Messages in this thread Patch in this message | | | From | Denys Vlasenko <> | Subject | [PATCH 6/8] x86/asm/entry/64: simplify jumps in ret_from_fork | Date | Tue, 7 Apr 2015 22:43:42 +0200 |
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Replace test jz 1f jmp label 1:
with test jnz label
Run-tested.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> CC: Linus Torvalds <torvalds@linux-foundation.org> CC: Steven Rostedt <rostedt@goodmis.org> CC: Ingo Molnar <mingo@kernel.org> CC: Borislav Petkov <bp@alien8.de> CC: "H. Peter Anvin" <hpa@zytor.com> CC: Andy Lutomirski <luto@amacapital.net> CC: Oleg Nesterov <oleg@redhat.com> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Alexei Starovoitov <ast@plumgrid.com> CC: Will Drewry <wad@chromium.org> CC: Kees Cook <keescook@chromium.org> CC: x86@kernel.org CC: linux-kernel@vger.kernel.org --- arch/x86/kernel/entry_64.S | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 7d4c7c6..9915897 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -531,18 +531,18 @@ ENTRY(ret_from_fork) RESTORE_EXTRA_REGS testl $3,CS(%rsp) # from kernel_thread? - jz 1f /* * By the time we get here, we have no idea whether our pt_regs, * ti flags, and ti status came from the 64-bit SYSCALL fast path, * the slow path, or one of the ia32entry paths. - * Use int_ret_from_sys_call to return, since it can safely handle + * Use IRET code path to return, since it can safely handle * all of the above. */ - jmp int_ret_from_sys_call + jnz int_ret_from_sys_call -1: + /* We came from kernel_thread */ + /* nb: we depend on RESTORE_EXTRA_REGS above */ movq %rbp, %rdi call *%rbx movl $0, RAX(%rsp) -- 1.8.1.4
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