diff options
Diffstat (limited to 'arch/x86/entry')
| -rw-r--r-- | arch/x86/entry/calling.h | 12 | ||||
| -rw-r--r-- | arch/x86/entry/entry.S | 23 | ||||
| -rw-r--r-- | arch/x86/entry/entry_32.S | 3 | ||||
| -rw-r--r-- | arch/x86/entry/entry_64.S | 44 | ||||
| -rw-r--r-- | arch/x86/entry/entry_64_compat.S | 1 | ||||
| -rw-r--r-- | arch/x86/entry/syscalls/syscall_32.tbl | 5 | ||||
| -rw-r--r-- | arch/x86/entry/syscalls/syscall_64.tbl | 5 | ||||
| -rw-r--r-- | arch/x86/entry/vdso/vclock_gettime.c | 10 |
8 files changed, 80 insertions, 23 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index f6907627172b..9f1d94790a54 100644 --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -175,8 +175,7 @@ For 32-bit we have the following conventions - kernel is built with #define THIS_CPU_user_pcid_flush_mask \ PER_CPU_VAR(cpu_tlbstate) + TLB_STATE_user_pcid_flush_mask -.macro SWITCH_TO_USER_CR3_NOSTACK scratch_reg:req scratch_reg2:req - ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI +.macro SWITCH_TO_USER_CR3 scratch_reg:req scratch_reg2:req mov %cr3, \scratch_reg ALTERNATIVE "jmp .Lwrcr3_\@", "", X86_FEATURE_PCID @@ -206,13 +205,20 @@ For 32-bit we have the following conventions - kernel is built with /* Flip the PGD to the user version */ orq $(PTI_USER_PGTABLE_MASK), \scratch_reg mov \scratch_reg, %cr3 +.endm + +.macro SWITCH_TO_USER_CR3_NOSTACK scratch_reg:req scratch_reg2:req + ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI + SWITCH_TO_USER_CR3 \scratch_reg \scratch_reg2 .Lend_\@: .endm .macro SWITCH_TO_USER_CR3_STACK scratch_reg:req + ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI pushq %rax - SWITCH_TO_USER_CR3_NOSTACK scratch_reg=\scratch_reg scratch_reg2=%rax + SWITCH_TO_USER_CR3 scratch_reg=\scratch_reg scratch_reg2=%rax popq %rax +.Lend_\@: .endm .macro SAVE_AND_SWITCH_TO_KERNEL_CR3 scratch_reg:req save_reg:req diff --git a/arch/x86/entry/entry.S b/arch/x86/entry/entry.S index 8c8d38f0cb1d..003379049924 100644 --- a/arch/x86/entry/entry.S +++ b/arch/x86/entry/entry.S @@ -6,6 +6,9 @@ #include <linux/export.h> #include <linux/linkage.h> #include <asm/msr-index.h> +#include <asm/unwind_hints.h> +#include <asm/segment.h> +#include <asm/cache.h> .pushsection .noinstr.text, "ax" @@ -20,3 +23,23 @@ SYM_FUNC_END(entry_ibpb) EXPORT_SYMBOL_GPL(entry_ibpb); .popsection + +/* + * Define the VERW operand that is disguised as entry code so that + * it can be referenced with KPTI enabled. This ensure VERW can be + * used late in exit-to-user path after page tables are switched. + */ +.pushsection .entry.text, "ax" + +.align L1_CACHE_BYTES, 0xcc +SYM_CODE_START_NOALIGN(mds_verw_sel) + UNWIND_HINT_UNDEFINED + ANNOTATE_NOENDBR + .word __KERNEL_DS +.align L1_CACHE_BYTES, 0xcc +SYM_CODE_END(mds_verw_sel); +/* For KVM */ +EXPORT_SYMBOL_GPL(mds_verw_sel); + +.popsection + diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index c73047bf9f4b..fba427646805 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -885,6 +885,7 @@ SYM_FUNC_START(entry_SYSENTER_32) BUG_IF_WRONG_CR3 no_user_check=1 popfl popl %eax + CLEAR_CPU_BUFFERS /* * Return back to the vDSO, which will pop ecx and edx. @@ -954,6 +955,7 @@ 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 @@ -1146,6 +1148,7 @@ SYM_CODE_START(asm_exc_nmi) /* Not on SYSENTER stack. */ call exc_nmi + CLEAR_CPU_BUFFERS jmp .Lnmi_return .Lnmi_from_sysenter_stack: diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index de6469dffe3a..9bb485977629 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -161,6 +161,7 @@ syscall_return_via_sysret: SYM_INNER_LABEL(entry_SYSRETQ_unsafe_stack, SYM_L_GLOBAL) ANNOTATE_NOENDBR swapgs + CLEAR_CPU_BUFFERS sysretq SYM_INNER_LABEL(entry_SYSRETQ_end, SYM_L_GLOBAL) ANNOTATE_NOENDBR @@ -559,17 +560,28 @@ __irqentry_text_end: SYM_CODE_START_LOCAL(common_interrupt_return) SYM_INNER_LABEL(swapgs_restore_regs_and_return_to_usermode, SYM_L_GLOBAL) IBRS_EXIT -#ifdef CONFIG_DEBUG_ENTRY - /* Assert that pt_regs indicates user mode. */ - testb $3, CS(%rsp) - jnz 1f - ud2 -1: -#endif #ifdef CONFIG_XEN_PV ALTERNATIVE "", "jmp xenpv_restore_regs_and_return_to_usermode", X86_FEATURE_XENPV #endif +#ifdef CONFIG_PAGE_TABLE_ISOLATION + ALTERNATIVE "", "jmp .Lpti_restore_regs_and_return_to_usermode", X86_FEATURE_PTI +#endif + + STACKLEAK_ERASE + POP_REGS + add $8, %rsp /* orig_ax */ + UNWIND_HINT_IRET_REGS + +.Lswapgs_and_iret: + swapgs + CLEAR_CPU_BUFFERS + /* Assert that the IRET frame indicates user mode. */ + testb $3, 8(%rsp) + jnz .Lnative_iret + ud2 +#ifdef CONFIG_PAGE_TABLE_ISOLATION +.Lpti_restore_regs_and_return_to_usermode: POP_REGS pop_rdi=0 /* @@ -596,13 +608,14 @@ SYM_INNER_LABEL(swapgs_restore_regs_and_return_to_usermode, SYM_L_GLOBAL) */ STACKLEAK_ERASE_NOCLOBBER - SWITCH_TO_USER_CR3_STACK scratch_reg=%rdi + push %rax + SWITCH_TO_USER_CR3 scratch_reg=%rdi scratch_reg2=%rax + pop %rax /* Restore RDI. */ popq %rdi - swapgs - jmp .Lnative_iret - + jmp .Lswapgs_and_iret +#endif SYM_INNER_LABEL(restore_regs_and_return_to_kernel, SYM_L_GLOBAL) #ifdef CONFIG_DEBUG_ENTRY @@ -712,6 +725,8 @@ native_irq_return_ldt: */ popq %rax /* Restore user RAX */ + CLEAR_CPU_BUFFERS + /* * RSP now points to an ordinary IRET frame, except that the page * is read-only and RSP[31:16] are preloaded with the userspace @@ -1439,6 +1454,12 @@ nmi_restore: movq $0, 5*8(%rsp) /* clear "NMI executing" */ /* + * Skip CLEAR_CPU_BUFFERS here, since it only helps in rare cases like + * NMI in kernel after user state is restored. For an unprivileged user + * these conditions are hard to meet. + */ + + /* * iretq reads the "iret" frame and exits the NMI stack in a * single instruction. We are returning to kernel mode, so this * cannot result in a fault. Similarly, we don't need to worry @@ -1455,6 +1476,7 @@ SYM_CODE_START(entry_SYSCALL32_ignore) UNWIND_HINT_END_OF_STACK ENDBR mov $-ENOSYS, %eax + CLEAR_CPU_BUFFERS sysretl SYM_CODE_END(entry_SYSCALL32_ignore) diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index de94e2e84ecc..eabf48c4d4b4 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -270,6 +270,7 @@ SYM_INNER_LABEL(entry_SYSRETL_compat_unsafe_stack, SYM_L_GLOBAL) xorl %r9d, %r9d xorl %r10d, %r10d swapgs + CLEAR_CPU_BUFFERS sysretl SYM_INNER_LABEL(entry_SYSRETL_compat_end, SYM_L_GLOBAL) ANNOTATE_NOENDBR diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index c8fac5205803..5f8591ce7f25 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -461,3 +461,8 @@ 454 i386 futex_wake sys_futex_wake 455 i386 futex_wait sys_futex_wait 456 i386 futex_requeue sys_futex_requeue +457 i386 statmount sys_statmount +458 i386 listmount sys_listmount +459 i386 lsm_get_self_attr sys_lsm_get_self_attr +460 i386 lsm_set_self_attr sys_lsm_set_self_attr +461 i386 lsm_list_modules sys_lsm_list_modules diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 8cb8bf68721c..7e8d46f4147f 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -378,6 +378,11 @@ 454 common futex_wake sys_futex_wake 455 common futex_wait sys_futex_wait 456 common futex_requeue sys_futex_requeue +457 common statmount sys_statmount +458 common listmount sys_listmount +459 common lsm_get_self_attr sys_lsm_get_self_attr +460 common lsm_set_self_attr sys_lsm_set_self_attr +461 common lsm_list_modules sys_lsm_list_modules # # Due to a historical design error, certain syscalls are numbered differently diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c index 7d70935b6758..0debc194bd78 100644 --- a/arch/x86/entry/vdso/vclock_gettime.c +++ b/arch/x86/entry/vdso/vclock_gettime.c @@ -11,12 +11,10 @@ #include <linux/time.h> #include <linux/kernel.h> #include <linux/types.h> +#include <vdso/gettime.h> #include "../../../../lib/vdso/gettimeofday.c" -extern int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz); -extern __kernel_old_time_t __vdso_time(__kernel_old_time_t *t); - int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz) { return __cvdso_gettimeofday(tv, tz); @@ -35,9 +33,6 @@ __kernel_old_time_t time(__kernel_old_time_t *t) __attribute__((weak, alias("__v #if defined(CONFIG_X86_64) && !defined(BUILD_VDSO32_64) /* both 64-bit and x32 use these */ -extern int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts); -extern int __vdso_clock_getres(clockid_t clock, struct __kernel_timespec *res); - int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) { return __cvdso_clock_gettime(clock, ts); @@ -56,9 +51,6 @@ int clock_getres(clockid_t, struct __kernel_timespec *) #else /* i386 only */ -extern int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts); -extern int __vdso_clock_getres(clockid_t clock, struct old_timespec32 *res); - int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts) { return __cvdso_clock_gettime32(clock, ts); |