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Diffstat (limited to 'arch')
-rw-r--r--arch/x86_64/kernel/entry.S29
1 files changed, 18 insertions, 11 deletions
diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S
index 22cb6ee074b..7c10e9009d6 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