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x86, um: convert to saner kernel_execve() semantics

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2012-10-10 21:35:42 -04:00
parent a74fb73c12
commit 22e2430d60
10 changed files with 21 additions and 68 deletions
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31
arch/x86/kernel/entry_32.S
View File

@@ -298,12 +298,20 @@ ENTRY(ret_from_fork)
CFI_ENDPROC
END(ret_from_fork)
ENTRY(ret_from_kernel_execve)
movl %eax, %esp
movl $0,PT_EAX(%esp)
ENTRY(ret_from_kernel_thread)
CFI_STARTPROC
pushl_cfi %eax
call schedule_tail
GET_THREAD_INFO(%ebp)
popl_cfi %eax
pushl_cfi $0x0202 # Reset kernel eflags
popfl_cfi
movl PT_EBP(%esp),%eax
call *PT_EBX(%esp)
movl $0,PT_EAX(%esp)
jmp syscall_exit
END(ret_from_kernel_execve)
CFI_ENDPROC
ENDPROC(ret_from_kernel_thread)
/*
* Interrupt exit functions should be protected against kprobes
@@ -994,21 +1002,6 @@ END(spurious_interrupt_bug)
*/
.popsection
ENTRY(ret_from_kernel_thread)
CFI_STARTPROC
pushl_cfi %eax
call schedule_tail
GET_THREAD_INFO(%ebp)
popl_cfi %eax
pushl_cfi $0x0202 # Reset kernel eflags
popfl_cfi
movl PT_EBP(%esp),%eax
call *PT_EBX(%esp)
call do_exit
ud2 # padding for call trace
CFI_ENDPROC
ENDPROC(ret_from_kernel_thread)
#ifdef CONFIG_XEN
/* Xen doesn't set %esp to be precisely what the normal sysenter
entrypoint expects, so fix it up before using the normal path. */

24
arch/x86/kernel/entry_64.S
View File

@@ -459,15 +459,13 @@ ENTRY(ret_from_fork)
jmp ret_from_sys_call # go to the SYSRET fastpath
1:
subq $REST_SKIP, %rsp # move the stack pointer back
subq $REST_SKIP, %rsp # leave space for volatiles
CFI_ADJUST_CFA_OFFSET REST_SKIP
movq %rbp, %rdi
call *%rbx
# exit
mov %eax, %edi
call do_exit
ud2 # padding for call trace
movl $0, RAX(%rsp)
RESTORE_REST
jmp int_ret_from_sys_call
CFI_ENDPROC
END(ret_from_fork)
@@ -1214,20 +1212,6 @@ bad_gs:
jmp 2b
.previous
ENTRY(ret_from_kernel_execve)
movq %rdi, %rsp
movl $0, RAX(%rsp)
// RESTORE_REST
movq 0*8(%rsp), %r15
movq 1*8(%rsp), %r14
movq 2*8(%rsp), %r13
movq 3*8(%rsp), %r12
movq 4*8(%rsp), %rbp
movq 5*8(%rsp), %rbx
addq $(6*8), %rsp
jmp int_ret_from_sys_call
END(ret_from_kernel_execve)
/* Call softirq on interrupt stack. Interrupts are off. */
ENTRY(call_softirq)
CFI_STARTPROC