Messages in this thread | | | From | Linus Torvalds <> | Date | Thu, 16 Mar 2017 11:19:44 -0700 | Subject | Re: [PATCH 4/5 v3] ftrace/x86_32: Clean up ftrace_regs_caller |
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On Thu, Mar 16, 2017 at 11:09 AM, Steven Rostedt <rostedt@goodmis.org> wrote: > + > + /* Since we don't care about cs, move flags there to simplify return */ > + movl 14*4(%esp), %eax > + movl %eax, 13*4(%esp) > + > + /* Move return ip back to its original location */ > + movl 12*4(%esp), %eax > + movl %eax, 14*4(%esp)
Could this perhaps be removed entirely?
The return code could instead do:
... restore all the normal registers ..
# Now restore flags that is under the return address and our fake __KERNEL_CS pushl 8(%esp) popfl
# and then return, skipping __KERNEL_CS and %flasg ret $8
which is smaller and simpler than (again) playing games with stack entries.
Linus
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