diff options
Diffstat (limited to 'arch/x86/kernel/entry_32.S')
| -rw-r--r-- | arch/x86/kernel/entry_32.S | 80 |
1 files changed, 53 insertions, 27 deletions
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index f438a44bf8f..88b725aa1d5 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -57,6 +57,7 @@ #include <asm/cpufeature.h> #include <asm/alternative-asm.h> #include <asm/asm.h> +#include <asm/smap.h> /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */ #include <linux/elf-em.h> @@ -298,6 +299,21 @@ ENTRY(ret_from_fork) CFI_ENDPROC END(ret_from_fork) +ENTRY(ret_from_kernel_thread) + CFI_STARTPROC + pushl_cfi %eax + call schedule_tail + GET_THREAD_INFO(%ebp) + popl_cfi %eax + pushl_cfi $0x0202 # Reset kernel eflags + popfl_cfi + movl PT_EBP(%esp),%eax + call *PT_EBX(%esp) + movl $0,PT_EAX(%esp) + jmp syscall_exit + CFI_ENDPROC +ENDPROC(ret_from_kernel_thread) + /* * Interrupt exit functions should be protected against kprobes */ @@ -322,8 +338,7 @@ ret_from_intr: andl $(X86_EFLAGS_VM | SEGMENT_RPL_MASK), %eax #else /* - * We can be coming here from a syscall done in the kernel space, - * e.g. a failed kernel_execve(). + * We can be coming here from child spawned by kernel_thread(). */ movl PT_CS(%esp), %eax andl $SEGMENT_RPL_MASK, %eax @@ -407,7 +422,9 @@ sysenter_past_esp: */ cmpl $__PAGE_OFFSET-3,%ebp jae syscall_fault + ASM_STAC 1: movl (%ebp),%ebp + ASM_CLAC movl %ebp,PT_EBP(%esp) _ASM_EXTABLE(1b,syscall_fault) @@ -488,6 +505,7 @@ ENDPROC(ia32_sysenter_target) # system call handler stub ENTRY(system_call) RING0_INT_FRAME # can't unwind into user space anyway + ASM_CLAC pushl_cfi %eax # save orig_eax SAVE_ALL GET_THREAD_INFO(%ebp) @@ -612,6 +630,10 @@ work_notifysig: # deal with pending signals and movl %esp, %eax jne work_notifysig_v86 # returning to kernel-space or # vm86-space +1: +#else + movl %esp, %eax +#endif TRACE_IRQS_ON ENABLE_INTERRUPTS(CLBR_NONE) movb PT_CS(%esp), %bl @@ -622,24 +644,15 @@ work_notifysig: # deal with pending signals and call do_notify_resume jmp resume_userspace +#ifdef CONFIG_VM86 ALIGN work_notifysig_v86: pushl_cfi %ecx # save ti_flags for do_notify_resume call save_v86_state # %eax contains pt_regs pointer popl_cfi %ecx movl %eax, %esp -#else - movl %esp, %eax + jmp 1b #endif - TRACE_IRQS_ON - ENABLE_INTERRUPTS(CLBR_NONE) - movb PT_CS(%esp), %bl - andb $SEGMENT_RPL_MASK, %bl - cmpb $USER_RPL, %bl - jb resume_kernel - xorl %edx, %edx - call do_notify_resume - jmp resume_userspace END(work_pending) # perform syscall exit tracing @@ -670,6 +683,7 @@ END(syscall_exit_work) RING0_INT_FRAME # can't unwind into user space anyway syscall_fault: + ASM_CLAC GET_THREAD_INFO(%ebp) movl $-EFAULT,PT_EAX(%esp) jmp resume_userspace @@ -727,7 +741,6 @@ ENDPROC(ptregs_##name) PTREGSCALL1(iopl) PTREGSCALL0(fork) PTREGSCALL0(vfork) -PTREGSCALL3(execve) PTREGSCALL2(sigaltstack) PTREGSCALL0(sigreturn) PTREGSCALL0(rt_sigreturn) @@ -825,6 +838,7 @@ END(interrupt) */ .p2align CONFIG_X86_L1_CACHE_SHIFT common_interrupt: + ASM_CLAC addl $-0x80,(%esp) /* Adjust vector into the [-256,-1] range */ SAVE_ALL TRACE_IRQS_OFF @@ -841,6 +855,7 @@ ENDPROC(common_interrupt) #define BUILD_INTERRUPT3(name, nr, fn) \ ENTRY(name) \ RING0_INT_FRAME; \ + ASM_CLAC; \ pushl_cfi $~(nr); \ SAVE_ALL; \ TRACE_IRQS_OFF \ @@ -857,6 +872,7 @@ ENDPROC(name) ENTRY(coprocessor_error) RING0_INT_FRAME + ASM_CLAC pushl_cfi $0 pushl_cfi $do_coprocessor_error jmp error_code @@ -865,6 +881,7 @@ END(coprocessor_error) ENTRY(simd_coprocessor_error) RING0_INT_FRAME + ASM_CLAC pushl_cfi $0 #ifdef CONFIG_X86_INVD_BUG /* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */ @@ -886,6 +903,7 @@ END(simd_coprocessor_error) ENTRY(device_not_available) RING0_INT_FRAME + ASM_CLAC pushl_cfi $-1 # mark this as an int pushl_cfi $do_device_not_available jmp error_code @@ -906,6 +924,7 @@ END(native_irq_enable_sysexit) ENTRY(overflow) RING0_INT_FRAME + ASM_CLAC pushl_cfi $0 pushl_cfi $do_overflow jmp error_code @@ -914,6 +933,7 @@ END(overflow) ENTRY(bounds) RING0_INT_FRAME + ASM_CLAC pushl_cfi $0 pushl_cfi $do_bounds jmp error_code @@ -922,6 +942,7 @@ END(bounds) ENTRY(invalid_op) RING0_INT_FRAME + ASM_CLAC pushl_cfi $0 pushl_cfi $do_invalid_op jmp error_code @@ -930,6 +951,7 @@ END(invalid_op) ENTRY(coprocessor_segment_overrun) RING0_INT_FRAME + ASM_CLAC pushl_cfi $0 pushl_cfi $do_coprocessor_segment_overrun jmp error_code @@ -938,6 +960,7 @@ END(coprocessor_segment_overrun) ENTRY(invalid_TSS) RING0_EC_FRAME + ASM_CLAC pushl_cfi $do_invalid_TSS jmp error_code CFI_ENDPROC @@ -945,6 +968,7 @@ END(invalid_TSS) ENTRY(segment_not_present) RING0_EC_FRAME + ASM_CLAC pushl_cfi $do_segment_not_present jmp error_code CFI_ENDPROC @@ -952,6 +976,7 @@ END(segment_not_present) ENTRY(stack_segment) RING0_EC_FRAME + ASM_CLAC pushl_cfi $do_stack_segment jmp error_code CFI_ENDPROC @@ -959,6 +984,7 @@ END(stack_segment) ENTRY(alignment_check) RING0_EC_FRAME + ASM_CLAC pushl_cfi $do_alignment_check jmp error_code CFI_ENDPROC @@ -966,6 +992,7 @@ END(alignment_check) ENTRY(divide_error) RING0_INT_FRAME + ASM_CLAC pushl_cfi $0 # no error code pushl_cfi $do_divide_error jmp error_code @@ -975,6 +1002,7 @@ END(divide_error) #ifdef CONFIG_X86_MCE ENTRY(machine_check) RING0_INT_FRAME + ASM_CLAC pushl_cfi $0 pushl_cfi machine_check_vector jmp error_code @@ -984,6 +1012,7 @@ END(machine_check) ENTRY(spurious_interrupt_bug) RING0_INT_FRAME + ASM_CLAC pushl_cfi $0 pushl_cfi $do_spurious_interrupt_bug jmp error_code @@ -994,16 +1023,6 @@ END(spurious_interrupt_bug) */ .popsection -ENTRY(kernel_thread_helper) - pushl $0 # fake return address for unwinder - CFI_STARTPROC - movl %edi,%eax - call *%esi - call do_exit - ud2 # padding for call trace - CFI_ENDPROC -ENDPROC(kernel_thread_helper) - #ifdef CONFIG_XEN /* Xen doesn't set %esp to be precisely what the normal sysenter entrypoint expects, so fix it up before using the normal path. */ @@ -1016,7 +1035,7 @@ ENTRY(xen_sysenter_target) ENTRY(xen_hypervisor_callback) CFI_STARTPROC - pushl_cfi $0 + pushl_cfi $-1 /* orig_ax = -1 => not a system call */ SAVE_ALL TRACE_IRQS_OFF @@ -1058,14 +1077,16 @@ ENTRY(xen_failsafe_callback) 2: mov 8(%esp),%es 3: mov 12(%esp),%fs 4: mov 16(%esp),%gs + /* EAX == 0 => Category 1 (Bad segment) + EAX != 0 => Category 2 (Bad IRET) */ testl %eax,%eax popl_cfi %eax lea 16(%esp),%esp CFI_ADJUST_CFA_OFFSET -16 jz 5f addl $16,%esp - jmp iret_exc # EAX != 0 => Category 2 (Bad IRET) -5: pushl_cfi $0 # EAX == 0 => Category 1 (Bad segment) + jmp iret_exc +5: pushl_cfi $-1 /* orig_ax = -1 => not a system call */ SAVE_ALL jmp ret_from_exception CFI_ENDPROC @@ -1273,6 +1294,7 @@ return_to_handler: ENTRY(page_fault) RING0_EC_FRAME + ASM_CLAC pushl_cfi $do_page_fault ALIGN error_code: @@ -1345,6 +1367,7 @@ END(page_fault) ENTRY(debug) RING0_INT_FRAME + ASM_CLAC cmpl $ia32_sysenter_target,(%esp) jne debug_stack_correct FIX_STACK 12, debug_stack_correct, debug_esp_fix_insn @@ -1369,6 +1392,7 @@ END(debug) */ ENTRY(nmi) RING0_INT_FRAME + ASM_CLAC pushl_cfi %eax movl %ss, %eax cmpw $__ESPFIX_SS, %ax @@ -1439,6 +1463,7 @@ END(nmi) ENTRY(int3) RING0_INT_FRAME + ASM_CLAC pushl_cfi $-1 # mark this as an int SAVE_ALL TRACE_IRQS_OFF @@ -1459,6 +1484,7 @@ END(general_protection) #ifdef CONFIG_KVM_GUEST ENTRY(async_page_fault) RING0_EC_FRAME + ASM_CLAC pushl_cfi $do_async_page_fault jmp error_code CFI_ENDPROC |