diff options
Diffstat (limited to 'mm/kmsan/hooks.c')
| -rw-r--r-- | mm/kmsan/hooks.c | 86 |
1 files changed, 51 insertions, 35 deletions
diff --git a/mm/kmsan/hooks.c b/mm/kmsan/hooks.c index 5d6e2dee5692..3df45c25c1f6 100644 --- a/mm/kmsan/hooks.c +++ b/mm/kmsan/hooks.c @@ -39,12 +39,10 @@ void kmsan_task_create(struct task_struct *task) void kmsan_task_exit(struct task_struct *task) { - struct kmsan_ctx *ctx = &task->kmsan_ctx; - if (!kmsan_enabled || kmsan_in_runtime()) return; - ctx->allow_reporting = false; + kmsan_disable_current(); } void kmsan_slab_alloc(struct kmem_cache *s, void *object, gfp_t flags) @@ -76,7 +74,7 @@ void kmsan_slab_free(struct kmem_cache *s, void *object) return; /* RCU slabs could be legally used after free within the RCU period */ - if (unlikely(s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))) + if (unlikely(s->flags & SLAB_TYPESAFE_BY_RCU)) return; /* * If there's a constructor, freed memory must remain in the same state @@ -267,7 +265,8 @@ void kmsan_copy_to_user(void __user *to, const void *from, size_t to_copy, return; ua_flags = user_access_save(); - if ((u64)to < TASK_SIZE) { + if (!IS_ENABLED(CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE) || + (u64)to < TASK_SIZE) { /* This is a user memory access, check it. */ kmsan_internal_check_memory((void *)from, to_copy - left, to, REASON_COPY_TO_USER); @@ -285,6 +284,17 @@ void kmsan_copy_to_user(void __user *to, const void *from, size_t to_copy, } EXPORT_SYMBOL(kmsan_copy_to_user); +void kmsan_memmove(void *to, const void *from, size_t size) +{ + if (!kmsan_enabled || kmsan_in_runtime()) + return; + + kmsan_enter_runtime(); + kmsan_internal_memmove_metadata(to, (void *)from, size); + kmsan_leave_runtime(); +} +EXPORT_SYMBOL(kmsan_memmove); + /* Helper function to check an URB. */ void kmsan_handle_urb(const struct urb *urb, bool is_out) { @@ -293,7 +303,8 @@ void kmsan_handle_urb(const struct urb *urb, bool is_out) if (is_out) kmsan_internal_check_memory(urb->transfer_buffer, urb->transfer_buffer_length, - /*user_addr*/ 0, REASON_SUBMIT_URB); + /*user_addr*/ NULL, + REASON_SUBMIT_URB); else kmsan_internal_unpoison_memory(urb->transfer_buffer, urb->transfer_buffer_length, @@ -306,14 +317,14 @@ static void kmsan_handle_dma_page(const void *addr, size_t size, { switch (dir) { case DMA_BIDIRECTIONAL: - kmsan_internal_check_memory((void *)addr, size, /*user_addr*/ 0, - REASON_ANY); + kmsan_internal_check_memory((void *)addr, size, + /*user_addr*/ NULL, REASON_ANY); kmsan_internal_unpoison_memory((void *)addr, size, /*checked*/ false); break; case DMA_TO_DEVICE: - kmsan_internal_check_memory((void *)addr, size, /*user_addr*/ 0, - REASON_ANY); + kmsan_internal_check_memory((void *)addr, size, + /*user_addr*/ NULL, REASON_ANY); break; case DMA_FROM_DEVICE: kmsan_internal_unpoison_memory((void *)addr, size, @@ -346,6 +357,7 @@ void kmsan_handle_dma(struct page *page, size_t offset, size_t size, size -= to_go; } } +EXPORT_SYMBOL_GPL(kmsan_handle_dma); void kmsan_handle_dma_sg(struct scatterlist *sg, int nents, enum dma_data_direction dir) @@ -359,6 +371,12 @@ void kmsan_handle_dma_sg(struct scatterlist *sg, int nents, } /* Functions from kmsan-checks.h follow. */ + +/* + * To create an origin, kmsan_poison_memory() unwinds the stacks and stores it + * into the stack depot. This may cause deadlocks if done from within KMSAN + * runtime, therefore we bail out if kmsan_in_runtime(). + */ void kmsan_poison_memory(const void *address, size_t size, gfp_t flags) { if (!kmsan_enabled || kmsan_in_runtime()) @@ -371,54 +389,52 @@ void kmsan_poison_memory(const void *address, size_t size, gfp_t flags) } EXPORT_SYMBOL(kmsan_poison_memory); +/* + * Unlike kmsan_poison_memory(), this function can be used from within KMSAN + * runtime, because it does not trigger allocations or call instrumented code. + */ void kmsan_unpoison_memory(const void *address, size_t size) { unsigned long ua_flags; - if (!kmsan_enabled || kmsan_in_runtime()) + if (!kmsan_enabled) return; ua_flags = user_access_save(); - kmsan_enter_runtime(); /* The users may want to poison/unpoison random memory. */ kmsan_internal_unpoison_memory((void *)address, size, KMSAN_POISON_NOCHECK); - kmsan_leave_runtime(); user_access_restore(ua_flags); } EXPORT_SYMBOL(kmsan_unpoison_memory); /* - * Version of kmsan_unpoison_memory() that can be called from within the KMSAN - * runtime. - * - * Non-instrumented IRQ entry functions receive struct pt_regs from assembly - * code. Those regs need to be unpoisoned, otherwise using them will result in - * false positives. - * Using kmsan_unpoison_memory() is not an option in entry code, because the - * return value of in_task() is inconsistent - as a result, certain calls to - * kmsan_unpoison_memory() are ignored. kmsan_unpoison_entry_regs() ensures that - * the registers are unpoisoned even if kmsan_in_runtime() is true in the early - * entry code. + * Version of kmsan_unpoison_memory() called from IRQ entry functions. */ void kmsan_unpoison_entry_regs(const struct pt_regs *regs) { - unsigned long ua_flags; - - if (!kmsan_enabled) - return; - - ua_flags = user_access_save(); - kmsan_internal_unpoison_memory((void *)regs, sizeof(*regs), - KMSAN_POISON_NOCHECK); - user_access_restore(ua_flags); + kmsan_unpoison_memory((void *)regs, sizeof(*regs)); } void kmsan_check_memory(const void *addr, size_t size) { if (!kmsan_enabled) return; - return kmsan_internal_check_memory((void *)addr, size, /*user_addr*/ 0, - REASON_ANY); + return kmsan_internal_check_memory((void *)addr, size, + /*user_addr*/ NULL, REASON_ANY); } EXPORT_SYMBOL(kmsan_check_memory); + +void kmsan_enable_current(void) +{ + KMSAN_WARN_ON(current->kmsan_ctx.depth == 0); + current->kmsan_ctx.depth--; +} +EXPORT_SYMBOL(kmsan_enable_current); + +void kmsan_disable_current(void) +{ + current->kmsan_ctx.depth++; + KMSAN_WARN_ON(current->kmsan_ctx.depth == 0); +} +EXPORT_SYMBOL(kmsan_disable_current); |