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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-14 17:02:15 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-14 17:02:15 -0800 |
commit | d4667ca142610961c89ae7c41a823b3358fcdd0e (patch) | |
tree | ff43d39e20feaf477a1ceaf35eba841eebd7e0a6 /arch/x86/entry/entry_64.S | |
parent | 6556677a80400ca5744340d8ff6fbed22621293e (diff) | |
parent | e48657573481a5dff7cfdc3d57005c80aa816500 (diff) | |
download | linux-d4667ca142610961c89ae7c41a823b3358fcdd0e.tar.bz2 |
Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 PTI and Spectre related fixes and updates from Ingo Molnar:
"Here's the latest set of Spectre and PTI related fixes and updates:
Spectre:
- Add entry code register clearing to reduce the Spectre attack
surface
- Update the Spectre microcode blacklist
- Inline the KVM Spectre helpers to get close to v4.14 performance
again.
- Fix indirect_branch_prediction_barrier()
- Fix/improve Spectre related kernel messages
- Fix array_index_nospec_mask() asm constraint
- KVM: fix two MSR handling bugs
PTI:
- Fix a paranoid entry PTI CR3 handling bug
- Fix comments
objtool:
- Fix paranoid_entry() frame pointer warning
- Annotate WARN()-related UD2 as reachable
- Various fixes
- Add Add Peter Zijlstra as objtool co-maintainer
Misc:
- Various x86 entry code self-test fixes
- Improve/simplify entry code stack frame generation and handling
after recent heavy-handed PTI and Spectre changes. (There's two
more WIP improvements expected here.)
- Type fix for cache entries
There's also some low risk non-fix changes I've included in this
branch to reduce backporting conflicts:
- rename a confusing x86_cpu field name
- de-obfuscate the naming of single-TLB flushing primitives"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
x86/entry/64: Fix CR3 restore in paranoid_exit()
x86/cpu: Change type of x86_cache_size variable to unsigned int
x86/spectre: Fix an error message
x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping
selftests/x86/mpx: Fix incorrect bounds with old _sigfault
x86/mm: Rename flush_tlb_single() and flush_tlb_one() to __flush_tlb_one_[user|kernel]()
x86/speculation: Add <asm/msr-index.h> dependency
nospec: Move array_index_nospec() parameter checking into separate macro
x86/speculation: Fix up array_index_nospec_mask() asm constraint
x86/debug: Use UD2 for WARN()
x86/debug, objtool: Annotate WARN()-related UD2 as reachable
objtool: Fix segfault in ignore_unreachable_insn()
selftests/x86: Disable tests requiring 32-bit support on pure 64-bit systems
selftests/x86: Do not rely on "int $0x80" in single_step_syscall.c
selftests/x86: Do not rely on "int $0x80" in test_mremap_vdso.c
selftests/x86: Fix build bug caused by the 5lvl test which has been moved to the VM directory
selftests/x86/pkeys: Remove unused functions
selftests/x86: Clean up and document sscanf() usage
selftests/x86: Fix vDSO selftest segfault for vsyscall=none
x86/entry/64: Remove the unused 'icebp' macro
...
Diffstat (limited to 'arch/x86/entry/entry_64.S')
-rw-r--r-- | arch/x86/entry/entry_64.S | 92 |
1 files changed, 19 insertions, 73 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 30c8c5344c4a..8971bd64d515 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -213,7 +213,7 @@ ENTRY(entry_SYSCALL_64) swapgs /* - * This path is not taken when PAGE_TABLE_ISOLATION is disabled so it + * This path is only taken when PAGE_TABLE_ISOLATION is disabled so it * is not required to switch CR3. */ movq %rsp, PER_CPU_VAR(rsp_scratch) @@ -227,22 +227,8 @@ ENTRY(entry_SYSCALL_64) pushq %rcx /* pt_regs->ip */ GLOBAL(entry_SYSCALL_64_after_hwframe) pushq %rax /* pt_regs->orig_ax */ - pushq %rdi /* pt_regs->di */ - pushq %rsi /* pt_regs->si */ - pushq %rdx /* pt_regs->dx */ - pushq %rcx /* pt_regs->cx */ - pushq $-ENOSYS /* pt_regs->ax */ - pushq %r8 /* pt_regs->r8 */ - pushq %r9 /* pt_regs->r9 */ - pushq %r10 /* pt_regs->r10 */ - pushq %r11 /* pt_regs->r11 */ - pushq %rbx /* pt_regs->rbx */ - pushq %rbp /* pt_regs->rbp */ - pushq %r12 /* pt_regs->r12 */ - pushq %r13 /* pt_regs->r13 */ - pushq %r14 /* pt_regs->r14 */ - pushq %r15 /* pt_regs->r15 */ - UNWIND_HINT_REGS + + PUSH_AND_CLEAR_REGS rax=$-ENOSYS TRACE_IRQS_OFF @@ -321,15 +307,7 @@ GLOBAL(entry_SYSCALL_64_after_hwframe) syscall_return_via_sysret: /* rcx and r11 are already restored (see code above) */ UNWIND_HINT_EMPTY - POP_EXTRA_REGS - popq %rsi /* skip r11 */ - popq %r10 - popq %r9 - popq %r8 - popq %rax - popq %rsi /* skip rcx */ - popq %rdx - popq %rsi + POP_REGS pop_rdi=0 skip_r11rcx=1 /* * Now all regs are restored except RSP and RDI. @@ -559,9 +537,7 @@ END(irq_entries_start) call switch_to_thread_stack 1: - ALLOC_PT_GPREGS_ON_STACK - SAVE_C_REGS - SAVE_EXTRA_REGS + PUSH_AND_CLEAR_REGS ENCODE_FRAME_POINTER testb $3, CS(%rsp) @@ -622,15 +598,7 @@ GLOBAL(swapgs_restore_regs_and_return_to_usermode) ud2 1: #endif - POP_EXTRA_REGS - popq %r11 - popq %r10 - popq %r9 - popq %r8 - popq %rax - popq %rcx - popq %rdx - popq %rsi + POP_REGS pop_rdi=0 /* * The stack is now user RDI, orig_ax, RIP, CS, EFLAGS, RSP, SS. @@ -688,8 +656,7 @@ GLOBAL(restore_regs_and_return_to_kernel) ud2 1: #endif - POP_EXTRA_REGS - POP_C_REGS + POP_REGS addq $8, %rsp /* skip regs->orig_ax */ /* * ARCH_HAS_MEMBARRIER_SYNC_CORE rely on IRET core serialization @@ -908,7 +875,9 @@ ENTRY(\sym) pushq $-1 /* ORIG_RAX: no syscall to restart */ .endif - ALLOC_PT_GPREGS_ON_STACK + /* Save all registers in pt_regs */ + PUSH_AND_CLEAR_REGS + ENCODE_FRAME_POINTER .if \paranoid < 2 testb $3, CS(%rsp) /* If coming from userspace, switch stacks */ @@ -1121,9 +1090,7 @@ ENTRY(xen_failsafe_callback) addq $0x30, %rsp UNWIND_HINT_IRET_REGS pushq $-1 /* orig_ax = -1 => not a system call */ - ALLOC_PT_GPREGS_ON_STACK - SAVE_C_REGS - SAVE_EXTRA_REGS + PUSH_AND_CLEAR_REGS ENCODE_FRAME_POINTER jmp error_exit END(xen_failsafe_callback) @@ -1163,16 +1130,13 @@ idtentry machine_check do_mce has_error_code=0 paranoid=1 #endif /* - * Save all registers in pt_regs, and switch gs if needed. + * Switch gs if needed. * Use slow, but surefire "are we in kernel?" check. * Return: ebx=0: need swapgs on exit, ebx=1: otherwise */ ENTRY(paranoid_entry) UNWIND_HINT_FUNC cld - SAVE_C_REGS 8 - SAVE_EXTRA_REGS 8 - ENCODE_FRAME_POINTER 8 movl $1, %ebx movl $MSR_GS_BASE, %ecx rdmsr @@ -1211,21 +1175,18 @@ ENTRY(paranoid_exit) jmp .Lparanoid_exit_restore .Lparanoid_exit_no_swapgs: TRACE_IRQS_IRETQ_DEBUG + RESTORE_CR3 scratch_reg=%rbx save_reg=%r14 .Lparanoid_exit_restore: jmp restore_regs_and_return_to_kernel END(paranoid_exit) /* - * Save all registers in pt_regs, and switch gs if needed. + * Switch gs if needed. * Return: EBX=0: came from user mode; EBX=1: otherwise */ ENTRY(error_entry) - UNWIND_HINT_FUNC + UNWIND_HINT_REGS offset=8 cld - SAVE_C_REGS 8 - SAVE_EXTRA_REGS 8 - ENCODE_FRAME_POINTER 8 - xorl %ebx, %ebx testb $3, CS+8(%rsp) jz .Lerror_kernelspace @@ -1406,22 +1367,7 @@ ENTRY(nmi) pushq 1*8(%rdx) /* pt_regs->rip */ UNWIND_HINT_IRET_REGS pushq $-1 /* pt_regs->orig_ax */ - pushq %rdi /* pt_regs->di */ - pushq %rsi /* pt_regs->si */ - pushq (%rdx) /* pt_regs->dx */ - pushq %rcx /* pt_regs->cx */ - pushq %rax /* pt_regs->ax */ - pushq %r8 /* pt_regs->r8 */ - pushq %r9 /* pt_regs->r9 */ - pushq %r10 /* pt_regs->r10 */ - pushq %r11 /* pt_regs->r11 */ - pushq %rbx /* pt_regs->rbx */ - pushq %rbp /* pt_regs->rbp */ - pushq %r12 /* pt_regs->r12 */ - pushq %r13 /* pt_regs->r13 */ - pushq %r14 /* pt_regs->r14 */ - pushq %r15 /* pt_regs->r15 */ - UNWIND_HINT_REGS + PUSH_AND_CLEAR_REGS rdx=(%rdx) ENCODE_FRAME_POINTER /* @@ -1631,7 +1577,8 @@ end_repeat_nmi: * frame to point back to repeat_nmi. */ pushq $-1 /* ORIG_RAX: no syscall to restart */ - ALLOC_PT_GPREGS_ON_STACK + PUSH_AND_CLEAR_REGS + ENCODE_FRAME_POINTER /* * Use paranoid_entry to handle SWAPGS, but no need to use paranoid_exit @@ -1655,8 +1602,7 @@ end_repeat_nmi: nmi_swapgs: SWAPGS_UNSAFE_STACK nmi_restore: - POP_EXTRA_REGS - POP_C_REGS + POP_REGS /* * Skip orig_ax and the "outermost" frame to point RSP at the "iret" |