diff options
Diffstat (limited to 'arch/sh/kernel/dwarf.c')
| -rw-r--r-- | arch/sh/kernel/dwarf.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/arch/sh/kernel/dwarf.c b/arch/sh/kernel/dwarf.c index 03b3616c80a5..d76a23170dbb 100644 --- a/arch/sh/kernel/dwarf.c +++ b/arch/sh/kernel/dwarf.c @@ -20,6 +20,7 @@ #include <linux/list.h> #include <linux/mempool.h> #include <linux/mm.h> +#include <linux/ftrace.h> #include <asm/dwarf.h> #include <asm/unwinder.h> #include <asm/sections.h> @@ -554,9 +555,30 @@ struct dwarf_frame * dwarf_unwind_stack(unsigned long pc, * NOTE: the return address is guaranteed to be setup by the * time this function makes its first function call. */ - if (!pc && !prev) + if (!pc || !prev) pc = (unsigned long)current_text_addr(); +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + /* + * If our stack has been patched by the function graph tracer + * then we might see the address of return_to_handler() where we + * expected to find the real return address. + */ + if (pc == (unsigned long)&return_to_handler) { + int index = current->curr_ret_stack; + + /* + * We currently have no way of tracking how many + * return_to_handler()'s we've seen. If there is more + * than one patched return address on our stack, + * complain loudly. + */ + WARN_ON(index > 0); + + pc = current->ret_stack[index].ret; + } +#endif + frame = mempool_alloc(dwarf_frame_pool, GFP_ATOMIC); if (!frame) { printk(KERN_ERR "Unable to allocate a dwarf frame\n"); |