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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-20 21:24:49 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-20 21:24:49 +0300 |
commit | c6dd78fcb8eefa15dd861889e0f59d301cb5230c (patch) | |
tree | 0ff947de7cd07590d2735f7add164f0bbda1c840 /arch/x86/entry | |
parent | 46f5c0cc3af0ecb76224a91d2997d74e35ff7821 (diff) | |
parent | 6879298bd0673840cadd1fb36d7225485504ceb4 (diff) | |
download | linux-c6dd78fcb8eefa15dd861889e0f59d301cb5230c.tar.xz |
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A set of x86 specific fixes and updates:
- The CR2 corruption fixes which store CR2 early in the entry code
and hand the stored address to the fault handlers.
- Revert a forgotten leftover of the dropped FSGSBASE series.
- Plug a memory leak in the boot code.
- Make the Hyper-V assist functionality robust by zeroing the shadow
page.
- Remove a useless check for dead processes with LDT
- Update paravirt and VMware maintainers entries.
- A few cleanup patches addressing various compiler warnings"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/entry/64: Prevent clobbering of saved CR2 value
x86/hyper-v: Zero out the VP ASSIST PAGE on allocation
x86, boot: Remove multiple copy of static function sanitize_boot_params()
x86/boot/compressed/64: Remove unused variable
x86/boot/efi: Remove unused variables
x86/mm, tracing: Fix CR2 corruption
x86/entry/64: Update comments and sanity tests for create_gap
x86/entry/64: Simplify idtentry a little
x86/entry/32: Simplify common_exception
x86/paravirt: Make read_cr2() CALLEE_SAVE
MAINTAINERS: Update PARAVIRT_OPS_INTERFACE and VMWARE_HYPERVISOR_INTERFACE
x86/process: Delete useless check for dead process with LDT
x86: math-emu: Hide clang warnings for 16-bit overflow
x86/e820: Use proper booleans instead of 0/1
x86/apic: Silence -Wtype-limits compiler warnings
x86/mm: Free sme_early_buffer after init
x86/boot: Fix memory leak in default_get_smp_config()
Revert "x86/ptrace: Prevent ptrace from clearing the FS/GS selector" and fix the test
Diffstat (limited to 'arch/x86/entry')
-rw-r--r-- | arch/x86/entry/calling.h | 6 | ||||
-rw-r--r-- | arch/x86/entry/entry_32.S | 61 | ||||
-rw-r--r-- | arch/x86/entry/entry_64.S | 155 |
3 files changed, 123 insertions, 99 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index 9f1f9e3b8230..830bd984182b 100644 --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -343,3 +343,9 @@ For 32-bit we have the following conventions - kernel is built with .Lafter_call_\@: #endif .endm + +#ifdef CONFIG_PARAVIRT_XXL +#define GET_CR2_INTO(reg) GET_CR2_INTO_AX ; _ASM_MOV %_ASM_AX, reg +#else +#define GET_CR2_INTO(reg) _ASM_MOV %cr2, reg +#endif diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 90b473297299..2bb986f305ac 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -294,9 +294,11 @@ .Lfinished_frame_\@: .endm -.macro SAVE_ALL pt_regs_ax=%eax switch_stacks=0 +.macro SAVE_ALL pt_regs_ax=%eax switch_stacks=0 skip_gs=0 cld +.if \skip_gs == 0 PUSH_GS +.endif FIXUP_FRAME pushl %fs pushl %es @@ -313,13 +315,13 @@ movl %edx, %es movl $(__KERNEL_PERCPU), %edx movl %edx, %fs +.if \skip_gs == 0 SET_KERNEL_GS %edx - +.endif /* Switch to kernel stack if necessary */ .if \switch_stacks > 0 SWITCH_TO_KERNEL_STACK .endif - .endm .macro SAVE_ALL_NMI cr3_reg:req @@ -1441,39 +1443,46 @@ BUILD_INTERRUPT3(hv_stimer0_callback_vector, HYPERV_STIMER0_VECTOR, ENTRY(page_fault) ASM_CLAC - pushl $do_page_fault - ALIGN - jmp common_exception + pushl $0; /* %gs's slot on the stack */ + + SAVE_ALL switch_stacks=1 skip_gs=1 + + ENCODE_FRAME_POINTER + UNWIND_ESPFIX_STACK + + /* fixup %gs */ + GS_TO_REG %ecx + REG_TO_PTGS %ecx + SET_KERNEL_GS %ecx + + GET_CR2_INTO(%ecx) # might clobber %eax + + /* fixup orig %eax */ + movl PT_ORIG_EAX(%esp), %edx # get the error code + movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart + + TRACE_IRQS_OFF + movl %esp, %eax # pt_regs pointer + call do_page_fault + jmp ret_from_exception END(page_fault) common_exception: /* the function address is in %gs's slot on the stack */ - FIXUP_FRAME - pushl %fs - pushl %es - pushl %ds - pushl %eax - movl $(__USER_DS), %eax - movl %eax, %ds - movl %eax, %es - movl $(__KERNEL_PERCPU), %eax - movl %eax, %fs - pushl %ebp - pushl %edi - pushl %esi - pushl %edx - pushl %ecx - pushl %ebx - SWITCH_TO_KERNEL_STACK + SAVE_ALL switch_stacks=1 skip_gs=1 ENCODE_FRAME_POINTER - cld UNWIND_ESPFIX_STACK + + /* fixup %gs */ GS_TO_REG %ecx movl PT_GS(%esp), %edi # get the function address - movl PT_ORIG_EAX(%esp), %edx # get the error code - movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart REG_TO_PTGS %ecx SET_KERNEL_GS %ecx + + /* fixup orig %eax */ + movl PT_ORIG_EAX(%esp), %edx # get the error code + movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart + TRACE_IRQS_OFF movl %esp, %eax # pt_regs pointer CALL_NOSPEC %edi diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 35a66fcfcb91..3f5a978a02a7 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -864,18 +864,84 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt */ #define CPU_TSS_IST(x) PER_CPU_VAR(cpu_tss_rw) + (TSS_ist + (x) * 8) +.macro idtentry_part do_sym, has_error_code:req, read_cr2:req, paranoid:req, shift_ist=-1, ist_offset=0 + + .if \paranoid + call paranoid_entry + /* returned flag: ebx=0: need swapgs on exit, ebx=1: don't need it */ + .else + call error_entry + .endif + UNWIND_HINT_REGS + + .if \read_cr2 + /* + * Store CR2 early so subsequent faults cannot clobber it. Use R12 as + * intermediate storage as RDX can be clobbered in enter_from_user_mode(). + * GET_CR2_INTO can clobber RAX. + */ + GET_CR2_INTO(%r12); + .endif + + .if \shift_ist != -1 + TRACE_IRQS_OFF_DEBUG /* reload IDT in case of recursion */ + .else + TRACE_IRQS_OFF + .endif + + .if \paranoid == 0 + testb $3, CS(%rsp) + jz .Lfrom_kernel_no_context_tracking_\@ + CALL_enter_from_user_mode +.Lfrom_kernel_no_context_tracking_\@: + .endif + + movq %rsp, %rdi /* pt_regs pointer */ + + .if \has_error_code + movq ORIG_RAX(%rsp), %rsi /* get error code */ + movq $-1, ORIG_RAX(%rsp) /* no syscall to restart */ + .else + xorl %esi, %esi /* no error code */ + .endif + + .if \shift_ist != -1 + subq $\ist_offset, CPU_TSS_IST(\shift_ist) + .endif + + .if \read_cr2 + movq %r12, %rdx /* Move CR2 into 3rd argument */ + .endif + + call \do_sym + + .if \shift_ist != -1 + addq $\ist_offset, CPU_TSS_IST(\shift_ist) + .endif + + .if \paranoid + /* this procedure expect "no swapgs" flag in ebx */ + jmp paranoid_exit + .else + jmp error_exit + .endif + +.endm + /** * idtentry - Generate an IDT entry stub * @sym: Name of the generated entry point - * @do_sym: C function to be called - * @has_error_code: True if this IDT vector has an error code on the stack - * @paranoid: non-zero means that this vector may be invoked from + * @do_sym: C function to be called + * @has_error_code: True if this IDT vector has an error code on the stack + * @paranoid: non-zero means that this vector may be invoked from * kernel mode with user GSBASE and/or user CR3. * 2 is special -- see below. * @shift_ist: Set to an IST index if entries from kernel mode should - * decrement the IST stack so that nested entries get a + * decrement the IST stack so that nested entries get a * fresh stack. (This is for #DB, which has a nasty habit - * of recursing.) + * of recursing.) + * @create_gap: create a 6-word stack gap when coming from kernel mode. + * @read_cr2: load CR2 into the 3rd argument; done before calling any C code * * idtentry generates an IDT stub that sets up a usable kernel context, * creates struct pt_regs, and calls @do_sym. The stub has the following @@ -900,15 +966,19 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt * @paranoid == 2 is special: the stub will never switch stacks. This is for * #DF: if the thread stack is somehow unusable, we'll still get a useful OOPS. */ -.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1 ist_offset=0 create_gap=0 +.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1 ist_offset=0 create_gap=0 read_cr2=0 ENTRY(\sym) UNWIND_HINT_IRET_REGS offset=\has_error_code*8 /* Sanity check */ - .if \shift_ist != -1 && \paranoid == 0 + .if \shift_ist != -1 && \paranoid != 1 .error "using shift_ist requires paranoid=1" .endif + .if \create_gap && \paranoid + .error "using create_gap requires paranoid=0" + .endif + ASM_CLAC .if \has_error_code == 0 @@ -934,47 +1004,7 @@ ENTRY(\sym) .Lfrom_usermode_no_gap_\@: .endif - .if \paranoid - call paranoid_entry - .else - call error_entry - .endif - UNWIND_HINT_REGS - /* returned flag: ebx=0: need swapgs on exit, ebx=1: don't need it */ - - .if \paranoid - .if \shift_ist != -1 - TRACE_IRQS_OFF_DEBUG /* reload IDT in case of recursion */ - .else - TRACE_IRQS_OFF - .endif - .endif - - movq %rsp, %rdi /* pt_regs pointer */ - - .if \has_error_code - movq ORIG_RAX(%rsp), %rsi /* get error code */ - movq $-1, ORIG_RAX(%rsp) /* no syscall to restart */ - .else - xorl %esi, %esi /* no error code */ - .endif - - .if \shift_ist != -1 - subq $\ist_offset, CPU_TSS_IST(\shift_ist) - .endif - - call \do_sym - - .if \shift_ist != -1 - addq $\ist_offset, CPU_TSS_IST(\shift_ist) - .endif - - /* these procedures expect "no swapgs" flag in ebx */ - .if \paranoid - jmp paranoid_exit - .else - jmp error_exit - .endif + idtentry_part \do_sym, \has_error_code, \read_cr2, \paranoid, \shift_ist, \ist_offset .if \paranoid == 1 /* @@ -983,21 +1013,9 @@ ENTRY(\sym) * run in real process context if user_mode(regs). */ .Lfrom_usermode_switch_stack_\@: - call error_entry - - movq %rsp, %rdi /* pt_regs pointer */ - - .if \has_error_code - movq ORIG_RAX(%rsp), %rsi /* get error code */ - movq $-1, ORIG_RAX(%rsp) /* no syscall to restart */ - .else - xorl %esi, %esi /* no error code */ + idtentry_part \do_sym, \has_error_code, \read_cr2, paranoid=0 .endif - call \do_sym - - jmp error_exit - .endif _ASM_NOKPROBE(\sym) END(\sym) .endm @@ -1007,7 +1025,7 @@ idtentry overflow do_overflow has_error_code=0 idtentry bounds do_bounds has_error_code=0 idtentry invalid_op do_invalid_op has_error_code=0 idtentry device_not_available do_device_not_available has_error_code=0 -idtentry double_fault do_double_fault has_error_code=1 paranoid=2 +idtentry double_fault do_double_fault has_error_code=1 paranoid=2 read_cr2=1 idtentry coprocessor_segment_overrun do_coprocessor_segment_overrun has_error_code=0 idtentry invalid_TSS do_invalid_TSS has_error_code=1 idtentry segment_not_present do_segment_not_present has_error_code=1 @@ -1179,10 +1197,10 @@ idtentry xendebug do_debug has_error_code=0 #endif idtentry general_protection do_general_protection has_error_code=1 -idtentry page_fault do_page_fault has_error_code=1 +idtentry page_fault do_page_fault has_error_code=1 read_cr2=1 #ifdef CONFIG_KVM_GUEST -idtentry async_page_fault do_async_page_fault has_error_code=1 +idtentry async_page_fault do_async_page_fault has_error_code=1 read_cr2=1 #endif #ifdef CONFIG_X86_MCE @@ -1281,18 +1299,9 @@ ENTRY(error_entry) movq %rax, %rsp /* switch stack */ ENCODE_FRAME_POINTER pushq %r12 - - /* - * We need to tell lockdep that IRQs are off. We can't do this until - * we fix gsbase, and we should do it before enter_from_user_mode - * (which can take locks). - */ - TRACE_IRQS_OFF - CALL_enter_from_user_mode ret .Lerror_entry_done: - TRACE_IRQS_OFF ret /* |