Merge remote-tracking branch 'drm/drm-fixes' into drm-misc-fixes

v6.10-rc1 is released, forward from v6.9

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

14 files changed, 204 insertions, 90 deletions

diff --git a/arch/x86/entry/Makefile b/arch/x86/entry/Makefile
index c93e7f5c2a06..ce1cc1622385 100644
--- a/arch/x86/entry/Makefile
+++ b/arch/x86/entry/Makefile
@@ -17,7 +17,7 @@ obj-y				+= common.o
 obj-y				+= vdso/
 obj-y				+= vsyscall/
 
-obj-$(CONFIG_PREEMPTION)	+= thunk_$(BITS).o
+obj-$(CONFIG_PREEMPTION)	+= thunk.o
 CFLAGS_entry_fred.o		+= -fno-stack-protector
 CFLAGS_REMOVE_entry_fred.o	+= -pg $(CC_FLAGS_FTRACE)
 obj-$(CONFIG_X86_FRED)		+= entry_64_fred.o entry_fred.o
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 6356060caaf3..51cc9c7cb9bd 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -49,7 +49,7 @@ static __always_inline bool do_syscall_x64(struct pt_regs *regs, int nr)
 
 	if (likely(unr < NR_syscalls)) {
 		unr = array_index_nospec(unr, NR_syscalls);
-		regs->ax = sys_call_table[unr](regs);
+		regs->ax = x64_sys_call(regs, unr);
 		return true;
 	}
 	return false;
@@ -66,7 +66,7 @@ static __always_inline bool do_syscall_x32(struct pt_regs *regs, int nr)
 
 	if (IS_ENABLED(CONFIG_X86_X32_ABI) && likely(xnr < X32_NR_syscalls)) {
 		xnr = array_index_nospec(xnr, X32_NR_syscalls);
-		regs->ax = x32_sys_call_table[xnr](regs);
+		regs->ax = x32_sys_call(regs, xnr);
 		return true;
 	}
 	return false;
@@ -162,7 +162,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs, int nr)
 
 	if (likely(unr < IA32_NR_syscalls)) {
 		unr = array_index_nospec(unr, IA32_NR_syscalls);
-		regs->ax = ia32_sys_call_table[unr](regs);
+		regs->ax = ia32_sys_call(regs, unr);
 	} else if (nr != -1) {
 		regs->ax = __ia32_sys_ni_syscall(regs);
 	}
@@ -189,7 +189,7 @@ static __always_inline bool int80_is_external(void)
 }
 
 /**
- * int80_emulation - 32-bit legacy syscall entry
+ * do_int80_emulation - 32-bit legacy syscall C entry from asm
  *
  * This entry point can be used by 32-bit and 64-bit programs to perform
  * 32-bit system calls.  Instances of INT $0x80 can be found inline in
@@ -207,7 +207,7 @@ static __always_inline bool int80_is_external(void)
  *   eax:				system call number
  *   ebx, ecx, edx, esi, edi, ebp:	arg1 - arg 6
  */
-DEFINE_IDTENTRY_RAW(int80_emulation)
+__visible noinstr void do_int80_emulation(struct pt_regs *regs)
 {
 	int nr;
 
@@ -255,6 +255,71 @@ DEFINE_IDTENTRY_RAW(int80_emulation)
 	instrumentation_end();
 	syscall_exit_to_user_mode(regs);
 }
+
+#ifdef CONFIG_X86_FRED
+/*
+ * A FRED-specific INT80 handler is warranted for the follwing reasons:
+ *
+ * 1) As INT instructions and hardware interrupts are separate event
+ *    types, FRED does not preclude the use of vector 0x80 for external
+ *    interrupts. As a result, the FRED setup code does not reserve
+ *    vector 0x80 and calling int80_is_external() is not merely
+ *    suboptimal but actively incorrect: it could cause a system call
+ *    to be incorrectly ignored.
+ *
+ * 2) It is called only for handling vector 0x80 of event type
+ *    EVENT_TYPE_SWINT and will never be called to handle any external
+ *    interrupt (event type EVENT_TYPE_EXTINT).
+ *
+ * 3) FRED has separate entry flows depending on if the event came from
+ *    user space or kernel space, and because the kernel does not use
+ *    INT insns, the FRED kernel entry handler fred_entry_from_kernel()
+ *    falls through to fred_bad_type() if the event type is
+ *    EVENT_TYPE_SWINT, i.e., INT insns. So if the kernel is handling
+ *    an INT insn, it can only be from a user level.
+ *
+ * 4) int80_emulation() does a CLEAR_BRANCH_HISTORY. While FRED will
+ *    likely take a different approach if it is ever needed: it
+ *    probably belongs in either fred_intx()/ fred_other() or
+ *    asm_fred_entrypoint_user(), depending on if this ought to be done
+ *    for all entries from userspace or only system
+ *    calls.
+ *
+ * 5) INT $0x80 is the fast path for 32-bit system calls under FRED.
+ */
+DEFINE_FREDENTRY_RAW(int80_emulation)
+{
+	int nr;
+
+	enter_from_user_mode(regs);
+
+	instrumentation_begin();
+	add_random_kstack_offset();
+
+	/*
+	 * FRED pushed 0 into regs::orig_ax and regs::ax contains the
+	 * syscall number.
+	 *
+	 * User tracing code (ptrace or signal handlers) might assume
+	 * that the regs::orig_ax contains a 32-bit number on invoking
+	 * a 32-bit syscall.
+	 *
+	 * Establish the syscall convention by saving the 32bit truncated
+	 * syscall number in regs::orig_ax and by invalidating regs::ax.
+	 */
+	regs->orig_ax = regs->ax & GENMASK(31, 0);
+	regs->ax = -ENOSYS;
+
+	nr = syscall_32_enter(regs);
+
+	local_irq_enable();
+	nr = syscall_enter_from_user_mode_work(regs, nr);
+	do_syscall_32_irqs_on(regs, nr);
+
+	instrumentation_end();
+	syscall_exit_to_user_mode(regs);
+}
+#endif
 #else /* CONFIG_IA32_EMULATION */
 
 /* Handles int $0x80 on a 32bit kernel */
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 8af2a26b24f6..1b5be07f8669 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -116,6 +116,7 @@ SYM_INNER_LABEL(entry_SYSCALL_64_after_hwframe, SYM_L_GLOBAL)
 	/* clobbers %rax, make sure it is after saving the syscall nr */
 	IBRS_ENTER
 	UNTRAIN_RET
+	CLEAR_BRANCH_HISTORY
 
 	call	do_syscall_64		/* returns with IRQs disabled */
 
@@ -1491,3 +1492,63 @@ SYM_CODE_START_NOALIGN(rewind_stack_and_make_dead)
 	call	make_task_dead
 SYM_CODE_END(rewind_stack_and_make_dead)
 .popsection
+
+/*
+ * This sequence executes branches in order to remove user branch information
+ * from the branch history tracker in the Branch Predictor, therefore removing
+ * user influence on subsequent BTB lookups.
+ *
+ * It should be used on parts prior to Alder Lake. Newer parts should use the
+ * BHI_DIS_S hardware control instead. If a pre-Alder Lake part is being
+ * virtualized on newer hardware the VMM should protect against BHI attacks by
+ * setting BHI_DIS_S for the guests.
+ *
+ * CALLs/RETs are necessary to prevent Loop Stream Detector(LSD) from engaging
+ * and not clearing the branch history. The call tree looks like:
+ *
+ * call 1
+ *    call 2
+ *      call 2
+ *        call 2
+ *          call 2
+ * 	      call 2
+ * 	      ret
+ * 	    ret
+ *        ret
+ *      ret
+ *    ret
+ * ret
+ *
+ * This means that the stack is non-constant and ORC can't unwind it with %rsp
+ * alone.  Therefore we unconditionally set up the frame pointer, which allows
+ * ORC to unwind properly.
+ *
+ * The alignment is for performance and not for safety, and may be safely
+ * refactored in the future if needed.
+ */
+SYM_FUNC_START(clear_bhb_loop)
+	push	%rbp
+	mov	%rsp, %rbp
+	movl	$5, %ecx
+	ANNOTATE_INTRA_FUNCTION_CALL
+	call	1f
+	jmp	5f
+	.align 64, 0xcc
+	ANNOTATE_INTRA_FUNCTION_CALL
+1:	call	2f
+	RET
+	.align 64, 0xcc
+2:	movl	$5, %eax
+3:	jmp	4f
+	nop
+4:	sub	$1, %eax
+	jnz	3b
+	sub	$1, %ecx
+	jnz	1b
+	RET
+5:	lfence
+	pop	%rbp
+	RET
+SYM_FUNC_END(clear_bhb_loop)
+EXPORT_SYMBOL_GPL(clear_bhb_loop)
+STACK_FRAME_NON_STANDARD(clear_bhb_loop)
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index eabf48c4d4b4..11c9b8efdc4c 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -7,7 +7,6 @@
 #include <asm/asm-offsets.h>
 #include <asm/current.h>
 #include <asm/errno.h>
-#include <asm/ia32_unistd.h>
 #include <asm/thread_info.h>
 #include <asm/segment.h>
 #include <asm/irqflags.h>
@@ -92,6 +91,7 @@ SYM_INNER_LABEL(entry_SYSENTER_compat_after_hwframe, SYM_L_GLOBAL)
 
 	IBRS_ENTER
 	UNTRAIN_RET
+	CLEAR_BRANCH_HISTORY
 
 	/*
 	 * SYSENTER doesn't filter flags, so we need to clear NT and AC
@@ -206,6 +206,7 @@ SYM_INNER_LABEL(entry_SYSCALL_compat_after_hwframe, SYM_L_GLOBAL)
 
 	IBRS_ENTER
 	UNTRAIN_RET
+	CLEAR_BRANCH_HISTORY
 
 	movq	%rsp, %rdi
 	call	do_fast_syscall_32
@@ -276,3 +277,17 @@ SYM_INNER_LABEL(entry_SYSRETL_compat_end, SYM_L_GLOBAL)
 	ANNOTATE_NOENDBR
 	int3
 SYM_CODE_END(entry_SYSCALL_compat)
+
+/*
+ * int 0x80 is used by 32 bit mode as a system call entry. Normally idt entries
+ * point to C routines, however since this is a system call interface the branch
+ * history needs to be scrubbed to protect against BHI attacks, and that
+ * scrubbing needs to take place in assembly code prior to entering any C
+ * routines.
+ */
+SYM_CODE_START(int80_emulation)
+	ANNOTATE_NOENDBR
+	UNWIND_HINT_FUNC
+	CLEAR_BRANCH_HISTORY
+	jmp do_int80_emulation
+SYM_CODE_END(int80_emulation)
diff --git a/arch/x86/entry/entry_fred.c b/arch/x86/entry/entry_fred.c
index ac120cbdaaf2..f004a4dc74c2 100644
--- a/arch/x86/entry/entry_fred.c
+++ b/arch/x86/entry/entry_fred.c
@@ -28,9 +28,9 @@ static noinstr void fred_bad_type(struct pt_regs *regs, unsigned long error_code
 	if (regs->fred_cs.sl > 0) {
 		pr_emerg("PANIC: invalid or fatal FRED event; event type %u "
 			 "vector %u error 0x%lx aux 0x%lx at %04x:%016lx\n",
-			 regs->fred_ss.type, regs->fred_ss.vector, regs->orig_ax,
+			 regs->fred_ss.type, regs->fred_ss.vector, error_code,
 			 fred_event_data(regs), regs->cs, regs->ip);
-		die("invalid or fatal FRED event", regs, regs->orig_ax);
+		die("invalid or fatal FRED event", regs, error_code);
 		panic("invalid or fatal FRED event");
 	} else {
 		unsigned long flags = oops_begin();
@@ -38,10 +38,10 @@ static noinstr void fred_bad_type(struct pt_regs *regs, unsigned long error_code
 
 		pr_alert("BUG: invalid or fatal FRED event; event type %u "
 			 "vector %u error 0x%lx aux 0x%lx at %04x:%016lx\n",
-			 regs->fred_ss.type, regs->fred_ss.vector, regs->orig_ax,
+			 regs->fred_ss.type, regs->fred_ss.vector, error_code,
 			 fred_event_data(regs), regs->cs, regs->ip);
 
-		if (__die("Invalid or fatal FRED event", regs, regs->orig_ax))
+		if (__die("Invalid or fatal FRED event", regs, error_code))
 			sig = 0;
 
 		oops_end(flags, regs, sig);
@@ -66,7 +66,7 @@ static noinstr void fred_intx(struct pt_regs *regs)
 	/* INT80 */
 	case IA32_SYSCALL_VECTOR:
 		if (ia32_enabled())
-			return int80_emulation(regs);
+			return fred_int80_emulation(regs);
 		fallthrough;
 #endif
 
@@ -117,6 +117,8 @@ static idtentry_t sysvec_table[NR_SYSTEM_VECTORS] __ro_after_init = {
 	SYSVEC(POSTED_INTR_VECTOR,		kvm_posted_intr_ipi),
 	SYSVEC(POSTED_INTR_WAKEUP_VECTOR,	kvm_posted_intr_wakeup_ipi),
 	SYSVEC(POSTED_INTR_NESTED_VECTOR,	kvm_posted_intr_nested_ipi),
+
+	SYSVEC(POSTED_MSI_NOTIFICATION_VECTOR,	posted_msi_notification),
 };
 
 static bool fred_setup_done __initdata;
diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index 8cfc9bc73e7f..c2235bae17ef 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -18,8 +18,25 @@
 #include <asm/syscalls_32.h>
 #undef __SYSCALL
 
+/*
+ * The sys_call_table[] is no longer used for system calls, but
+ * kernel/trace/trace_syscalls.c still wants to know the system
+ * call address.
+ */
+#ifdef CONFIG_X86_32
 #define __SYSCALL(nr, sym) __ia32_##sym,
-
-__visible const sys_call_ptr_t ia32_sys_call_table[] = {
+const sys_call_ptr_t sys_call_table[] = {
 #include <asm/syscalls_32.h>
 };
+#undef __SYSCALL
+#endif
+
+#define __SYSCALL(nr, sym) case nr: return __ia32_##sym(regs);
+
+long ia32_sys_call(const struct pt_regs *regs, unsigned int nr)
+{
+	switch (nr) {
+	#include <asm/syscalls_32.h>
+	default: return __ia32_sys_ni_syscall(regs);
+	}
+};
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index be120eec1fc9..33b3f09e6f15 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -11,8 +11,23 @@
 #include <asm/syscalls_64.h>
 #undef __SYSCALL
 
+/*
+ * The sys_call_table[] is no longer used for system calls, but
+ * kernel/trace/trace_syscalls.c still wants to know the system
+ * call address.
+ */
 #define __SYSCALL(nr, sym) __x64_##sym,
-
-asmlinkage const sys_call_ptr_t sys_call_table[] = {
+const sys_call_ptr_t sys_call_table[] = {
 #include <asm/syscalls_64.h>
 };
+#undef __SYSCALL
+
+#define __SYSCALL(nr, sym) case nr: return __x64_##sym(regs);
+
+long x64_sys_call(const struct pt_regs *regs, unsigned int nr)
+{
+	switch (nr) {
+	#include <asm/syscalls_64.h>
+	default: return __x64_sys_ni_syscall(regs);
+	}
+};
diff --git a/arch/x86/entry/syscall_x32.c b/arch/x86/entry/syscall_x32.c
index bdd0e03a1265..03de4a932131 100644
--- a/arch/x86/entry/syscall_x32.c
+++ b/arch/x86/entry/syscall_x32.c
@@ -11,8 +11,12 @@
 #include <asm/syscalls_x32.h>
 #undef __SYSCALL
 
-#define __SYSCALL(nr, sym) __x64_##sym,
+#define __SYSCALL(nr, sym) case nr: return __x64_##sym(regs);
 
-asmlinkage const sys_call_ptr_t x32_sys_call_table[] = {
-#include <asm/syscalls_x32.h>
+long x32_sys_call(const struct pt_regs *regs, unsigned int nr)
+{
+	switch (nr) {
+	#include <asm/syscalls_x32.h>
+	default: return __x64_sys_ni_syscall(regs);
+	}
 };
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 5f8591ce7f25..7fd1f57ad3d3 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -466,3 +466,4 @@
 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
+462	i386	mseal 			sys_mseal
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 7e8d46f4147f..a396f6e6ab5b 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -374,7 +374,7 @@
 450	common	set_mempolicy_home_node	sys_set_mempolicy_home_node
 451	common	cachestat		sys_cachestat
 452	common	fchmodat2		sys_fchmodat2
-453	64	map_shadow_stack	sys_map_shadow_stack
+453	common	map_shadow_stack	sys_map_shadow_stack
 454	common	futex_wake		sys_futex_wake
 455	common	futex_wait		sys_futex_wait
 456	common	futex_requeue		sys_futex_requeue
@@ -383,6 +383,7 @@
 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
+462 	common  mseal			sys_mseal
 
 #
 # Due to a historical design error, certain syscalls are numbered differently
diff --git a/arch/x86/entry/thunk_64.S b/arch/x86/entry/thunk.S
index 119ebdc3d362..119ebdc3d362 100644
--- a/arch/x86/entry/thunk_64.S
+++ b/arch/x86/entry/thunk.S
diff --git a/arch/x86/entry/thunk_32.S b/arch/x86/entry/thunk_32.S
deleted file mode 100644
index da37f42f4549..000000000000
--- a/arch/x86/entry/thunk_32.S
+++ /dev/null
@@ -1,18 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Trampoline to trace irqs off. (otherwise CALLER_ADDR1 might crash)
- * Copyright 2008 by Steven Rostedt, Red Hat, Inc
- *  (inspired by Andi Kleen's thunk_64.S)
- */
-
-#include <linux/export.h>
-#include <linux/linkage.h>
-#include <asm/asm.h>
-
-#include "calling.h"
-
-THUNK preempt_schedule_thunk, preempt_schedule
-THUNK preempt_schedule_notrace_thunk, preempt_schedule_notrace
-EXPORT_SYMBOL(preempt_schedule_thunk)
-EXPORT_SYMBOL(preempt_schedule_notrace_thunk)
-
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index fd63051bbbbb..215a1b202a91 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -6,20 +6,6 @@
 # Include the generic Makefile to check the built vDSO:
 include $(srctree)/lib/vdso/Makefile
 
-# Sanitizer runtimes are unavailable and cannot be linked here.
-KASAN_SANITIZE			:= n
-KMSAN_SANITIZE_vclock_gettime.o := n
-KMSAN_SANITIZE_vdso32/vclock_gettime.o	:= n
-KMSAN_SANITIZE_vgetcpu.o	:= n
-KMSAN_SANITIZE_vdso32/vgetcpu.o	:= n
-
-UBSAN_SANITIZE			:= n
-KCSAN_SANITIZE			:= n
-OBJECT_FILES_NON_STANDARD	:= y
-
-# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
-KCOV_INSTRUMENT		:= n
-
 # Files to link into the vDSO:
 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
 vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
@@ -28,22 +14,12 @@ vobjs-$(CONFIG_X86_SGX)	+= vsgx.o
 
 # Files to link into the kernel:
 obj-y						+= vma.o extable.o
-KASAN_SANITIZE_vma.o				:= y
-UBSAN_SANITIZE_vma.o				:= y
-KCSAN_SANITIZE_vma.o				:= y
-
-OBJECT_FILES_NON_STANDARD_vma.o			:= n
-OBJECT_FILES_NON_STANDARD_extable.o		:= n
 
 # vDSO images to build:
 obj-$(CONFIG_X86_64)				+= vdso-image-64.o
 obj-$(CONFIG_X86_X32_ABI)			+= vdso-image-x32.o
 obj-$(CONFIG_COMPAT_32)				+= vdso-image-32.o vdso32-setup.o
 
-OBJECT_FILES_NON_STANDARD_vdso-image-32.o	:= n
-OBJECT_FILES_NON_STANDARD_vdso-image-64.o	:= n
-OBJECT_FILES_NON_STANDARD_vdso32-setup.o	:= n
-
 vobjs := $(addprefix $(obj)/, $(vobjs-y))
 vobjs32 := $(addprefix $(obj)/, $(vobjs32-y))
 
@@ -175,11 +151,10 @@ quiet_cmd_vdso = VDSO    $@
       cmd_vdso = $(LD) -o $@ \
 		       $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
 		       -T $(filter %.lds,$^) $(filter %.o,$^) && \
-		 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
+		 sh $(src)/checkundef.sh '$(NM)' '$@'
 
 VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 \
 	$(call ld-option, --eh-frame-hdr) -Bsymbolic -z noexecstack
-GCOV_PROFILE := n
 
 quiet_cmd_vdso_and_check = VDSO    $@
       cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index a3c0df11d0e6..2fb7d53cf333 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -98,11 +98,6 @@ static int addr_to_vsyscall_nr(unsigned long addr)
 
 static bool write_ok_or_segv(unsigned long ptr, size_t size)
 {
-	/*
-	 * XXX: if access_ok, get_user, and put_user handled
-	 * sig_on_uaccess_err, this could go away.
-	 */
-
 	if (!access_ok((void __user *)ptr, size)) {
 		struct thread_struct *thread = &current->thread;
 
@@ -120,10 +115,8 @@ static bool write_ok_or_segv(unsigned long ptr, size_t size)
 bool emulate_vsyscall(unsigned long error_code,
 		      struct pt_regs *regs, unsigned long address)
 {
-	struct task_struct *tsk;
 	unsigned long caller;
 	int vsyscall_nr, syscall_nr, tmp;
-	int prev_sig_on_uaccess_err;
 	long ret;
 	unsigned long orig_dx;
 
@@ -172,8 +165,6 @@ bool emulate_vsyscall(unsigned long error_code,
 		goto sigsegv;
 	}
 
-	tsk = current;
-
 	/*
 	 * Check for access_ok violations and find the syscall nr.
 	 *
@@ -234,12 +225,8 @@ bool emulate_vsyscall(unsigned long error_code,
 		goto do_ret;  /* skip requested */
 
 	/*
-	 * With a real vsyscall, page faults cause SIGSEGV.  We want to
-	 * preserve that behavior to make writing exploits harder.
+	 * With a real vsyscall, page faults cause SIGSEGV.
 	 */
-	prev_sig_on_uaccess_err = current->thread.sig_on_uaccess_err;
-	current->thread.sig_on_uaccess_err = 1;
-
 	ret = -EFAULT;
 	switch (vsyscall_nr) {
 	case 0:
@@ -262,23 +249,12 @@ bool emulate_vsyscall(unsigned long error_code,
 		break;
 	}
 
-	current->thread.sig_on_uaccess_err = prev_sig_on_uaccess_err;
-
 check_fault:
 	if (ret == -EFAULT) {
 		/* Bad news -- userspace fed a bad pointer to a vsyscall. */
 		warn_bad_vsyscall(KERN_INFO, regs,
 				  "vsyscall fault (exploit attempt?)");
-
-		/*
-		 * If we failed to generate a signal for any reason,
-		 * generate one here.  (This should be impossible.)
-		 */
-		if (WARN_ON_ONCE(!sigismember(&tsk->pending.signal, SIGBUS) &&
-				 !sigismember(&tsk->pending.signal, SIGSEGV)))
-			goto sigsegv;
-
-		return true;  /* Don't emulate the ret. */
+		goto sigsegv;
 	}
 
 	regs->ax = ret;