diff options
Diffstat (limited to 'arch/x86_64/kernel/entry.S')
| -rw-r--r-- | arch/x86_64/kernel/entry.S | 29 |
1 files changed, 18 insertions, 11 deletions
diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S index 22cb6ee..7c10e90 100644 --- a/arch/x86_64/kernel/entry.S +++ b/arch/x86_64/kernel/entry.S @@ -178,12 +178,6 @@ rff_trace: * Interrupts are off on entry. * Only called from user space. * - * EM64T CPUs have somewhat weird error reporting for non canonical RIPs in SYSRET. - * We can't handle any exceptions there because the exception handler would - * end up running on the user stack which is unsafe. To avoid problems - * any code that might end up with a user touched pt_regs should return - * using int_ret_from_syscall. - * * XXX if we had a free scratch register we could save the RSP into the stack frame * and report it properly in ps. Unfortunately we haven't. */ @@ -260,9 +254,7 @@ sysret_signal: xorl %esi,%esi # oldset -> arg2 call ptregscall_common 1: movl $_TIF_NEED_RESCHED,%edi - /* Stack frame might have been changed. The IRET path does - some additional checks to handle this */ - jmp int_with_check + jmp sysret_check badsys: movq $-ENOSYS,RAX-ARGOFFSET(%rsp) @@ -288,8 +280,7 @@ tracesys: call syscall_trace_leave RESTORE_TOP_OF_STACK %rbx RESTORE_REST - /* Stack frame might have been changed. Use the more careful IRET path */ - jmp int_ret_from_sys_call + jmp ret_from_sys_call CFI_ENDPROC /* @@ -417,9 +408,25 @@ ENTRY(stub_execve) CFI_ADJUST_CFA_OFFSET -8 CFI_REGISTER rip, r11 SAVE_REST + movq %r11, %r15 + CFI_REGISTER rip, r15 FIXUP_TOP_OF_STACK %r11 call sys_execve + GET_THREAD_INFO(%rcx) + bt $TIF_IA32,threadinfo_flags(%rcx) + CFI_REMEMBER_STATE + jc exec_32bit RESTORE_TOP_OF_STACK %r11 + movq %r15, %r11 + CFI_REGISTER rip, r11 + RESTORE_REST + pushq %r11 + CFI_ADJUST_CFA_OFFSET 8 + CFI_REL_OFFSET rip, 0 + ret + +exec_32bit: + CFI_RESTORE_STATE movq %rax,RAX(%rsp) RESTORE_REST jmp int_ret_from_sys_call |
