diff options
Diffstat (limited to 'arch/x86/entry')
| -rw-r--r-- | arch/x86/entry/entry_64.S | 2 | ||||
| -rw-r--r-- | arch/x86/entry/entry_64_compat.S | 35 |
2 files changed, 34 insertions, 3 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 3bb2c4302df1..141a5d49dddc 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -613,7 +613,7 @@ ret_from_intr: testb $3, CS(%rsp) jz retint_kernel /* Interrupt came from user space */ -retint_user: +GLOBAL(retint_user) GET_THREAD_INFO(%rcx) /* %rcx: thread info. Interrupts are off. */ diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index b868cfc72985..e5ebdd963a99 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -428,8 +428,39 @@ cstar_tracesys: END(entry_SYSCALL_compat) ia32_badarg: - ASM_CLAC - movq $-EFAULT, RAX(%rsp) + /* + * So far, we've entered kernel mode, set AC, turned on IRQs, and + * saved C regs except r8-r11. We haven't done any of the other + * standard entry work, though. We want to bail, but we shouldn't + * treat this as a syscall entry since we don't even know what the + * args are. Instead, treat this as a non-syscall entry, finish + * the entry work, and immediately exit after setting AX = -EFAULT. + * + * We're really just being polite here. Killing the task outright + * would be a reasonable action, too. Given that the only valid + * way to have gotten here is through the vDSO, and we already know + * that the stack pointer is bad, the task isn't going to survive + * for long no matter what we do. + */ + + ASM_CLAC /* undo STAC */ + movq $-EFAULT, RAX(%rsp) /* return -EFAULT if possible */ + + /* Fill in the rest of pt_regs */ + xorl %eax, %eax + movq %rax, R11(%rsp) + movq %rax, R10(%rsp) + movq %rax, R9(%rsp) + movq %rax, R8(%rsp) + SAVE_EXTRA_REGS + + /* Turn IRQs back off. */ + DISABLE_INTERRUPTS(CLBR_NONE) + TRACE_IRQS_OFF + + /* And exit again. */ + jmp retint_user + ia32_ret_from_sys_call: xorl %eax, %eax /* Do not leak kernel information */ movq %rax, R11(%rsp) |