diff options
author | Otavio Salvador <otavio@ossystems.com.br> | 2020-05-20 08:43:03 -0300 |
---|---|---|
committer | GitHub <noreply@github.com> | 2020-05-20 08:43:03 -0300 |
commit | 1279cd128bba968ebe0a2df7f7ae38bae90250ef (patch) | |
tree | df6b1a190760f51465122ca4c13492d5ac5984c6 /arch/x86/entry | |
parent | 0a8ab17689e628c84a666195bfc6ab85d11cf057 (diff) | |
parent | 2ae782ca839e0ee07de37122ddea362adff2e975 (diff) |
Merge pull request #76 from toradex/4.9-2.3.x-imx
4.9 2.3.x imx
Diffstat (limited to 'arch/x86/entry')
-rw-r--r-- | arch/x86/entry/calling.h | 18 | ||||
-rw-r--r-- | arch/x86/entry/common.c | 3 | ||||
-rw-r--r-- | arch/x86/entry/entry_32.S | 3 | ||||
-rw-r--r-- | arch/x86/entry/entry_64.S | 23 | ||||
-rw-r--r-- | arch/x86/entry/vdso/Makefile | 23 | ||||
-rw-r--r-- | arch/x86/entry/vdso/vdso32-setup.c | 1 |
6 files changed, 56 insertions, 15 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index 9a9e5884066c..8af8c070f213 100644 --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -1,4 +1,5 @@ #include <linux/jump_label.h> +#include <asm/cpufeatures.h> /* @@ -201,6 +202,23 @@ For 32-bit we have the following conventions - kernel is built with .byte 0xf1 .endm +/* + * Mitigate Spectre v1 for conditional swapgs code paths. + * + * FENCE_SWAPGS_USER_ENTRY is used in the user entry swapgs code path, to + * prevent a speculative swapgs when coming from kernel space. + * + * FENCE_SWAPGS_KERNEL_ENTRY is used in the kernel entry non-swapgs code path, + * to prevent the swapgs from getting speculatively skipped when coming from + * user space. + */ +.macro FENCE_SWAPGS_USER_ENTRY + ALTERNATIVE "", "lfence", X86_FEATURE_FENCE_SWAPGS_USER +.endm +.macro FENCE_SWAPGS_KERNEL_ENTRY + ALTERNATIVE "", "lfence", X86_FEATURE_FENCE_SWAPGS_KERNEL +.endm + #endif /* CONFIG_X86_64 */ /* diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index b0cd306dc527..8841d016b4a4 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -28,6 +28,7 @@ #include <asm/vdso.h> #include <asm/uaccess.h> #include <asm/cpufeature.h> +#include <asm/nospec-branch.h> #define CREATE_TRACE_POINTS #include <trace/events/syscalls.h> @@ -206,6 +207,8 @@ __visible inline void prepare_exit_to_usermode(struct pt_regs *regs) #endif user_enter_irqoff(); + + mds_user_clear_cpu_buffers(); } #define SYSCALL_EXIT_WORK_FLAGS \ diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index a76dc738ec61..4d980d11e2d1 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -219,6 +219,7 @@ ENTRY(__switch_to_asm) pushl %ebx pushl %edi pushl %esi + pushfl /* switch stack */ movl %esp, TASK_threadsp(%eax) @@ -241,6 +242,7 @@ ENTRY(__switch_to_asm) #endif /* restore callee-saved registers */ + popfl popl %esi popl %edi popl %ebx @@ -1193,6 +1195,7 @@ ENTRY(int3) END(int3) ENTRY(general_protection) + ASM_CLAC pushl $do_general_protection jmp error_code END(general_protection) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 870e941c1947..10ecfba43dff 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -313,6 +313,7 @@ ENTRY(__switch_to_asm) pushq %r13 pushq %r14 pushq %r15 + pushfq /* switch stack */ movq %rsp, TASK_threadsp(%rdi) @@ -335,6 +336,7 @@ ENTRY(__switch_to_asm) #endif /* restore callee-saved registers */ + popfq popq %r15 popq %r14 popq %r13 @@ -418,6 +420,7 @@ END(irq_entries_start) * tracking that we're in kernel mode. */ SWAPGS + FENCE_SWAPGS_USER_ENTRY SWITCH_KERNEL_CR3 /* @@ -431,8 +434,10 @@ END(irq_entries_start) TRACE_IRQS_OFF CALL_enter_from_user_mode - + jmp 2f 1: + FENCE_SWAPGS_KERNEL_ENTRY +2: /* * Save previous stack pointer, optionally switch to interrupt stack. * irq_count is used to check if a CPU is already on an interrupt stack @@ -1002,6 +1007,13 @@ ENTRY(paranoid_entry) movq %rax, %cr3 2: #endif + /* + * The above doesn't do an unconditional CR3 write, even in the PTI + * case. So do an lfence to prevent GS speculation, regardless of + * whether PTI is enabled. + */ + FENCE_SWAPGS_KERNEL_ENTRY + ret END(paranoid_entry) @@ -1063,6 +1075,7 @@ ENTRY(error_entry) * from user mode due to an IRET fault. */ SWAPGS + FENCE_SWAPGS_USER_ENTRY .Lerror_entry_from_usermode_after_swapgs: /* @@ -1074,6 +1087,8 @@ ENTRY(error_entry) CALL_enter_from_user_mode ret +.Lerror_entry_done_lfence: + FENCE_SWAPGS_KERNEL_ENTRY .Lerror_entry_done: TRACE_IRQS_OFF ret @@ -1092,7 +1107,7 @@ ENTRY(error_entry) cmpq %rax, RIP+8(%rsp) je .Lbstep_iret cmpq $.Lgs_change, RIP+8(%rsp) - jne .Lerror_entry_done + jne .Lerror_entry_done_lfence /* * hack: .Lgs_change can fail with user gsbase. If this happens, fix up @@ -1100,6 +1115,7 @@ ENTRY(error_entry) * .Lgs_change's error handler with kernel gsbase. */ SWAPGS + FENCE_SWAPGS_USER_ENTRY jmp .Lerror_entry_done .Lbstep_iret: @@ -1113,6 +1129,7 @@ ENTRY(error_entry) * Switch to kernel gsbase: */ SWAPGS + FENCE_SWAPGS_USER_ENTRY /* * Pretend that the exception came from user mode: set up pt_regs @@ -1209,6 +1226,7 @@ ENTRY(nmi) * to switch CR3 here. */ cld + FENCE_SWAPGS_USER_ENTRY movq %rsp, %rdx movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp pushq 5*8(%rdx) /* pt_regs->ss */ @@ -1497,6 +1515,7 @@ end_repeat_nmi: movq %rax, %cr3 2: #endif + FENCE_SWAPGS_KERNEL_ENTRY /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */ call do_nmi diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index d5409660f5de..0d3ebdfa0739 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -47,10 +47,8 @@ targets += $(vdso_img_sodbg) export CPPFLAGS_vdso.lds += -P -C -VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \ - -Wl,--no-undefined \ - -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \ - $(DISABLE_LTO) +VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \ + -z max-page-size=4096 $(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE $(call if_changed,vdso) @@ -96,10 +94,8 @@ CFLAGS_REMOVE_vvar.o = -pg # CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds) -VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \ - -Wl,-soname=linux-vdso.so.1 \ - -Wl,-z,max-page-size=4096 \ - -Wl,-z,common-page-size=4096 +VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \ + -z max-page-size=4096 # 64-bit objects to re-brand as x32 vobjs64-for-x32 := $(filter-out $(vobjs-nox32),$(vobjs-y)) @@ -127,7 +123,7 @@ $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE $(call if_changed,vdso) CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds) -VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1 +VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1 # This makes sure the $(obj) subdirectory exists even though vdso32/ # is not a kbuild sub-make subdirectory. @@ -165,13 +161,14 @@ $(obj)/vdso32.so.dbg: FORCE \ # The DSO images are built using a special linker script. # quiet_cmd_vdso = VDSO $@ - cmd_vdso = $(CC) -nostdlib -o $@ \ + cmd_vdso = $(LD) -nostdlib -o $@ \ $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \ - -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \ + -T $(filter %.lds,$^) $(filter %.o,$^) && \ sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@' -VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=both) \ - $(call cc-ldoption, -Wl$(comma)--build-id) -Wl,-Bsymbolic $(LTO_CFLAGS) +VDSO_LDFLAGS = -shared $(call ld-option, --hash-style=both) \ + $(call ld-option, --build-id) $(call ld-option, --eh-frame-hdr) \ + -Bsymbolic GCOV_PROFILE := n # diff --git a/arch/x86/entry/vdso/vdso32-setup.c b/arch/x86/entry/vdso/vdso32-setup.c index 3f9d1a83891a..50c1f77cab15 100644 --- a/arch/x86/entry/vdso/vdso32-setup.c +++ b/arch/x86/entry/vdso/vdso32-setup.c @@ -10,6 +10,7 @@ #include <linux/smp.h> #include <linux/kernel.h> #include <linux/mm_types.h> +#include <linux/elf.h> #include <asm/processor.h> #include <asm/vdso.h> |