diff options
Diffstat (limited to 'arch/x86/entry/entry_32.S')
| -rw-r--r-- | arch/x86/entry/entry_32.S | 70 |
1 files changed, 22 insertions, 48 deletions
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 91397f58ac30..92c0b4a94e0a 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -305,7 +305,7 @@ .macro CHECK_AND_APPLY_ESPFIX #ifdef CONFIG_X86_ESPFIX32 #define GDT_ESPFIX_OFFSET (GDT_ENTRY_ESPFIX_SS * 8) -#define GDT_ESPFIX_SS PER_CPU_VAR(gdt_page) + GDT_ESPFIX_OFFSET +#define GDT_ESPFIX_SS PER_CPU_VAR(gdt_page + GDT_ESPFIX_OFFSET) ALTERNATIVE "jmp .Lend_\@", "", X86_BUG_ESPFIX @@ -649,10 +649,6 @@ SYM_CODE_START_LOCAL(asm_\cfunc) SYM_CODE_END(asm_\cfunc) .endm -.macro idtentry_sysvec vector cfunc - idtentry \vector asm_\cfunc \cfunc has_error_code=0 -.endm - /* * Include the defines which emit the idt entries which are shared * shared between 32 and 64 bit and emit the __irqentry_text_* markers @@ -720,26 +716,6 @@ SYM_CODE_END(__switch_to_asm) .popsection /* - * The unwinder expects the last frame on the stack to always be at the same - * offset from the end of the page, which allows it to validate the stack. - * Calling schedule_tail() directly would break that convention because its an - * asmlinkage function so its argument has to be pushed on the stack. This - * wrapper creates a proper "end of stack" frame header before the call. - */ -.pushsection .text, "ax" -SYM_FUNC_START(schedule_tail_wrapper) - FRAME_BEGIN - - pushl %eax - call schedule_tail - popl %eax - - FRAME_END - RET -SYM_FUNC_END(schedule_tail_wrapper) -.popsection - -/* * A newly forked process directly context switches into this address. * * eax: prev task we switched from @@ -747,29 +723,22 @@ SYM_FUNC_END(schedule_tail_wrapper) * edi: kernel thread arg */ .pushsection .text, "ax" -SYM_CODE_START(ret_from_fork) - call schedule_tail_wrapper +SYM_CODE_START(ret_from_fork_asm) + movl %esp, %edx /* regs */ - testl %ebx, %ebx - jnz 1f /* kernel threads are uncommon */ + /* return address for the stack unwinder */ + pushl $.Lsyscall_32_done -2: - /* When we fork, we trace the syscall return in the child, too. */ - movl %esp, %eax - call syscall_exit_to_user_mode - jmp .Lsyscall_32_done + FRAME_BEGIN + /* prev already in EAX */ + movl %ebx, %ecx /* fn */ + pushl %edi /* fn_arg */ + call ret_from_fork + addl $4, %esp + FRAME_END - /* kernel thread */ -1: movl %edi, %eax - CALL_NOSPEC ebx - /* - * A kernel thread is allowed to return here after successfully - * calling kernel_execve(). Exit to userspace to complete the execve() - * syscall. - */ - movl $0, PT_EAX(%esp) - jmp 2b -SYM_CODE_END(ret_from_fork) + RET +SYM_CODE_END(ret_from_fork_asm) .popsection SYM_ENTRY(__begin_SYSENTER_singlestep_region, SYM_L_GLOBAL, SYM_A_NONE) @@ -864,7 +833,7 @@ SYM_FUNC_START(entry_SYSENTER_32) movl %esp, %eax call do_SYSENTER_32 - testl %eax, %eax + testb %al, %al jz .Lsyscall_32_done STACKLEAK_ERASE @@ -902,6 +871,8 @@ SYM_FUNC_START(entry_SYSENTER_32) /* Now ready to switch the cr3 */ SWITCH_TO_USER_CR3 scratch_reg=%eax + /* Clobbers ZF */ + CLEAR_CPU_BUFFERS /* * Restore all flags except IF. (We restore IF separately because @@ -981,6 +952,7 @@ restore_all_switch_stack: /* Restore user state */ RESTORE_REGS pop=4 # skip orig_eax/error_code + CLEAR_CPU_BUFFERS .Lirq_return: /* * ARCH_HAS_MEMBARRIER_SYNC_CORE rely on IRET core serialization @@ -1181,7 +1153,7 @@ SYM_CODE_START(asm_exc_nmi) * is using the thread stack right now, so it's safe for us to use it. */ movl %esp, %ebx - movl PER_CPU_VAR(pcpu_hot + X86_top_of_stack), %esp + movl PER_CPU_VAR(cpu_current_top_of_stack), %esp call exc_nmi movl %ebx, %esp @@ -1193,6 +1165,7 @@ SYM_CODE_START(asm_exc_nmi) CHECK_AND_APPLY_ESPFIX RESTORE_ALL_NMI cr3_reg=%edi pop=4 + CLEAR_CPU_BUFFERS jmp .Lirq_return #ifdef CONFIG_X86_ESPFIX32 @@ -1234,6 +1207,7 @@ SYM_CODE_START(asm_exc_nmi) * 1 - orig_ax */ lss (1+5+6)*4(%esp), %esp # back to espfix stack + CLEAR_CPU_BUFFERS jmp .Lirq_return #endif SYM_CODE_END(asm_exc_nmi) @@ -1243,7 +1217,7 @@ SYM_CODE_START(rewind_stack_and_make_dead) /* Prevent any naive code from trying to unwind to our caller. */ xorl %ebp, %ebp - movl PER_CPU_VAR(pcpu_hot + X86_top_of_stack), %esi + movl PER_CPU_VAR(cpu_current_top_of_stack), %esi leal -TOP_OF_KERNEL_STACK_PADDING-PTREGS_SIZE(%esi), %esp call make_task_dead |