diff options
| -rw-r--r-- | arch/powerpc/perf/callchain.h | 25 | ||||
| -rw-r--r-- | arch/powerpc/perf/callchain_32.c | 21 | ||||
| -rw-r--r-- | arch/powerpc/perf/callchain_64.c | 13 |
3 files changed, 29 insertions, 30 deletions
diff --git a/arch/powerpc/perf/callchain.h b/arch/powerpc/perf/callchain.h index 7a2cb9e1181a..ae24d4a00da6 100644 --- a/arch/powerpc/perf/callchain.h +++ b/arch/powerpc/perf/callchain.h @@ -2,7 +2,7 @@ #ifndef _POWERPC_PERF_CALLCHAIN_H #define _POWERPC_PERF_CALLCHAIN_H -int read_user_stack_slow(void __user *ptr, void *buf, int nb); +int read_user_stack_slow(const void __user *ptr, void *buf, int nb); void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs); void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry, @@ -16,4 +16,27 @@ static inline bool invalid_user_sp(unsigned long sp) return (!sp || (sp & mask) || (sp > top)); } +/* + * On 32-bit we just access the address and let hash_page create a + * HPTE if necessary, so there is no need to fall back to reading + * the page tables. Since this is called at interrupt level, + * do_page_fault() won't treat a DSI as a page fault. + */ +static inline int __read_user_stack(const void __user *ptr, void *ret, + size_t size) +{ + unsigned long addr = (unsigned long)ptr; + int rc; + + if (addr > TASK_SIZE - size || (addr & (size - 1))) + return -EFAULT; + + rc = copy_from_user_nofault(ret, ptr, size); + + if (IS_ENABLED(CONFIG_PPC64) && rc) + return read_user_stack_slow(ptr, ret, size); + + return rc; +} + #endif /* _POWERPC_PERF_CALLCHAIN_H */ diff --git a/arch/powerpc/perf/callchain_32.c b/arch/powerpc/perf/callchain_32.c index 542e68b8eae0..64e4013d8060 100644 --- a/arch/powerpc/perf/callchain_32.c +++ b/arch/powerpc/perf/callchain_32.c @@ -30,26 +30,9 @@ #endif /* CONFIG_PPC64 */ -/* - * On 32-bit we just access the address and let hash_page create a - * HPTE if necessary, so there is no need to fall back to reading - * the page tables. Since this is called at interrupt level, - * do_page_fault() won't treat a DSI as a page fault. - */ -static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret) +static int read_user_stack_32(const unsigned int __user *ptr, unsigned int *ret) { - int rc; - - if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) || - ((unsigned long)ptr & 3)) - return -EFAULT; - - rc = copy_from_user_nofault(ret, ptr, sizeof(*ret)); - - if (IS_ENABLED(CONFIG_PPC64) && rc) - return read_user_stack_slow(ptr, ret, 4); - - return rc; + return __read_user_stack(ptr, ret, sizeof(*ret)); } /* diff --git a/arch/powerpc/perf/callchain_64.c b/arch/powerpc/perf/callchain_64.c index fa2a1b83b9b0..fed90e827f3a 100644 --- a/arch/powerpc/perf/callchain_64.c +++ b/arch/powerpc/perf/callchain_64.c @@ -23,7 +23,7 @@ * interrupt context, so if the access faults, we read the page tables * to find which page (if any) is mapped and access it directly. */ -int read_user_stack_slow(void __user *ptr, void *buf, int nb) +int read_user_stack_slow(const void __user *ptr, void *buf, int nb) { unsigned long addr = (unsigned long) ptr; @@ -44,16 +44,9 @@ int read_user_stack_slow(void __user *ptr, void *buf, int nb) return -EFAULT; } -static int read_user_stack_64(unsigned long __user *ptr, unsigned long *ret) +static int read_user_stack_64(const unsigned long __user *ptr, unsigned long *ret) { - if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned long) || - ((unsigned long)ptr & 7)) - return -EFAULT; - - if (!copy_from_user_nofault(ret, ptr, sizeof(*ret))) - return 0; - - return read_user_stack_slow(ptr, ret, 8); + return __read_user_stack(ptr, ret, sizeof(*ret)); } /* |