diff options
| -rw-r--r-- | arch/x86/kernel/ftrace.c | 9 | ||||
| -rw-r--r-- | include/linux/ftrace.h | 8 | ||||
| -rw-r--r-- | kernel/extable.c | 7 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 38 |
4 files changed, 59 insertions, 3 deletions
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 1aea94d336c7..60881d919432 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -712,7 +712,8 @@ union ftrace_op_code_union { } __attribute__((packed)); }; -static unsigned long create_trampoline(struct ftrace_ops *ops) +static unsigned long +create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) { unsigned const char *jmp; unsigned long start_offset; @@ -749,6 +750,8 @@ static unsigned long create_trampoline(struct ftrace_ops *ops) if (!trampoline) return 0; + *tramp_size = size + MCOUNT_INSN_SIZE + sizeof(void *); + /* Copy ftrace_caller onto the trampoline memory */ ret = probe_kernel_read(trampoline, (void *)start_offset, size); if (WARN_ON(ret < 0)) { @@ -819,6 +822,7 @@ void arch_ftrace_update_trampoline(struct ftrace_ops *ops) unsigned char *new; unsigned long offset; unsigned long ip; + unsigned int size; int ret; if (ops->trampoline) { @@ -829,9 +833,10 @@ void arch_ftrace_update_trampoline(struct ftrace_ops *ops) if (!(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) return; } else { - ops->trampoline = create_trampoline(ops); + ops->trampoline = create_trampoline(ops, &size); if (!ops->trampoline) return; + ops->trampoline_size = size; } offset = calc_trampoline_call_offset(ops->flags & FTRACE_OPS_FL_SAVE_REGS); diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 619e37cc17fd..7b2616fa2472 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -150,6 +150,7 @@ struct ftrace_ops { struct ftrace_ops_hash *func_hash; struct ftrace_ops_hash old_hash; unsigned long trampoline; + unsigned long trampoline_size; #endif }; @@ -297,6 +298,8 @@ extern int ftrace_text_reserved(const void *start, const void *end); extern int ftrace_nr_registered_ops(void); +bool is_ftrace_trampoline(unsigned long addr); + /* * The dyn_ftrace record's flags field is split into two parts. * the first part which is '0-FTRACE_REF_MAX' is a counter of @@ -596,6 +599,11 @@ static inline ssize_t ftrace_notrace_write(struct file *file, const char __user size_t cnt, loff_t *ppos) { return -ENODEV; } static inline int ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } + +static inline bool is_ftrace_trampoline(unsigned long addr) +{ + return false; +} #endif /* CONFIG_DYNAMIC_FTRACE */ /* totally disable ftrace - can not re-enable after this */ diff --git a/kernel/extable.c b/kernel/extable.c index d8a6446adbcb..c98f926277a8 100644 --- a/kernel/extable.c +++ b/kernel/extable.c @@ -18,6 +18,7 @@ #include <linux/ftrace.h> #include <linux/memory.h> #include <linux/module.h> +#include <linux/ftrace.h> #include <linux/mutex.h> #include <linux/init.h> @@ -102,6 +103,8 @@ int __kernel_text_address(unsigned long addr) return 1; if (is_module_text_address(addr)) return 1; + if (is_ftrace_trampoline(addr)) + return 1; /* * There might be init symbols in saved stacktraces. * Give those symbols a chance to be printed in @@ -119,7 +122,9 @@ int kernel_text_address(unsigned long addr) { if (core_kernel_text(addr)) return 1; - return is_module_text_address(addr); + if (is_module_text_address(addr)) + return 1; + return is_ftrace_trampoline(addr); } /* diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 6233f9102179..fa0f36bb32e9 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1117,6 +1117,43 @@ static struct ftrace_ops global_ops = { FTRACE_OPS_FL_INITIALIZED, }; +/* + * This is used by __kernel_text_address() to return true if the + * the address is on a dynamically allocated trampoline that would + * not return true for either core_kernel_text() or + * is_module_text_address(). + */ +bool is_ftrace_trampoline(unsigned long addr) +{ + struct ftrace_ops *op; + bool ret = false; + + /* + * Some of the ops may be dynamically allocated, + * they are freed after a synchronize_sched(). + */ + preempt_disable_notrace(); + + do_for_each_ftrace_op(op, ftrace_ops_list) { + /* + * This is to check for dynamically allocated trampolines. + * Trampolines that are in kernel text will have + * core_kernel_text() return true. + */ + if (op->trampoline && op->trampoline_size) + if (addr >= op->trampoline && + addr < op->trampoline + op->trampoline_size) { + ret = true; + goto out; + } + } while_for_each_ftrace_op(op); + + out: + preempt_enable_notrace(); + + return ret; +} + struct ftrace_page { struct ftrace_page *next; struct dyn_ftrace *records; @@ -5373,6 +5410,7 @@ static struct ftrace_ops graph_ops = { FTRACE_OPS_FL_STUB, #ifdef FTRACE_GRAPH_TRAMP_ADDR .trampoline = FTRACE_GRAPH_TRAMP_ADDR, + /* trampoline_size is only needed for dynamically allocated tramps */ #endif ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash) }; |