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-rw-r--r--arch/x86/entry/calling.h38
-rw-r--r--arch/x86/entry/common.c30
-rw-r--r--arch/x86/entry/entry_32.S237
-rw-r--r--arch/x86/entry/entry_64.S228
-rw-r--r--arch/x86/entry/syscall_64.c25
-rw-r--r--arch/x86/entry/syscalls/syscall_32.tbl6
-rw-r--r--arch/x86/entry/syscalls/syscall_64.tbl2
-rw-r--r--arch/x86/entry/syscalls/syscalltbl.sh35
-rw-r--r--arch/x86/entry/thunk_32.S2
-rw-r--r--arch/x86/entry/thunk_64.S9
-rw-r--r--arch/x86/entry/vdso/Makefile23
-rw-r--r--arch/x86/entry/vdso/vclock_gettime.c256
-rw-r--r--arch/x86/entry/vdso/vdso.lds.S2
-rw-r--r--arch/x86/entry/vdso/vdso32-setup.c7
-rw-r--r--arch/x86/entry/vdso/vdso32/vdso32.lds.S2
-rw-r--r--arch/x86/entry/vdso/vdsox32.lds.S1
-rw-r--r--arch/x86/entry/vdso/vma.c4
-rw-r--r--arch/x86/entry/vsyscall/Makefile2
-rw-r--r--arch/x86/entry/vsyscall/vsyscall_64.c41
-rw-r--r--arch/x86/entry/vsyscall/vsyscall_gtod.c83
20 files changed, 508 insertions, 525 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h
index efb0d1b1f15f..515c0ceeb4a3 100644
--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -172,21 +172,6 @@ For 32-bit we have the following conventions - kernel is built with
.endif
.endm
-/*
- * This is a sneaky trick to help the unwinder find pt_regs on the stack. The
- * frame pointer is replaced with an encoded pointer to pt_regs. The encoding
- * is just setting the LSB, which makes it an invalid stack address and is also
- * a signal to the unwinder that it's a pt_regs pointer in disguise.
- *
- * NOTE: This macro must be used *after* PUSH_AND_CLEAR_REGS because it corrupts
- * the original rbp.
- */
-.macro ENCODE_FRAME_POINTER ptregs_offset=0
-#ifdef CONFIG_FRAME_POINTER
- leaq 1+\ptregs_offset(%rsp), %rbp
-#endif
-.endm
-
#ifdef CONFIG_PAGE_TABLE_ISOLATION
/*
@@ -329,6 +314,23 @@ For 32-bit we have the following conventions - kernel is built with
#endif
+/*
+ * 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
+
.macro STACKLEAK_ERASE_NOCLOBBER
#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
PUSH_AND_CLEAR_REGS
@@ -358,3 +360,9 @@ 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/common.c b/arch/x86/entry/common.c
index 2418804e66b4..3f8e22615812 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -72,23 +72,18 @@ static long syscall_trace_enter(struct pt_regs *regs)
struct thread_info *ti = current_thread_info();
unsigned long ret = 0;
- bool emulated = false;
u32 work;
if (IS_ENABLED(CONFIG_DEBUG_ENTRY))
BUG_ON(regs != task_pt_regs(current));
- work = READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY;
+ work = READ_ONCE(ti->flags);
- if (unlikely(work & _TIF_SYSCALL_EMU))
- emulated = true;
-
- if ((emulated || (work & _TIF_SYSCALL_TRACE)) &&
- tracehook_report_syscall_entry(regs))
- return -1L;
-
- if (emulated)
- return -1L;
+ if (work & (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU)) {
+ ret = tracehook_report_syscall_entry(regs);
+ if (ret || (work & _TIF_SYSCALL_EMU))
+ return -1L;
+ }
#ifdef CONFIG_SECCOMP
/*
@@ -290,15 +285,16 @@ __visible void do_syscall_64(unsigned long nr, struct pt_regs *regs)
if (READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY)
nr = syscall_trace_enter(regs);
- /*
- * NB: Native and x32 syscalls are dispatched from the same
- * table. The only functional difference is the x32 bit in
- * regs->orig_ax, which changes the behavior of some syscalls.
- */
- nr &= __SYSCALL_MASK;
if (likely(nr < NR_syscalls)) {
nr = array_index_nospec(nr, NR_syscalls);
regs->ax = sys_call_table[nr](regs);
+#ifdef CONFIG_X86_X32_ABI
+ } else if (likely((nr & __X32_SYSCALL_BIT) &&
+ (nr & ~__X32_SYSCALL_BIT) < X32_NR_syscalls)) {
+ nr = array_index_nospec(nr & ~__X32_SYSCALL_BIT,
+ X32_NR_syscalls);
+ regs->ax = x32_sys_call_table[nr](regs);
+#endif
}
syscall_return_slowpath(regs);
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 7b23431be5cb..f83ca5aa8b77 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -63,11 +63,10 @@
* enough to patch inline, increasing performance.
*/
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
# define preempt_stop(clobbers) DISABLE_INTERRUPTS(clobbers); TRACE_IRQS_OFF
#else
# define preempt_stop(clobbers)
-# define resume_kernel restore_all_kernel
#endif
.macro TRACE_IRQS_IRET
@@ -203,9 +202,104 @@
.Lend_\@:
.endm
-.macro SAVE_ALL pt_regs_ax=%eax switch_stacks=0
+#define CS_FROM_ENTRY_STACK (1 << 31)
+#define CS_FROM_USER_CR3 (1 << 30)
+#define CS_FROM_KERNEL (1 << 29)
+
+.macro FIXUP_FRAME
+ /*
+ * The high bits of the CS dword (__csh) are used for CS_FROM_*.
+ * Clear them in case hardware didn't do this for us.
+ */
+ andl $0x0000ffff, 3*4(%esp)
+
+#ifdef CONFIG_VM86
+ testl $X86_EFLAGS_VM, 4*4(%esp)
+ jnz .Lfrom_usermode_no_fixup_\@
+#endif
+ testl $SEGMENT_RPL_MASK, 3*4(%esp)
+ jnz .Lfrom_usermode_no_fixup_\@
+
+ orl $CS_FROM_KERNEL, 3*4(%esp)
+
+ /*
+ * When we're here from kernel mode; the (exception) stack looks like:
+ *
+ * 5*4(%esp) - <previous context>
+ * 4*4(%esp) - flags
+ * 3*4(%esp) - cs
+ * 2*4(%esp) - ip
+ * 1*4(%esp) - orig_eax
+ * 0*4(%esp) - gs / function
+ *
+ * Lets build a 5 entry IRET frame after that, such that struct pt_regs
+ * is complete and in particular regs->sp is correct. This gives us
+ * the original 5 enties as gap:
+ *
+ * 12*4(%esp) - <previous context>
+ * 11*4(%esp) - gap / flags
+ * 10*4(%esp) - gap / cs
+ * 9*4(%esp) - gap / ip
+ * 8*4(%esp) - gap / orig_eax
+ * 7*4(%esp) - gap / gs / function
+ * 6*4(%esp) - ss
+ * 5*4(%esp) - sp
+ * 4*4(%esp) - flags
+ * 3*4(%esp) - cs
+ * 2*4(%esp) - ip
+ * 1*4(%esp) - orig_eax
+ * 0*4(%esp) - gs / function
+ */
+
+ pushl %ss # ss
+ pushl %esp # sp (points at ss)
+ addl $6*4, (%esp) # point sp back at the previous context
+ pushl 6*4(%esp) # flags
+ pushl 6*4(%esp) # cs
+ pushl 6*4(%esp) # ip
+ pushl 6*4(%esp) # orig_eax
+ pushl 6*4(%esp) # gs / function
+.Lfrom_usermode_no_fixup_\@:
+.endm
+
+.macro IRET_FRAME
+ testl $CS_FROM_KERNEL, 1*4(%esp)
+ jz .Lfinished_frame_\@
+
+ /*
+ * Reconstruct the 3 entry IRET frame right after the (modified)
+ * regs->sp without lowering %esp in between, such that an NMI in the
+ * middle doesn't scribble our stack.
+ */
+ pushl %eax
+ pushl %ecx
+ movl 5*4(%esp), %eax # (modified) regs->sp
+
+ movl 4*4(%esp), %ecx # flags
+ movl %ecx, -4(%eax)
+
+ movl 3*4(%esp), %ecx # cs
+ andl $0x0000ffff, %ecx
+ movl %ecx, -8(%eax)
+
+ movl 2*4(%esp), %ecx # ip
+ movl %ecx, -12(%eax)
+
+ movl 1*4(%esp), %ecx # eax
+ movl %ecx, -16(%eax)
+
+ popl %ecx
+ lea -16(%eax), %esp
+ popl %eax
+.Lfinished_frame_\@:
+.endm
+
+.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
pushl %ds
@@ -221,13 +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
@@ -247,22 +341,6 @@
.Lend_\@:
.endm
-/*
- * This is a sneaky trick to help the unwinder find pt_regs on the stack. The
- * frame pointer is replaced with an encoded pointer to pt_regs. The encoding
- * is just clearing the MSB, which makes it an invalid stack address and is also
- * a signal to the unwinder that it's a pt_regs pointer in disguise.
- *
- * NOTE: This macro must be used *after* SAVE_ALL because it corrupts the
- * original rbp.
- */
-.macro ENCODE_FRAME_POINTER
-#ifdef CONFIG_FRAME_POINTER
- mov %esp, %ebp
- andl $0x7fffffff, %ebp
-#endif
-.endm
-
.macro RESTORE_INT_REGS
popl %ebx
popl %ecx
@@ -375,9 +453,6 @@
* switch to it before we do any copying.
*/
-#define CS_FROM_ENTRY_STACK (1 << 31)
-#define CS_FROM_USER_CR3 (1 << 30)
-
.macro SWITCH_TO_KERNEL_STACK
ALTERNATIVE "", "jmp .Lend_\@", X86_FEATURE_XENPV
@@ -391,13 +466,6 @@
* that register for the time this macro runs
*/
- /*
- * The high bits of the CS dword (__csh) are used for
- * CS_FROM_ENTRY_STACK and CS_FROM_USER_CR3. Clear them in case
- * hardware didn't do this for us.
- */
- andl $(0x0000ffff), PT_CS(%esp)
-
/* Are we on the entry stack? Bail out if not! */
movl PER_CPU_VAR(cpu_entry_area), %ecx
addl $CPU_ENTRY_AREA_entry_stack + SIZEOF_entry_stack, %ecx
@@ -755,7 +823,7 @@ ret_from_intr:
andl $SEGMENT_RPL_MASK, %eax
#endif
cmpl $USER_RPL, %eax
- jb resume_kernel # not returning to v8086 or userspace
+ jb restore_all_kernel # not returning to v8086 or userspace
ENTRY(resume_userspace)
DISABLE_INTERRUPTS(CLBR_ANY)
@@ -765,18 +833,6 @@ ENTRY(resume_userspace)
jmp restore_all
END(ret_from_exception)
-#ifdef CONFIG_PREEMPT
-ENTRY(resume_kernel)
- DISABLE_INTERRUPTS(CLBR_ANY)
- cmpl $0, PER_CPU_VAR(__preempt_count)
- jnz restore_all_kernel
- testl $X86_EFLAGS_IF, PT_EFLAGS(%esp) # interrupts off (exception path) ?
- jz restore_all_kernel
- call preempt_schedule_irq
- jmp restore_all_kernel
-END(resume_kernel)
-#endif
-
GLOBAL(__begin_SYSENTER_singlestep_region)
/*
* All code from here through __end_SYSENTER_singlestep_region is subject
@@ -1019,6 +1075,7 @@ restore_all:
/* Restore user state */
RESTORE_REGS pop=4 # skip orig_eax/error_code
.Lirq_return:
+ IRET_FRAME
/*
* ARCH_HAS_MEMBARRIER_SYNC_CORE rely on IRET core serialization
* when returning from IPI handler and when returning from
@@ -1027,6 +1084,15 @@ restore_all:
INTERRUPT_RETURN
restore_all_kernel:
+#ifdef CONFIG_PREEMPTION
+ DISABLE_INTERRUPTS(CLBR_ANY)
+ cmpl $0, PER_CPU_VAR(__preempt_count)
+ jnz .Lno_preempt
+ testl $X86_EFLAGS_IF, PT_EFLAGS(%esp) # interrupts off (exception path) ?
+ jz .Lno_preempt
+ call preempt_schedule_irq
+.Lno_preempt:
+#endif
TRACE_IRQS_IRET
PARANOID_EXIT_TO_KERNEL_MODE
BUG_IF_WRONG_CR3
@@ -1104,6 +1170,30 @@ ENTRY(irq_entries_start)
.endr
END(irq_entries_start)
+#ifdef CONFIG_X86_LOCAL_APIC
+ .align 8
+ENTRY(spurious_entries_start)
+ vector=FIRST_SYSTEM_VECTOR
+ .rept (NR_VECTORS - FIRST_SYSTEM_VECTOR)
+ pushl $(~vector+0x80) /* Note: always in signed byte range */
+ vector=vector+1
+ jmp common_spurious
+ .align 8
+ .endr
+END(spurious_entries_start)
+
+common_spurious:
+ ASM_CLAC
+ addl $-0x80, (%esp) /* Adjust vector into the [-256, -1] range */
+ SAVE_ALL switch_stacks=1
+ ENCODE_FRAME_POINTER
+ TRACE_IRQS_OFF
+ movl %esp, %eax
+ call smp_spurious_interrupt
+ jmp ret_from_intr
+ENDPROC(common_spurious)
+#endif
+
/*
* the CPU automatically disables interrupts when executing an IRQ vector,
* so IRQ-flags tracing has to follow that:
@@ -1274,7 +1364,7 @@ ENTRY(xen_hypervisor_callback)
ENTRY(xen_do_upcall)
1: mov %esp, %eax
call xen_evtchn_do_upcall
-#ifndef CONFIG_PREEMPT
+#ifndef CONFIG_PREEMPTION
call xen_maybe_preempt_hcall
#endif
jmp ret_from_intr
@@ -1354,37 +1444,50 @@ BUILD_INTERRUPT3(hv_stimer0_callback_vector, HYPERV_STIMER0_VECTOR,
ENTRY(page_fault)
ASM_CLAC
pushl $do_page_fault
- ALIGN
- jmp common_exception
+ jmp common_exception_read_cr2
END(page_fault)
-common_exception:
+common_exception_read_cr2:
/* the function address is in %gs's slot on the stack */
- 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_GS(%esp), %edi
+ 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_NOSPEC %edi
+ jmp ret_from_exception
+END(common_exception_read_cr2)
+
+common_exception:
+ /* the function address is in %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
+ movl PT_GS(%esp), %edi # get the function address
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
@@ -1497,7 +1600,7 @@ END(general_protection)
ENTRY(async_page_fault)
ASM_CLAC
pushl $do_async_page_fault
- jmp common_exception
+ jmp common_exception_read_cr2
END(async_page_fault)
#endif
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 11aa3b2afa4d..b7c3ea4cb19d 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -8,7 +8,7 @@
*
* entry.S contains the system-call and fault low-level handling routines.
*
- * Some of this is documented in Documentation/x86/entry_64.txt
+ * Some of this is documented in Documentation/x86/entry_64.rst
*
* A note on terminology:
* - iret frame: Architecture defined interrupt frame from SS to RIP
@@ -375,6 +375,18 @@ ENTRY(irq_entries_start)
.endr
END(irq_entries_start)
+ .align 8
+ENTRY(spurious_entries_start)
+ vector=FIRST_SYSTEM_VECTOR
+ .rept (NR_VECTORS - FIRST_SYSTEM_VECTOR)
+ UNWIND_HINT_IRET_REGS
+ pushq $(~vector+0x80) /* Note: always in signed byte range */
+ jmp common_spurious
+ .align 8
+ vector=vector+1
+ .endr
+END(spurious_entries_start)
+
.macro DEBUG_ENTRY_ASSERT_IRQS_OFF
#ifdef CONFIG_DEBUG_ENTRY
pushq %rax
@@ -507,7 +519,7 @@ ENTRY(interrupt_entry)
testb $3, CS-ORIG_RAX+8(%rsp)
jz 1f
SWAPGS
-
+ FENCE_SWAPGS_USER_ENTRY
/*
* Switch to the thread stack. The IRET frame and orig_ax are
* on the stack, as well as the return address. RDI..R12 are
@@ -537,8 +549,10 @@ ENTRY(interrupt_entry)
UNWIND_HINT_FUNC
movq (%rdi), %rdi
+ jmp 2f
1:
-
+ FENCE_SWAPGS_KERNEL_ENTRY
+2:
PUSH_AND_CLEAR_REGS save_ret=1
ENCODE_FRAME_POINTER 8
@@ -571,10 +585,20 @@ _ASM_NOKPROBE(interrupt_entry)
/* Interrupt entry/exit. */
- /*
- * The interrupt stubs push (~vector+0x80) onto the stack and
- * then jump to common_interrupt.
- */
+/*
+ * The interrupt stubs push (~vector+0x80) onto the stack and
+ * then jump to common_spurious/interrupt.
+ */
+common_spurious:
+ addq $-0x80, (%rsp) /* Adjust vector to [-256, -1] range */
+ call interrupt_entry
+ UNWIND_HINT_REGS indirect=1
+ call smp_spurious_interrupt /* rdi points to pt_regs */
+ jmp ret_from_intr
+END(common_spurious)
+_ASM_NOKPROBE(common_spurious)
+
+/* common_interrupt is a hotpath. Align it */
.p2align CONFIG_X86_L1_CACHE_SHIFT
common_interrupt:
addq $-0x80, (%rsp) /* Adjust vector to [-256, -1] range */
@@ -640,7 +664,7 @@ GLOBAL(swapgs_restore_regs_and_return_to_usermode)
/* Returning to kernel space */
retint_kernel:
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
/* Interrupts are off */
/* Check if we need preemption */
btl $9, EFLAGS(%rsp) /* were interrupts off? */
@@ -842,18 +866,84 @@ 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
@@ -878,15 +968,19 @@ 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
@@ -912,47 +1006,7 @@ 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
/*
@@ -961,21 +1015,9 @@ 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
@@ -985,7 +1027,7 @@ 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
@@ -1016,10 +1058,10 @@ ENTRY(native_load_gs_index)
ENDPROC(native_load_gs_index)
EXPORT_SYMBOL(native_load_gs_index)
- _ASM_EXTABLE(.Lgs_change, bad_gs)
+ _ASM_EXTABLE(.Lgs_change, .Lbad_gs)
.section .fixup, "ax"
/* running with kernelgs */
-bad_gs:
+.Lbad_gs:
SWAPGS /* switch back to user gs */
.macro ZAP_GS
/* This can't be a string because the preprocessor needs to see it. */
@@ -1073,7 +1115,7 @@ ENTRY(xen_do_hypervisor_callback) /* do_hypervisor_callback(struct *pt_regs) */
call xen_evtchn_do_upcall
LEAVE_IRQ_STACK
-#ifndef CONFIG_PREEMPT
+#ifndef CONFIG_PREEMPTION
call xen_maybe_preempt_hcall
#endif
jmp error_exit
@@ -1142,6 +1184,11 @@ apicinterrupt3 HYPERV_STIMER0_VECTOR \
hv_stimer0_callback_vector hv_stimer0_vector_handler
#endif /* CONFIG_HYPERV */
+#if IS_ENABLED(CONFIG_ACRN_GUEST)
+apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
+ acrn_hv_callback_vector acrn_hv_vector_handler
+#endif
+
idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=IST_INDEX_DB ist_offset=DB_STACK_OFFSET
idtentry int3 do_int3 has_error_code=0 create_gap=1
idtentry stack_segment do_stack_segment has_error_code=1
@@ -1149,14 +1196,13 @@ idtentry stack_segment do_stack_segment has_error_code=1
#ifdef CONFIG_XEN_PV
idtentry xennmi do_nmi has_error_code=0
idtentry xendebug do_debug has_error_code=0
-idtentry xenint3 do_int3 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
@@ -1194,6 +1240,13 @@ ENTRY(paranoid_entry)
*/
SAVE_AND_SWITCH_TO_KERNEL_CR3 scratch_reg=%rax save_reg=%r14
+ /*
+ * The above SAVE_AND_SWITCH_TO_KERNEL_CR3 macro 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)
@@ -1244,6 +1297,7 @@ ENTRY(error_entry)
* from user mode due to an IRET fault.
*/
SWAPGS
+ FENCE_SWAPGS_USER_ENTRY
/* We have user CR3. Change to kernel CR3. */
SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
@@ -1255,18 +1309,11 @@ 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_lfence:
+ FENCE_SWAPGS_KERNEL_ENTRY
.Lerror_entry_done:
- TRACE_IRQS_OFF
ret
/*
@@ -1283,7 +1330,7 @@ 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
@@ -1291,6 +1338,7 @@ ENTRY(error_entry)
* .Lgs_change's error handler with kernel gsbase.
*/
SWAPGS
+ FENCE_SWAPGS_USER_ENTRY
SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
jmp .Lerror_entry_done
@@ -1305,6 +1353,7 @@ ENTRY(error_entry)
* gsbase and CR3. Switch to kernel gsbase and CR3:
*/
SWAPGS
+ FENCE_SWAPGS_USER_ENTRY
SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
/*
@@ -1396,6 +1445,7 @@ ENTRY(nmi)
swapgs
cld
+ FENCE_SWAPGS_USER_ENTRY
SWITCH_TO_KERNEL_CR3 scratch_reg=%rdx
movq %rsp, %rdx
movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp
@@ -1670,11 +1720,17 @@ nmi_restore:
iretq
END(nmi)
+#ifndef CONFIG_IA32_EMULATION
+/*
+ * This handles SYSCALL from 32-bit code. There is no way to program
+ * MSRs to fully disable 32-bit SYSCALL.
+ */
ENTRY(ignore_sysret)
UNWIND_HINT_EMPTY
mov $-ENOSYS, %eax
sysret
END(ignore_sysret)
+#endif
ENTRY(rewind_stack_do_exit)
UNWIND_HINT_FUNC
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index d5252bc1e380..b1bf31713374 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -10,10 +10,13 @@
/* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */
extern asmlinkage long sys_ni_syscall(const struct pt_regs *);
#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *);
+#define __SYSCALL_X32(nr, sym, qual) __SYSCALL_64(nr, sym, qual)
#include <asm/syscalls_64.h>
#undef __SYSCALL_64
+#undef __SYSCALL_X32
#define __SYSCALL_64(nr, sym, qual) [nr] = sym,
+#define __SYSCALL_X32(nr, sym, qual)
asmlinkage const sys_call_ptr_t sys_call_table[__NR_syscall_max+1] = {
/*
@@ -23,3 +26,25 @@ asmlinkage const sys_call_ptr_t sys_call_table[__NR_syscall_max+1] = {
[0 ... __NR_syscall_max] = &sys_ni_syscall,
#include <asm/syscalls_64.h>
};
+
+#undef __SYSCALL_64
+#undef __SYSCALL_X32
+
+#ifdef CONFIG_X86_X32_ABI
+
+#define __SYSCALL_64(nr, sym, qual)
+#define __SYSCALL_X32(nr, sym, qual) [nr] = sym,
+
+asmlinkage const sys_call_ptr_t x32_sys_call_table[__NR_syscall_x32_max+1] = {
+ /*
+ * Smells like a compiler bug -- it doesn't work
+ * when the & below is removed.
+ */
+ [0 ... __NR_syscall_x32_max] = &sys_ni_syscall,
+#include <asm/syscalls_64.h>
+};
+
+#undef __SYSCALL_64
+#undef __SYSCALL_X32
+
+#endif
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index ad968b7bac72..3fe02546aed3 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -186,11 +186,11 @@
172 i386 prctl sys_prctl __ia32_sys_prctl
173 i386 rt_sigreturn sys_rt_sigreturn sys32_rt_sigreturn
174 i386 rt_sigaction sys_rt_sigaction __ia32_compat_sys_rt_sigaction
-175 i386 rt_sigprocmask sys_rt_sigprocmask __ia32_sys_rt_sigprocmask
+175 i386 rt_sigprocmask sys_rt_sigprocmask __ia32_compat_sys_rt_sigprocmask
176 i386 rt_sigpending sys_rt_sigpending __ia32_compat_sys_rt_sigpending
177 i386 rt_sigtimedwait sys_rt_sigtimedwait_time32 __ia32_compat_sys_rt_sigtimedwait_time32
178 i386 rt_sigqueueinfo sys_rt_sigqueueinfo __ia32_compat_sys_rt_sigqueueinfo
-179 i386 rt_sigsuspend sys_rt_sigsuspend __ia32_sys_rt_sigsuspend
+179 i386 rt_sigsuspend sys_rt_sigsuspend __ia32_compat_sys_rt_sigsuspend
180 i386 pread64 sys_pread64 __ia32_compat_sys_x86_pread
181 i386 pwrite64 sys_pwrite64 __ia32_compat_sys_x86_pwrite
182 i386 chown sys_chown16 __ia32_sys_chown16
@@ -438,3 +438,5 @@
431 i386 fsconfig sys_fsconfig __ia32_sys_fsconfig
432 i386 fsmount sys_fsmount __ia32_sys_fsmount
433 i386 fspick sys_fspick __ia32_sys_fspick
+434 i386 pidfd_open sys_pidfd_open __ia32_sys_pidfd_open
+435 i386 clone3 sys_clone3 __ia32_sys_clone3
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index b4e6f9e6204a..c29976eca4a8 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -355,6 +355,8 @@
431 common fsconfig __x64_sys_fsconfig
432 common fsmount __x64_sys_fsmount
433 common fspick __x64_sys_fspick
+434 common pidfd_open __x64_sys_pidfd_open
+435 common clone3 __x64_sys_clone3/ptregs
#
# x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/arch/x86/entry/syscalls/syscalltbl.sh b/arch/x86/entry/syscalls/syscalltbl.sh
index 94fcd1951aca..1af2be39e7d9 100644
--- a/arch/x86/entry/syscalls/syscalltbl.sh
+++ b/arch/x86/entry/syscalls/syscalltbl.sh
@@ -1,13 +1,13 @@
-#!/bin/sh
+#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
in="$1"
out="$2"
syscall_macro() {
- abi="$1"
- nr="$2"
- entry="$3"
+ local abi="$1"
+ local nr="$2"
+ local entry="$3"
# Entry can be either just a function name or "function/qualifier"
real_entry="${entry%%/*}"
@@ -21,14 +21,14 @@ syscall_macro() {
}
emit() {
- abi="$1"
- nr="$2"
- entry="$3"
- compat="$4"
- umlentry=""
+ local abi="$1"
+ local nr="$2"
+ local entry="$3"
+ local compat="$4"
+ local umlentry=""
- if [ "$abi" = "64" -a -n "$compat" ]; then
- echo "a compat entry for a 64-bit syscall makes no sense" >&2
+ if [ "$abi" != "I386" -a -n "$compat" ]; then
+ echo "a compat entry ($abi: $compat) for a 64-bit syscall makes no sense" >&2
exit 1
fi
@@ -62,14 +62,17 @@ grep '^[0-9]' "$in" | sort -n | (
while read nr abi name entry compat; do
abi=`echo "$abi" | tr '[a-z]' '[A-Z]'`
if [ "$abi" = "COMMON" -o "$abi" = "64" ]; then
- # COMMON is the same as 64, except that we don't expect X32
- # programs to use it. Our expectation has nothing to do with
- # any generated code, so treat them the same.
emit 64 "$nr" "$entry" "$compat"
+ if [ "$abi" = "COMMON" ]; then
+ # COMMON means that this syscall exists in the same form for
+ # 64-bit and X32.
+ echo "#ifdef CONFIG_X86_X32_ABI"
+ emit X32 "$nr" "$entry" "$compat"
+ echo "#endif"
+ fi
elif [ "$abi" = "X32" ]; then
- # X32 is equivalent to 64 on an X32-compatible kernel.
echo "#ifdef CONFIG_X86_X32_ABI"
- emit 64 "$nr" "$entry" "$compat"
+ emit X32 "$nr" "$entry" "$compat"
echo "#endif"
elif [ "$abi" = "I386" ]; then
emit "$abi" "$nr" "$entry" "$compat"
diff --git a/arch/x86/entry/thunk_32.S b/arch/x86/entry/thunk_32.S
index cb3464525b37..2713490611a3 100644
--- a/arch/x86/entry/thunk_32.S
+++ b/arch/x86/entry/thunk_32.S
@@ -34,7 +34,7 @@
THUNK trace_hardirqs_off_thunk,trace_hardirqs_off_caller,1
#endif
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
THUNK ___preempt_schedule, preempt_schedule
THUNK ___preempt_schedule_notrace, preempt_schedule_notrace
EXPORT_SYMBOL(___preempt_schedule)
diff --git a/arch/x86/entry/thunk_64.S b/arch/x86/entry/thunk_64.S
index cfdca8b42c70..ea5c4167086c 100644
--- a/arch/x86/entry/thunk_64.S
+++ b/arch/x86/entry/thunk_64.S
@@ -12,9 +12,7 @@
/* rdi: arg1 ... normal C conventions. rax is saved/restored. */
.macro THUNK name, func, put_ret_addr_in_rdi=0
- .globl \name
- .type \name, @function
-\name:
+ ENTRY(\name)
pushq %rbp
movq %rsp, %rbp
@@ -35,6 +33,7 @@
call \func
jmp .L_restore
+ ENDPROC(\name)
_ASM_NOKPROBE(\name)
.endm
@@ -47,7 +46,7 @@
THUNK lockdep_sys_exit_thunk,lockdep_sys_exit
#endif
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
THUNK ___preempt_schedule, preempt_schedule
THUNK ___preempt_schedule_notrace, preempt_schedule_notrace
EXPORT_SYMBOL(___preempt_schedule)
@@ -56,7 +55,7 @@
#if defined(CONFIG_TRACE_IRQFLAGS) \
|| defined(CONFIG_DEBUG_LOCK_ALLOC) \
- || defined(CONFIG_PREEMPT)
+ || defined(CONFIG_PREEMPTION)
.L_restore:
popq %r11
popq %r10
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 42fe42e82baf..0f2154106d01 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -3,6 +3,12 @@
# Building vDSO images for x86.
#
+# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
+# the inclusion of generic Makefile.
+ARCH_REL_TYPE_ABS := R_X86_64_JUMP_SLOT|R_X86_64_GLOB_DAT|R_X86_64_RELATIVE|
+ARCH_REL_TYPE_ABS += R_386_GLOB_DAT|R_386_JMP_SLOT|R_386_RELATIVE
+include $(srctree)/lib/vdso/Makefile
+
KBUILD_CFLAGS += $(DISABLE_LTO)
KASAN_SANITIZE := n
UBSAN_SANITIZE := n
@@ -50,7 +56,7 @@ VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \
-z max-page-size=4096
$(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
- $(call if_changed,vdso)
+ $(call if_changed,vdso_and_check)
HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
hostprogs-y += vdso2c
@@ -83,6 +89,7 @@ $(vobjs): KBUILD_CFLAGS := $(filter-out $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS
#
CFLAGS_REMOVE_vdso-note.o = -pg
CFLAGS_REMOVE_vclock_gettime.o = -pg
+CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg
CFLAGS_REMOVE_vgetcpu.o = -pg
CFLAGS_REMOVE_vvar.o = -pg
@@ -120,9 +127,9 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE
$(call if_changed,objcopy)
$(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE
- $(call if_changed,vdso)
+ $(call if_changed,vdso_and_check)
-CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
+CPPFLAGS_vdso32/vdso32.lds = $(CPPFLAGS_vdso.lds)
VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1
targets += vdso32/vdso32.lds
@@ -159,7 +166,7 @@ $(obj)/vdso32.so.dbg: FORCE \
$(obj)/vdso32/note.o \
$(obj)/vdso32/system_call.o \
$(obj)/vdso32/sigreturn.o
- $(call if_changed,vdso)
+ $(call if_changed,vdso_and_check)
#
# The DSO images are built using a special linker script.
@@ -170,11 +177,13 @@ quiet_cmd_vdso = VDSO $@
-T $(filter %.lds,$^) $(filter %.o,$^) && \
sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
-VDSO_LDFLAGS = -shared $(call ld-option, --hash-style=both) \
- $(call ld-option, --build-id) $(call ld-option, --eh-frame-hdr) \
- -Bsymbolic
+VDSO_LDFLAGS = -shared --hash-style=both --build-id \
+ $(call ld-option, --eh-frame-hdr) -Bsymbolic
GCOV_PROFILE := n
+quiet_cmd_vdso_and_check = VDSO $@
+ cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)
+
#
# Install the unstripped copies of vdso*.so. If our toolchain supports
# build-id, install .build-id links as well.
diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c
index 4aed41f638bb..d9ff616bb0f6 100644
--- a/arch/x86/entry/vdso/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vclock_gettime.c
@@ -1,251 +1,85 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * Copyright 2006 Andi Kleen, SUSE Labs.
- *
* Fast user context implementation of clock_gettime, gettimeofday, and time.
*
+ * Copyright 2006 Andi Kleen, SUSE Labs.
+ * Copyright 2019 ARM Limited
+ *
* 32 Bit compat layer by Stefani Seibold <stefani@seibold.net>
* sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany
- *
- * The code should have no internal unresolved relocations.
- * Check with readelf after changing.
*/
-
-#include <uapi/linux/time.h>
-#include <asm/vgtod.h>
-#include <asm/vvar.h>
-#include <asm/unistd.h>
-#include <asm/msr.h>
-#include <asm/pvclock.h>
-#include <asm/mshyperv.h>
-#include <linux/math64.h>
#include <linux/time.h>
#include <linux/kernel.h>
+#include <linux/types.h>
-#define gtod (&VVAR(vsyscall_gtod_data))
+#include "../../../../lib/vdso/gettimeofday.c"
-extern int __vdso_clock_gettime(clockid_t clock, struct timespec *ts);
-extern int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz);
+extern int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz);
extern time_t __vdso_time(time_t *t);
-#ifdef CONFIG_PARAVIRT_CLOCK
-extern u8 pvclock_page[PAGE_SIZE]
- __attribute__((visibility("hidden")));
-#endif
-
-#ifdef CONFIG_HYPERV_TSCPAGE
-extern u8 hvclock_page[PAGE_SIZE]
- __attribute__((visibility("hidden")));
-#endif
-
-#ifndef BUILD_VDSO32
-
-notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
+int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
{
- long ret;
- asm ("syscall" : "=a" (ret), "=m" (*ts) :
- "0" (__NR_clock_gettime), "D" (clock), "S" (ts) :
- "rcx", "r11");
- return ret;
+ return __cvdso_gettimeofday(tv, tz);
}
-#else
+int gettimeofday(struct __kernel_old_timeval *, struct timezone *)
+ __attribute__((weak, alias("__vdso_gettimeofday")));
-notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
+time_t __vdso_time(time_t *t)
{
- long ret;
-
- asm (
- "mov %%ebx, %%edx \n"
- "mov %[clock], %%ebx \n"
- "call __kernel_vsyscall \n"
- "mov %%edx, %%ebx \n"
- : "=a" (ret), "=m" (*ts)
- : "0" (__NR_clock_gettime), [clock] "g" (clock), "c" (ts)
- : "edx");
- return ret;
+ return __cvdso_time(t);
}
-#endif
+time_t time(time_t *t) __attribute__((weak, alias("__vdso_time")));
-#ifdef CONFIG_PARAVIRT_CLOCK
-static notrace const struct pvclock_vsyscall_time_info *get_pvti0(void)
-{
- return (const struct pvclock_vsyscall_time_info *)&pvclock_page;
-}
-static notrace u64 vread_pvclock(void)
-{
- const struct pvclock_vcpu_time_info *pvti = &get_pvti0()->pvti;
- u32 version;
- u64 ret;
-
- /*
- * Note: The kernel and hypervisor must guarantee that cpu ID
- * number maps 1:1 to per-CPU pvclock time info.
- *
- * Because the hypervisor is entirely unaware of guest userspace
- * preemption, it cannot guarantee that per-CPU pvclock time
- * info is updated if the underlying CPU changes or that that
- * version is increased whenever underlying CPU changes.
- *
- * On KVM, we are guaranteed that pvti updates for any vCPU are
- * atomic as seen by *all* vCPUs. This is an even stronger
- * guarantee than we get with a normal seqlock.
- *
- * On Xen, we don't appear to have that guarantee, but Xen still
- * supplies a valid seqlock using the version field.
- *
- * We only do pvclock vdso timing at all if
- * PVCLOCK_TSC_STABLE_BIT is set, and we interpret that bit to
- * mean that all vCPUs have matching pvti and that the TSC is
- * synced, so we can just look at vCPU 0's pvti.
- */
-
- do {
- version = pvclock_read_begin(pvti);
-
- if (unlikely(!(pvti->flags & PVCLOCK_TSC_STABLE_BIT)))
- return U64_MAX;
-
- ret = __pvclock_read_cycles(pvti, rdtsc_ordered());
- } while (pvclock_read_retry(pvti, version));
-
- return ret;
-}
-#endif
-#ifdef CONFIG_HYPERV_TSCPAGE
-static notrace u64 vread_hvclock(void)
-{
- const struct ms_hyperv_tsc_page *tsc_pg =
- (const struct ms_hyperv_tsc_page *)&hvclock_page;
+#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);
- return hv_read_tsc_page(tsc_pg);
-}
-#endif
-
-notrace static inline u64 vgetcyc(int mode)
+int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
{
- if (mode == VCLOCK_TSC)
- return (u64)rdtsc_ordered();
-
- /*
- * For any memory-mapped vclock type, we need to make sure that gcc
- * doesn't cleverly hoist a load before the mode check. Otherwise we
- * might end up touching the memory-mapped page even if the vclock in
- * question isn't enabled, which will segfault. Hence the barriers.
- */
-#ifdef CONFIG_PARAVIRT_CLOCK
- if (mode == VCLOCK_PVCLOCK) {
- barrier();
- return vread_pvclock();
- }
-#endif
-#ifdef CONFIG_HYPERV_TSCPAGE
- if (mode == VCLOCK_HVCLOCK) {
- barrier();
- return vread_hvclock();
- }
-#endif
- return U64_MAX;
+ return __cvdso_clock_gettime(clock, ts);
}
-notrace static int do_hres(clockid_t clk, struct timespec *ts)
-{
- struct vgtod_ts *base = &gtod->basetime[clk];
- u64 cycles, last, sec, ns;
- unsigned int seq;
-
- do {
- seq = gtod_read_begin(gtod);
- cycles = vgetcyc(gtod->vclock_mode);
- ns = base->nsec;
- last = gtod->cycle_last;
- if (unlikely((s64)cycles < 0))
- return vdso_fallback_gettime(clk, ts);
- if (cycles > last)
- ns += (cycles - last) * gtod->mult;
- ns >>= gtod->shift;
- sec = base->sec;
- } while (unlikely(gtod_read_retry(gtod, seq)));
-
- /*
- * Do this outside the loop: a race inside the loop could result
- * in __iter_div_u64_rem() being extremely slow.
- */
- ts->tv_sec = sec + __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
- ts->tv_nsec = ns;
-
- return 0;
-}
+int clock_gettime(clockid_t, struct __kernel_timespec *)
+ __attribute__((weak, alias("__vdso_clock_gettime")));
-notrace static void do_coarse(clockid_t clk, struct timespec *ts)
+int __vdso_clock_getres(clockid_t clock,
+ struct __kernel_timespec *res)
{
- struct vgtod_ts *base = &gtod->basetime[clk];
- unsigned int seq;
-
- do {
- seq = gtod_read_begin(gtod);
- ts->tv_sec = base->sec;
- ts->tv_nsec = base->nsec;
- } while (unlikely(gtod_read_retry(gtod, seq)));
+ return __cvdso_clock_getres(clock, res);
}
+int clock_getres(clockid_t, struct __kernel_timespec *)
+ __attribute__((weak, alias("__vdso_clock_getres")));
-notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
+#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)
{
- unsigned int msk;
-
- /* Sort out negative (CPU/FD) and invalid clocks */
- if (unlikely((unsigned int) clock >= MAX_CLOCKS))
- return vdso_fallback_gettime(clock, ts);
-
- /*
- * Convert the clockid to a bitmask and use it to check which
- * clocks are handled in the VDSO directly.
- */
- msk = 1U << clock;
- if (likely(msk & VGTOD_HRES)) {
- return do_hres(clock, ts);
- } else if (msk & VGTOD_COARSE) {
- do_coarse(clock, ts);
- return 0;
- }
- return vdso_fallback_gettime(clock, ts);
+ return __cvdso_clock_gettime32(clock, ts);
}
-int clock_gettime(clockid_t, struct timespec *)
+int clock_gettime(clockid_t, struct old_timespec32 *)
__attribute__((weak, alias("__vdso_clock_gettime")));
-notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
+int __vdso_clock_gettime64(clockid_t clock, struct __kernel_timespec *ts)
{
- if (likely(tv != NULL)) {
- struct timespec *ts = (struct timespec *) tv;
-
- do_hres(CLOCK_REALTIME, ts);
- tv->tv_usec /= 1000;
- }
- if (unlikely(tz != NULL)) {
- tz->tz_minuteswest = gtod->tz_minuteswest;
- tz->tz_dsttime = gtod->tz_dsttime;
- }
-
- return 0;
+ return __cvdso_clock_gettime(clock, ts);
}
-int gettimeofday(struct timeval *, struct timezone *)
- __attribute__((weak, alias("__vdso_gettimeofday")));
-/*
- * This will break when the xtime seconds get inaccurate, but that is
- * unlikely
- */
-notrace time_t __vdso_time(time_t *t)
-{
- /* This is atomic on x86 so we don't need any locks. */
- time_t result = READ_ONCE(gtod->basetime[CLOCK_REALTIME].sec);
+int clock_gettime64(clockid_t, struct __kernel_timespec *)
+ __attribute__((weak, alias("__vdso_clock_gettime64")));
- if (t)
- *t = result;
- return result;
+int __vdso_clock_getres(clockid_t clock, struct old_timespec32 *res)
+{
+ return __cvdso_clock_getres_time32(clock, res);
}
-time_t time(time_t *t)
- __attribute__((weak, alias("__vdso_time")));
+
+int clock_getres(clockid_t, struct old_timespec32 *)
+ __attribute__((weak, alias("__vdso_clock_getres")));
+#endif
diff --git a/arch/x86/entry/vdso/vdso.lds.S b/arch/x86/entry/vdso/vdso.lds.S
index d3a2dce4cfa9..36b644e16272 100644
--- a/arch/x86/entry/vdso/vdso.lds.S
+++ b/arch/x86/entry/vdso/vdso.lds.S
@@ -25,6 +25,8 @@ VERSION {
__vdso_getcpu;
time;
__vdso_time;
+ clock_getres;
+ __vdso_clock_getres;
local: *;
};
}
diff --git a/arch/x86/entry/vdso/vdso32-setup.c b/arch/x86/entry/vdso/vdso32-setup.c
index 42d4c89f990e..240626e7f55a 100644
--- a/arch/x86/entry/vdso/vdso32-setup.c
+++ b/arch/x86/entry/vdso/vdso32-setup.c
@@ -65,9 +65,6 @@ subsys_initcall(sysenter_setup);
/* Register vsyscall32 into the ABI table */
#include <linux/sysctl.h>
-static const int zero;
-static const int one = 1;
-
static struct ctl_table abi_table2[] = {
{
.procname = "vsyscall32",
@@ -75,8 +72,8 @@ static struct ctl_table abi_table2[] = {
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
- .extra1 = (int *)&zero,
- .extra2 = (int *)&one,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
},
{}
};
diff --git a/arch/x86/entry/vdso/vdso32/vdso32.lds.S b/arch/x86/entry/vdso/vdso32/vdso32.lds.S
index 422764a81d32..c7720995ab1a 100644
--- a/arch/x86/entry/vdso/vdso32/vdso32.lds.S
+++ b/arch/x86/entry/vdso/vdso32/vdso32.lds.S
@@ -26,6 +26,8 @@ VERSION
__vdso_clock_gettime;
__vdso_gettimeofday;
__vdso_time;
+ __vdso_clock_getres;
+ __vdso_clock_gettime64;
};
LINUX_2.5 {
diff --git a/arch/x86/entry/vdso/vdsox32.lds.S b/arch/x86/entry/vdso/vdsox32.lds.S
index 05cd1c5c4a15..16a8050a4fb6 100644
--- a/arch/x86/entry/vdso/vdsox32.lds.S
+++ b/arch/x86/entry/vdso/vdsox32.lds.S
@@ -21,6 +21,7 @@ VERSION {
__vdso_gettimeofday;
__vdso_getcpu;
__vdso_time;
+ __vdso_clock_getres;
local: *;
};
}
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 8db1f594e8b1..f5937742b290 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -22,7 +22,7 @@
#include <asm/page.h>
#include <asm/desc.h>
#include <asm/cpufeature.h>
-#include <asm/mshyperv.h>
+#include <clocksource/hyperv_timer.h>
#if defined(CONFIG_X86_64)
unsigned int __read_mostly vdso64_enabled = 1;
@@ -122,7 +122,7 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
if (tsc_pg && vclock_was_used(VCLOCK_HVCLOCK))
return vmf_insert_pfn(vma, vmf->address,
- vmalloc_to_pfn(tsc_pg));
+ virt_to_phys(tsc_pg) >> PAGE_SHIFT);
}
return VM_FAULT_SIGBUS;
diff --git a/arch/x86/entry/vsyscall/Makefile b/arch/x86/entry/vsyscall/Makefile
index 1ac4dd116c26..93c1b3e949a7 100644
--- a/arch/x86/entry/vsyscall/Makefile
+++ b/arch/x86/entry/vsyscall/Makefile
@@ -2,7 +2,5 @@
#
# Makefile for the x86 low level vsyscall code
#
-obj-y := vsyscall_gtod.o
-
obj-$(CONFIG_X86_VSYSCALL_EMULATION) += vsyscall_64.o vsyscall_emu_64.o
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index d9d81ad7a400..e7c596dea947 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -42,9 +42,11 @@
#define CREATE_TRACE_POINTS
#include "vsyscall_trace.h"
-static enum { EMULATE, NONE } vsyscall_mode =
+static enum { EMULATE, XONLY, NONE } vsyscall_mode __ro_after_init =
#ifdef CONFIG_LEGACY_VSYSCALL_NONE
NONE;
+#elif defined(CONFIG_LEGACY_VSYSCALL_XONLY)
+ XONLY;
#else
EMULATE;
#endif
@@ -54,6 +56,8 @@ static int __init vsyscall_setup(char *str)
if (str) {
if (!strcmp("emulate", str))
vsyscall_mode = EMULATE;
+ else if (!strcmp("xonly", str))
+ vsyscall_mode = XONLY;
else if (!strcmp("none", str))
vsyscall_mode = NONE;
else
@@ -106,14 +110,15 @@ static bool write_ok_or_segv(unsigned long ptr, size_t size)
thread->cr2 = ptr;
thread->trap_nr = X86_TRAP_PF;
- force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)ptr, current);
+ force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)ptr);
return false;
} else {
return true;
}
}
-bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
+bool emulate_vsyscall(unsigned long error_code,
+ struct pt_regs *regs, unsigned long address)
{
struct task_struct *tsk;
unsigned long caller;
@@ -122,6 +127,22 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
long ret;
unsigned long orig_dx;
+ /* Write faults or kernel-privilege faults never get fixed up. */
+ if ((error_code & (X86_PF_WRITE | X86_PF_USER)) != X86_PF_USER)
+ return false;
+
+ if (!(error_code & X86_PF_INSTR)) {
+ /* Failed vsyscall read */
+ if (vsyscall_mode == EMULATE)
+ return false;
+
+ /*
+ * User code tried and failed to read the vsyscall page.
+ */
+ warn_bad_vsyscall(KERN_INFO, regs, "vsyscall read attempt denied -- look up the vsyscall kernel parameter if you need a workaround");
+ return false;
+ }
+
/*
* No point in checking CS -- the only way to get here is a user mode
* trap to a high address, which means that we're in 64-bit user code.
@@ -268,7 +289,7 @@ do_ret:
return true;
sigsegv:
- force_sig(SIGSEGV, current);
+ force_sig(SIGSEGV);
return true;
}
@@ -284,7 +305,7 @@ static const char *gate_vma_name(struct vm_area_struct *vma)
static const struct vm_operations_struct gate_vma_ops = {
.name = gate_vma_name,
};
-static struct vm_area_struct gate_vma = {
+static struct vm_area_struct gate_vma __ro_after_init = {
.vm_start = VSYSCALL_ADDR,
.vm_end = VSYSCALL_ADDR + PAGE_SIZE,
.vm_page_prot = PAGE_READONLY_EXEC,
@@ -357,12 +378,20 @@ void __init map_vsyscall(void)
extern char __vsyscall_page;
unsigned long physaddr_vsyscall = __pa_symbol(&__vsyscall_page);
- if (vsyscall_mode != NONE) {
+ /*
+ * For full emulation, the page needs to exist for real. In
+ * execute-only mode, there is no PTE at all backing the vsyscall
+ * page.
+ */
+ if (vsyscall_mode == EMULATE) {
__set_fixmap(VSYSCALL_PAGE, physaddr_vsyscall,
PAGE_KERNEL_VVAR);
set_vsyscall_pgtable_user_bits(swapper_pg_dir);
}
+ if (vsyscall_mode == XONLY)
+ gate_vma.vm_flags = VM_EXEC;
+
BUILD_BUG_ON((unsigned long)__fix_to_virt(VSYSCALL_PAGE) !=
(unsigned long)VSYSCALL_ADDR);
}
diff --git a/arch/x86/entry/vsyscall/vsyscall_gtod.c b/arch/x86/entry/vsyscall/vsyscall_gtod.c
deleted file mode 100644
index cfcdba082feb..000000000000
--- a/arch/x86/entry/vsyscall/vsyscall_gtod.c
+++ /dev/null
@@ -1,83 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
- * Copyright 2003 Andi Kleen, SuSE Labs.
- *
- * Modified for x86 32 bit architecture by
- * Stefani Seibold <stefani@seibold.net>
- * sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany
- *
- * Thanks to hpa@transmeta.com for some useful hint.
- * Special thanks to Ingo Molnar for his early experience with
- * a different vsyscall implementation for Linux/IA32 and for the name.
- *
- */
-
-#include <linux/timekeeper_internal.h>
-#include <asm/vgtod.h>
-#include <asm/vvar.h>
-
-int vclocks_used __read_mostly;
-
-DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data);
-
-void update_vsyscall_tz(void)
-{
- vsyscall_gtod_data.tz_minuteswest = sys_tz.tz_minuteswest;
- vsyscall_gtod_data.tz_dsttime = sys_tz.tz_dsttime;
-}
-
-void update_vsyscall(struct timekeeper *tk)
-{
- int vclock_mode = tk->tkr_mono.clock->archdata.vclock_mode;
- struct vsyscall_gtod_data *vdata = &vsyscall_gtod_data;
- struct vgtod_ts *base;
- u64 nsec;
-
- /* Mark the new vclock used. */
- BUILD_BUG_ON(VCLOCK_MAX >= 32);
- WRITE_ONCE(vclocks_used, READ_ONCE(vclocks_used) | (1 << vclock_mode));
-
- gtod_write_begin(vdata);
-
- /* copy vsyscall data */
- vdata->vclock_mode = vclock_mode;
- vdata->cycle_last = tk->tkr_mono.cycle_last;
- vdata->mask = tk->tkr_mono.mask;
- vdata->mult = tk->tkr_mono.mult;
- vdata->shift = tk->tkr_mono.shift;
-
- base = &vdata->basetime[CLOCK_REALTIME];
- base->sec = tk->xtime_sec;
- base->nsec = tk->tkr_mono.xtime_nsec;
-
- base = &vdata->basetime[CLOCK_TAI];
- base->sec = tk->xtime_sec + (s64)tk->tai_offset;
- base->nsec = tk->tkr_mono.xtime_nsec;
-
- base = &vdata->basetime[CLOCK_MONOTONIC];
- base->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
- nsec = tk->tkr_mono.xtime_nsec;
- nsec += ((u64)tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift);
- while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
- nsec -= ((u64)NSEC_PER_SEC) << tk->tkr_mono.shift;
- base->sec++;
- }
- base->nsec = nsec;
-
- base = &vdata->basetime[CLOCK_REALTIME_COARSE];
- base->sec = tk->xtime_sec;
- base->nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
-
- base = &vdata->basetime[CLOCK_MONOTONIC_COARSE];
- base->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
- nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
- nsec += tk->wall_to_monotonic.tv_nsec;
- while (nsec >= NSEC_PER_SEC) {
- nsec -= NSEC_PER_SEC;
- base->sec++;
- }
- base->nsec = nsec;
-
- gtod_write_end(vdata);
-}
generated by cgit v1.2.3 (git 2.39.0) at 2024-10-14 01:26:54 +0300