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author | Steven Rostedt <srostedt@redhat.com> | 2014-02-06 15:41:30 +0100 |
---|---|---|
committer | H. Peter Anvin <hpa@linux.intel.com> | 2014-03-07 01:56:54 +0100 |
commit | 0788aa6a23cb9d693fc5040ec774b979f1e906cd (patch) | |
tree | b1c5fd2dab9c0e11bc1747e5f6102d89d16dfcc0 /arch/x86/kernel/ptrace.c | |
parent | x86: Nuke GET_THREAD_INFO_WITH_ESP() macro for i386 (diff) | |
download | linux-0788aa6a23cb9d693fc5040ec774b979f1e906cd.tar.xz linux-0788aa6a23cb9d693fc5040ec774b979f1e906cd.zip |
x86: Prepare removal of previous_esp from i386 thread_info structure
The i386 thread_info contains a previous_esp field that is used
to daisy chain the different stacks for dump_stack()
(ie. irq, softirq, thread stacks).
The goal is to eventual make i386 handling of thread_info the same
as x86_64, which means that the thread_info will not be in the stack
but as a per_cpu variable. We will no longer depend on thread_info
being able to daisy chain different stacks as it will only exist
in one location (the thread stack).
By moving previous_esp to the end of thread_info and referencing
it as an offset instead of using a thread_info field, this becomes
a stepping stone to moving the thread_info.
The offset to get to the previous stack is rather ugly in this
patch, but this is only temporary and the prev_esp will be changed
in the next commit. This commit is more for sanity checks of the
change.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Robert Richter <rric@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20110806012353.891757693@goodmis.org
Link: http://lkml.kernel.org/r/20140206144321.608754481@goodmis.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/kernel/ptrace.c')
-rw-r--r-- | arch/x86/kernel/ptrace.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 7461f50d5bb1..f352a7cc43a1 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -184,14 +184,14 @@ unsigned long kernel_stack_pointer(struct pt_regs *regs) { unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1); unsigned long sp = (unsigned long)®s->sp; - struct thread_info *tinfo; + u32 *prev_esp; if (context == (sp & ~(THREAD_SIZE - 1))) return sp; - tinfo = (struct thread_info *)context; - if (tinfo->previous_esp) - return tinfo->previous_esp; + prev_esp = (u32 *)(context + sizeof(struct thread_info) - sizeof(long)); + if (prev_esp) + return (unsigned long)prev_esp; return (unsigned long)regs; } |