x86, um/x86: switch to generic sys_execve and kernel_execve
32bit wrapper is lost on that; 64bit one is *not*, since
we need to arrange for full pt_regs on stack when we call
sys_execve() and we need to load callee-saved ones from
there afterwards.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 5526d17..053c955 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -767,7 +767,6 @@
PARTIAL_FRAME 0
SAVE_REST
FIXUP_TOP_OF_STACK %r11
- movq %rsp, %rcx
call sys_execve
RESTORE_TOP_OF_STACK %r11
movq %rax,RAX(%rsp)
@@ -817,8 +816,7 @@
PARTIAL_FRAME 0
SAVE_REST
FIXUP_TOP_OF_STACK %r11
- movq %rsp, %rcx
- call sys32_execve
+ call compat_sys_execve
RESTORE_TOP_OF_STACK %r11
movq %rax,RAX(%rsp)
RESTORE_REST
@@ -1216,36 +1214,19 @@
jmp 2b
.previous
-/*
- * execve(). This function needs to use IRET, not SYSRET, to set up all state properly.
- *
- * C extern interface:
- * extern long execve(const char *name, char **argv, char **envp)
- *
- * asm input arguments:
- * rdi: name, rsi: argv, rdx: envp
- *
- * We want to fallback into:
- * extern long sys_execve(const char *name, char **argv,char **envp, struct pt_regs *regs)
- *
- * do_sys_execve asm fallback arguments:
- * rdi: name, rsi: argv, rdx: envp, rcx: fake frame on the stack
- */
-ENTRY(kernel_execve)
- CFI_STARTPROC
- FAKE_STACK_FRAME $0
- SAVE_ALL
- movq %rsp,%rcx
- call sys_execve
- movq %rax, RAX(%rsp)
- RESTORE_REST
- testq %rax,%rax
- je int_ret_from_sys_call
- RESTORE_ARGS
- UNFAKE_STACK_FRAME
- ret
- CFI_ENDPROC
-END(kernel_execve)
+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)
