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authorPeter Zijlstra <peterz@infradead.org>2019-05-07 23:25:54 +0200
committerIngo Molnar <mingo@kernel.org>2019-06-25 10:23:47 +0200
commit3c88c692c28746473791276f8b42d2c989d6cbe6 (patch)
tree51cb03ef4cbb611f42ea43c8737be894991b656b /arch/x86/kernel/unwind_orc.c
parentea1ed38dba64b64a245ab8ca1406269d17b99485 (diff)
downloadlinux-3c88c692c28746473791276f8b42d2c989d6cbe6.tar.gz
x86/stackframe/32: Provide consistent pt_regs
Currently pt_regs on x86_32 has an oddity in that kernel regs
(!user_mode(regs)) are short two entries (esp/ss). This means that any
code trying to use them (typically: regs->sp) needs to jump through
some unfortunate hoops.

Change the entry code to fix this up and create a full pt_regs frame.

This then simplifies various trampolines in ftrace and kprobes, the
stack unwinder, ptrace, kdump and kgdb.

Much thanks to Josh for help with the cleanups!

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/unwind_orc.c')
-rw-r--r--arch/x86/kernel/unwind_orc.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
index 33b66b5c5aec..7f79aeebe3ee 100644
--- a/arch/x86/kernel/unwind_orc.c
+++ b/arch/x86/kernel/unwind_orc.c
@@ -580,7 +580,7 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task,
 			goto done;
 
 		state->ip = regs->ip;
-		state->sp = kernel_stack_pointer(regs);
+		state->sp = regs->sp;
 		state->bp = regs->bp;
 		state->regs = regs;
 		state->full_regs = true;