x86/asm/entry/64: Move 'save_paranoid' and 'ret_from_fork' closer to their users

For some odd reason, these two functions are at the very top of
the file. "save_paranoid"'s caller is approximately in the middle
of it, move it there. Move 'ret_from_fork' to be right after
fork/exec helpers.

This is a pure block move, nothing is changed in the function
bodies.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/6446bbfe4094532623a5b83779b7015fec167a9d.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index e5cbfbbf94793d4d46d65cb572ac9fcad144f04d..9e33d492ace398d9920ef0803f989f7e492d6309 100644 (file)
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -202,59 +202,6 @@ ENDPROC(native_usergs_sysret64)
        CFI_REL_OFFSET r15, R15+\offset
        .endm
 
-ENTRY(save_paranoid)
-       XCPT_FRAME 1 RDI+8
-       cld
-       SAVE_C_REGS 8
-       SAVE_EXTRA_REGS 8
-       movl $1,%ebx
-       movl $MSR_GS_BASE,%ecx
-       rdmsr
-       testl %edx,%edx
-       js 1f   /* negative -> in kernel */
-       SWAPGS
-       xorl %ebx,%ebx
-1:     ret
-       CFI_ENDPROC
-END(save_paranoid)
-
-/*
- * A newly forked process directly context switches into this address.
- *
- * rdi: prev task we switched from
- */
-ENTRY(ret_from_fork)
-       DEFAULT_FRAME
-
-       LOCK ; btr $TIF_FORK,TI_flags(%r8)
-
-       pushq_cfi $0x0002
-       popfq_cfi                               # reset kernel eflags
-
-       call schedule_tail                      # rdi: 'prev' task parameter
-
-       GET_THREAD_INFO(%rcx)
-
-       RESTORE_EXTRA_REGS
-
-       testl $3,CS(%rsp)                       # from kernel_thread?
-       jz   1f
-
-       testl $_TIF_IA32, TI_flags(%rcx)        # 32-bit compat task needs IRET
-       jnz  int_ret_from_sys_call
-
-       RESTORE_TOP_OF_STACK %rdi
-       jmp ret_from_sys_call                   # go to the SYSRET fastpath
-
-1:
-       movq %rbp, %rdi
-       call *%rbx
-       movl $0, RAX(%rsp)
-       RESTORE_EXTRA_REGS
-       jmp int_ret_from_sys_call
-       CFI_ENDPROC
-END(ret_from_fork)
-
 /*
  * 64bit SYSCALL instruction entry. Up to 6 arguments in registers.
  *
@@ -581,6 +528,43 @@ END(stub_x32_execveat)
 
 #endif
 
+/*
+ * A newly forked process directly context switches into this address.
+ *
+ * rdi: prev task we switched from
+ */
+ENTRY(ret_from_fork)
+       DEFAULT_FRAME
+
+       LOCK ; btr $TIF_FORK,TI_flags(%r8)
+
+       pushq_cfi $0x0002
+       popfq_cfi                               # reset kernel eflags
+
+       call schedule_tail                      # rdi: 'prev' task parameter
+
+       GET_THREAD_INFO(%rcx)
+
+       RESTORE_EXTRA_REGS
+
+       testl $3,CS(%rsp)                       # from kernel_thread?
+       jz   1f
+
+       testl $_TIF_IA32, TI_flags(%rcx)        # 32-bit compat task needs IRET
+       jnz  int_ret_from_sys_call
+
+       RESTORE_TOP_OF_STACK %rdi
+       jmp ret_from_sys_call                   # go to the SYSRET fastpath
+
+1:
+       movq %rbp, %rdi
+       call *%rbx
+       movl $0, RAX(%rsp)
+       RESTORE_EXTRA_REGS
+       jmp int_ret_from_sys_call
+       CFI_ENDPROC
+END(ret_from_fork)
+
 /*
  * Build the entry stubs and pointer table with some assembler magic.
  * We pack 7 stubs into a single 32-byte chunk, which will fit in a
@@ -1273,6 +1257,22 @@ idtentry async_page_fault do_async_page_fault has_error_code=1
 idtentry machine_check has_error_code=0 paranoid=1 do_sym=*machine_check_vector(%rip)
 #endif
 
+ENTRY(save_paranoid)
+       XCPT_FRAME 1 RDI+8
+       cld
+       SAVE_C_REGS 8
+       SAVE_EXTRA_REGS 8
+       movl $1,%ebx
+       movl $MSR_GS_BASE,%ecx
+       rdmsr
+       testl %edx,%edx
+       js 1f   /* negative -> in kernel */
+       SWAPGS
+       xorl %ebx,%ebx
+1:     ret
+       CFI_ENDPROC
+END(save_paranoid)
+
        /*
         * "Paranoid" exit path from exception stack.  This is invoked
         * only on return from non-NMI IST interrupts that came