diff options
Diffstat (limited to 'arch/x86/kernel/entry_64.S')
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 74 |
1 files changed, 25 insertions, 49 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 44531acd9a81..cdc790c78f32 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -554,7 +554,7 @@ ENTRY(ret_from_fork) RESTORE_REST testl $3, CS-ARGOFFSET(%rsp) # from kernel_thread? - jz retint_restore_args + jz 1f testl $_TIF_IA32, TI_flags(%rcx) # 32-bit compat task needs IRET jnz int_ret_from_sys_call @@ -562,6 +562,16 @@ ENTRY(ret_from_fork) RESTORE_TOP_OF_STACK %rdi, -ARGOFFSET jmp ret_from_sys_call # go to the SYSRET fastpath +1: + subq $REST_SKIP, %rsp # move the stack pointer back + CFI_ADJUST_CFA_OFFSET REST_SKIP + movq %rbp, %rdi + call *%rbx + # exit + mov %eax, %edi + call do_exit + ud2 # padding for call trace + CFI_ENDPROC END(ret_from_fork) @@ -862,7 +872,6 @@ ENTRY(stub_execve) 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) @@ -912,8 +921,7 @@ ENTRY(stub_x32_execve) 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 @@ -1318,51 +1326,19 @@ bad_gs: jmp 2b .previous -ENTRY(kernel_thread_helper) - pushq $0 # fake return address - CFI_STARTPROC - /* - * Here we are in the child and the registers are set as they were - * at kernel_thread() invocation in the parent. - */ - call *%rsi - # exit - mov %eax, %edi - call do_exit - ud2 # padding for call trace - CFI_ENDPROC -END(kernel_thread_helper) - -/* - * 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) |