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author | Josh Poimboeuf <jpoimboe@redhat.com> | 2017-04-12 13:47:11 -0500 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2017-04-14 10:19:59 +0200 |
commit | 6bcdf9d51b9892dd5c6892d50cf5e9628efb8062 (patch) | |
tree | 79cc242c58b542dba3ecac6ec9255a014014bf5e /arch/x86/kernel/unwind_frame.c | |
parent | 5ed8d8bb38c5dcd78de540182cedb0fb19399aab (diff) | |
download | linux-6bcdf9d51b9892dd5c6892d50cf5e9628efb8062.tar.bz2 |
x86/unwind: Read stack return address in update_stack_state()
Instead of reading the return address when unwind_get_return_address()
is called, read it from update_stack_state() and store it in the unwind
state. This enables the next patch to check the return address from
unwind_next_frame() so it can detect an entry code frame.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/af0c5e4560c49c0343dca486ea26c4fa92bc4e35.1492020577.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/unwind_frame.c')
-rw-r--r-- | arch/x86/kernel/unwind_frame.c | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c index 9098ef1da8f8..c67a059c6655 100644 --- a/arch/x86/kernel/unwind_frame.c +++ b/arch/x86/kernel/unwind_frame.c @@ -56,20 +56,10 @@ static void unwind_dump(struct unwind_state *state, unsigned long *sp) unsigned long unwind_get_return_address(struct unwind_state *state) { - unsigned long addr; - unsigned long *addr_p = unwind_get_return_address_ptr(state); - if (unwind_done(state)) return 0; - if (state->regs && user_mode(state->regs)) - return 0; - - addr = READ_ONCE_TASK_STACK(state->task, *addr_p); - addr = ftrace_graph_ret_addr(state->task, &state->graph_idx, addr, - addr_p); - - return __kernel_text_address(addr) ? addr : 0; + return __kernel_text_address(state->ip) ? state->ip : 0; } EXPORT_SYMBOL_GPL(unwind_get_return_address); @@ -141,7 +131,7 @@ static bool update_stack_state(struct unwind_state *state, struct stack_info *info = &state->stack_info; enum stack_type prev_type = info->type; struct pt_regs *regs; - unsigned long *frame, *prev_frame_end; + unsigned long *frame, *prev_frame_end, *addr_p, addr; size_t len; if (state->regs) @@ -185,6 +175,16 @@ static bool update_stack_state(struct unwind_state *state, state->regs = NULL; } + /* Save the return address: */ + if (state->regs && user_mode(state->regs)) + state->ip = 0; + else { + addr_p = unwind_get_return_address_ptr(state); + addr = READ_ONCE_TASK_STACK(state->task, *addr_p); + state->ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, + addr, addr_p); + } + /* Save the original stack pointer for unwind_dump(): */ if (!state->orig_sp || info->type != prev_type) state->orig_sp = frame; @@ -228,6 +228,7 @@ bool unwind_next_frame(struct unwind_state *state) */ state->regs = regs; state->bp = NULL; + state->ip = 0; return true; } |