,7 +213,7 @@ static inline void __downgrade_write(struct rw_semaphore *sem) "1:\n\t" "# ending __downgrade_write\n" : "+m" (sem->count) - : "a" (sem), "er" (-RWSEM_WAITING_BIAS) + : [sem] "a" (sem), [inc] "er" (-RWSEM_WAITING_BIAS) : "memory", "cc"); } diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index c3521e2be396..3321b446b66c 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -67,12 +67,17 @@ bool ex_handler_refcount(const struct exception_table_entry *fixup, * 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; diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 8acfc1e099e1..e549bff87c5b 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -459,6 +459,7 @@ #define TEXT_TEXT \ ALIGN_FUNCTION(); \ *(.text.hot TEXT_MAIN .text.fixup .text.unlikely) \ + *(.text..refcount) \ *(.ref.text) \ MEM_KEEP(init.text) \ MEM_KEEP(exit.text) \ |