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

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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>
This commit is contained in:
Denys Vlasenko 2015-02-26 14:40:33 -08:00 committed by Ingo Molnar
parent b87cf63e2a
commit 1eeb207f87
1 changed files with 53 additions and 53 deletions
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106
arch/x86/kernel/entry_64.S
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@ -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