Merge branch 'timers/urgent' into timers/core

Pick up urgent bug fix and resolve the conflict.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

8 files changed, 759 insertions, 34 deletions

diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index ae0272f9a091..e6acc281dd37 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -46,7 +46,7 @@ $(OBJTOOL_IN): fixdep FORCE
 	@$(MAKE) $(build)=objtool
 
 $(OBJTOOL): $(LIBSUBCMD) $(OBJTOOL_IN)
-	@./sync-check.sh
+	@$(CONFIG_SHELL) ./sync-check.sh
 	$(QUIET_LINK)$(CC) $(OBJTOOL_IN) $(LDFLAGS) -o $@
 
 
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 9b341584eb1b..f40d46e24bcc 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -428,6 +428,40 @@ static void add_ignores(struct objtool_file *file)
 }
 
 /*
+ * FIXME: For now, just ignore any alternatives which add retpolines.  This is
+ * a temporary hack, as it doesn't allow ORC to unwind from inside a retpoline.
+ * But it at least allows objtool to understand the control flow *around* the
+ * retpoline.
+ */
+static int add_nospec_ignores(struct objtool_file *file)
+{
+	struct section *sec;
+	struct rela *rela;
+	struct instruction *insn;
+
+	sec = find_section_by_name(file->elf, ".rela.discard.nospec");
+	if (!sec)
+		return 0;
+
+	list_for_each_entry(rela, &sec->rela_list, list) {
+		if (rela->sym->type != STT_SECTION) {
+			WARN("unexpected relocation symbol type in %s", sec->name);
+			return -1;
+		}
+
+		insn = find_insn(file, rela->sym->sec, rela->addend);
+		if (!insn) {
+			WARN("bad .discard.nospec entry");
+			return -1;
+		}
+
+		insn->ignore_alts = true;
+	}
+
+	return 0;
+}
+
+/*
  * Find the destination instructions for all jumps.
  */
 static int add_jump_destinations(struct objtool_file *file)
@@ -456,6 +490,13 @@ static int add_jump_destinations(struct objtool_file *file)
 		} else if (rela->sym->sec->idx) {
 			dest_sec = rela->sym->sec;
 			dest_off = rela->sym->sym.st_value + rela->addend + 4;
+		} else if (strstr(rela->sym->name, "_indirect_thunk_")) {
+			/*
+			 * Retpoline jumps are really dynamic jumps in
+			 * disguise, so convert them accordingly.
+			 */
+			insn->type = INSN_JUMP_DYNAMIC;
+			continue;
 		} else {
 			/* sibling call */
 			insn->jump_dest = 0;
@@ -502,11 +543,18 @@ static int add_call_destinations(struct objtool_file *file)
 			dest_off = insn->offset + insn->len + insn->immediate;
 			insn->call_dest = find_symbol_by_offset(insn->sec,
 								dest_off);
+			/*
+			 * FIXME: Thanks to retpolines, it's now considered
+			 * normal for a function to call within itself.  So
+			 * disable this warning for now.
+			 */
+#if 0
 			if (!insn->call_dest) {
 				WARN_FUNC("can't find call dest symbol at offset 0x%lx",
 					  insn->sec, insn->offset, dest_off);
 				return -1;
 			}
+#endif
 		} else if (rela->sym->type == STT_SECTION) {
 			insn->call_dest = find_symbol_by_offset(rela->sym->sec,
 								rela->addend+4);
@@ -671,12 +719,6 @@ static int add_special_section_alts(struct objtool_file *file)
 		return ret;
 
 	list_for_each_entry_safe(special_alt, tmp, &special_alts, list) {
-		alt = malloc(sizeof(*alt));
-		if (!alt) {
-			WARN("malloc failed");
-			ret = -1;
-			goto out;
-		}
 
 		orig_insn = find_insn(file, special_alt->orig_sec,
 				      special_alt->orig_off);
@@ -687,6 +729,10 @@ static int add_special_section_alts(struct objtool_file *file)
 			goto out;
 		}
 
+		/* Ignore retpoline alternatives. */
+		if (orig_insn->ignore_alts)
+			continue;
+
 		new_insn = NULL;
 		if (!special_alt->group || special_alt->new_len) {
 			new_insn = find_insn(file, special_alt->new_sec,
@@ -712,6 +758,13 @@ static int add_special_section_alts(struct objtool_file *file)
 				goto out;
 		}
 
+		alt = malloc(sizeof(*alt));
+		if (!alt) {
+			WARN("malloc failed");
+			ret = -1;
+			goto out;
+		}
+
 		alt->insn = new_insn;
 		list_add_tail(&alt->list, &orig_insn->alts);
 
@@ -1028,6 +1081,10 @@ static int decode_sections(struct objtool_file *file)
 
 	add_ignores(file);
 
+	ret = add_nospec_ignores(file);
+	if (ret)
+		return ret;
+
 	ret = add_jump_destinations(file);
 	if (ret)
 		return ret;
diff --git a/tools/objtool/check.h b/tools/objtool/check.h
index 47d9ea70a83d..dbadb304a410 100644
--- a/tools/objtool/check.h
+++ b/tools/objtool/check.h
@@ -44,7 +44,7 @@ struct instruction {
 	unsigned int len;
 	unsigned char type;
 	unsigned long immediate;
-	bool alt_group, visited, dead_end, ignore, hint, save, restore;
+	bool alt_group, visited, dead_end, ignore, hint, save, restore, ignore_alts;
 	struct symbol *call_dest;
 	struct instruction *jump_dest;
 	struct list_head alts;
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 24460155c82c..c1c338661699 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -26,6 +26,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <errno.h>
 
 #include "elf.h"
 #include "warn.h"
@@ -358,7 +359,8 @@ struct elf *elf_open(const char *name, int flags)
 
 	elf->fd = open(name, flags);
 	if (elf->fd == -1) {
-		perror("open");
+		fprintf(stderr, "objtool: Can't open '%s': %s\n",
+			name, strerror(errno));
 		goto err;
 	}
 
diff --git a/tools/testing/selftests/bpf/test_align.c b/tools/testing/selftests/bpf/test_align.c
index 8591c89c0828..471bbbdb94db 100644
--- a/tools/testing/selftests/bpf/test_align.c
+++ b/tools/testing/selftests/bpf/test_align.c
@@ -474,27 +474,7 @@ static struct bpf_align_test tests[] = {
 		.result = REJECT,
 		.matches = {
 			{4, "R5=pkt(id=0,off=0,r=0,imm=0)"},
-			/* ptr & 0x40 == either 0 or 0x40 */
-			{5, "R5=inv(id=0,umax_value=64,var_off=(0x0; 0x40))"},
-			/* ptr << 2 == unknown, (4n) */
-			{7, "R5=inv(id=0,smax_value=9223372036854775804,umax_value=18446744073709551612,var_off=(0x0; 0xfffffffffffffffc))"},
-			/* (4n) + 14 == (4n+2).  We blow our bounds, because
-			 * the add could overflow.
-			 */
-			{8, "R5=inv(id=0,var_off=(0x2; 0xfffffffffffffffc))"},
-			/* Checked s>=0 */
-			{10, "R5=inv(id=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"},
-			/* packet pointer + nonnegative (4n+2) */
-			{12, "R6=pkt(id=1,off=0,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"},
-			{14, "R4=pkt(id=1,off=4,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"},
-			/* NET_IP_ALIGN + (4n+2) == (4n), alignment is fine.
-			 * We checked the bounds, but it might have been able
-			 * to overflow if the packet pointer started in the
-			 * upper half of the address space.
-			 * So we did not get a 'range' on R6, and the access
-			 * attempt will fail.
-			 */
-			{16, "R6=pkt(id=1,off=0,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"},
+			/* R5 bitwise operator &= on pointer prohibited */
 		}
 	},
 	{
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index b51017404c62..5ed4175c4ff8 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -273,6 +273,46 @@ static struct bpf_test tests[] = {
 		.result = REJECT,
 	},
 	{
+		"arsh32 on imm",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_ALU32_IMM(BPF_ARSH, BPF_REG_0, 5),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "BPF_ARSH not supported for 32 bit ALU",
+	},
+	{
+		"arsh32 on reg",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_MOV64_IMM(BPF_REG_1, 5),
+			BPF_ALU32_REG(BPF_ARSH, BPF_REG_0, BPF_REG_1),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "BPF_ARSH not supported for 32 bit ALU",
+	},
+	{
+		"arsh64 on imm",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_ALU64_IMM(BPF_ARSH, BPF_REG_0, 5),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+	},
+	{
+		"arsh64 on reg",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_MOV64_IMM(BPF_REG_1, 5),
+			BPF_ALU64_REG(BPF_ARSH, BPF_REG_0, BPF_REG_1),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+	},
+	{
 		"no bpf_exit",
 		.insns = {
 			BPF_ALU64_REG(BPF_MOV, BPF_REG_0, BPF_REG_2),
@@ -2553,6 +2593,29 @@ static struct bpf_test tests[] = {
 		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
 	},
 	{
+		"context stores via ST",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_ST_MEM(BPF_DW, BPF_REG_1, offsetof(struct __sk_buff, mark), 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "BPF_ST stores into R1 context is not allowed",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	},
+	{
+		"context stores via XADD",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_W, BPF_REG_1,
+				     BPF_REG_0, offsetof(struct __sk_buff, mark), 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "BPF_XADD stores into R1 context is not allowed",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	},
+	{
 		"direct packet access: test1",
 		.insns = {
 			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
@@ -4272,7 +4335,8 @@ static struct bpf_test tests[] = {
 		.fixup_map1 = { 2 },
 		.errstr_unpriv = "R2 leaks addr into mem",
 		.result_unpriv = REJECT,
-		.result = ACCEPT,
+		.result = REJECT,
+		.errstr = "BPF_XADD stores into R1 context is not allowed",
 	},
 	{
 		"leak pointer into ctx 2",
@@ -4286,7 +4350,8 @@ static struct bpf_test tests[] = {
 		},
 		.errstr_unpriv = "R10 leaks addr into mem",
 		.result_unpriv = REJECT,
-		.result = ACCEPT,
+		.result = REJECT,
+		.errstr = "BPF_XADD stores into R1 context is not allowed",
 	},
 	{
 		"leak pointer into ctx 3",
@@ -6667,7 +6732,7 @@ static struct bpf_test tests[] = {
 			BPF_JMP_IMM(BPF_JA, 0, 0, -7),
 		},
 		.fixup_map1 = { 4 },
-		.errstr = "unbounded min value",
+		.errstr = "R0 invalid mem access 'inv'",
 		.result = REJECT,
 	},
 	{
@@ -8569,6 +8634,127 @@ static struct bpf_test tests[] = {
 		.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
 	},
 	{
+		"check deducing bounds from const, 1",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 1, 0),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "R0 tried to subtract pointer from scalar",
+	},
+	{
+		"check deducing bounds from const, 2",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 1, 1),
+			BPF_EXIT_INSN(),
+			BPF_JMP_IMM(BPF_JSLE, BPF_REG_0, 1, 1),
+			BPF_EXIT_INSN(),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_1, BPF_REG_0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+	},
+	{
+		"check deducing bounds from const, 3",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_JMP_IMM(BPF_JSLE, BPF_REG_0, 0, 0),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "R0 tried to subtract pointer from scalar",
+	},
+	{
+		"check deducing bounds from const, 4",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_JMP_IMM(BPF_JSLE, BPF_REG_0, 0, 1),
+			BPF_EXIT_INSN(),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 0, 1),
+			BPF_EXIT_INSN(),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_1, BPF_REG_0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+	},
+	{
+		"check deducing bounds from const, 5",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 0, 1),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "R0 tried to subtract pointer from scalar",
+	},
+	{
+		"check deducing bounds from const, 6",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 0, 1),
+			BPF_EXIT_INSN(),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "R0 tried to subtract pointer from scalar",
+	},
+	{
+		"check deducing bounds from const, 7",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, ~0),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 0, 0),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_1, BPF_REG_0),
+			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+				    offsetof(struct __sk_buff, mark)),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "dereference of modified ctx ptr",
+	},
+	{
+		"check deducing bounds from const, 8",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, ~0),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 0, 1),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+				    offsetof(struct __sk_buff, mark)),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "dereference of modified ctx ptr",
+	},
+	{
+		"check deducing bounds from const, 9",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 0, 0),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "R0 tried to subtract pointer from scalar",
+	},
+	{
+		"check deducing bounds from const, 10",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_JMP_IMM(BPF_JSLE, BPF_REG_0, 0, 0),
+			/* Marks reg as unknown. */
+			BPF_ALU64_IMM(BPF_NEG, BPF_REG_0, 0),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "math between ctx pointer and register with unbounded min value is not allowed",
+	},
+	{
 		"bpf_exit with invalid return code. test1",
 		.insns = {
 			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, 0),
diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index 939a337128db..5d4f10ac2af2 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -7,7 +7,7 @@ include ../lib.mk
 
 TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt ptrace_syscall test_mremap_vdso \
 			check_initial_reg_state sigreturn ldt_gdt iopl mpx-mini-test ioperm \
-			protection_keys test_vdso
+			protection_keys test_vdso test_vsyscall
 TARGETS_C_32BIT_ONLY := entry_from_vm86 syscall_arg_fault test_syscall_vdso unwind_vdso \
 			test_FCMOV test_FCOMI test_FISTTP \
 			vdso_restorer
diff --git a/tools/testing/selftests/x86/test_vsyscall.c b/tools/testing/selftests/x86/test_vsyscall.c
new file mode 100644
index 000000000000..7a744fa7b786
--- /dev/null
+++ b/tools/testing/selftests/x86/test_vsyscall.c
@@ -0,0 +1,500 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <sys/time.h>
+#include <time.h>
+#include <stdlib.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <dlfcn.h>
+#include <string.h>
+#include <inttypes.h>
+#include <signal.h>
+#include <sys/ucontext.h>
+#include <errno.h>
+#include <err.h>
+#include <sched.h>
+#include <stdbool.h>
+#include <setjmp.h>
+
+#ifdef __x86_64__
+# define VSYS(x) (x)
+#else
+# define VSYS(x) 0
+#endif
+
+#ifndef SYS_getcpu
+# ifdef __x86_64__
+#  define SYS_getcpu 309
+# else
+#  define SYS_getcpu 318
+# endif
+#endif
+
+static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *),
+		       int flags)
+{
+	struct sigaction sa;
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_sigaction = handler;
+	sa.sa_flags = SA_SIGINFO | flags;
+	sigemptyset(&sa.sa_mask);
+	if (sigaction(sig, &sa, 0))
+		err(1, "sigaction");
+}
+
+/* vsyscalls and vDSO */
+bool should_read_vsyscall = false;
+
+typedef long (*gtod_t)(struct timeval *tv, struct timezone *tz);
+gtod_t vgtod = (gtod_t)VSYS(0xffffffffff600000);
+gtod_t vdso_gtod;
+
+typedef int (*vgettime_t)(clockid_t, struct timespec *);
+vgettime_t vdso_gettime;
+
+typedef long (*time_func_t)(time_t *t);
+time_func_t vtime = (time_func_t)VSYS(0xffffffffff600400);
+time_func_t vdso_time;
+
+typedef long (*getcpu_t)(unsigned *, unsigned *, void *);
+getcpu_t vgetcpu = (getcpu_t)VSYS(0xffffffffff600800);
+getcpu_t vdso_getcpu;
+
+static void init_vdso(void)
+{
+	void *vdso = dlopen("linux-vdso.so.1", RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
+	if (!vdso)
+		vdso = dlopen("linux-gate.so.1", RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
+	if (!vdso) {
+		printf("[WARN]\tfailed to find vDSO\n");
+		return;
+	}
+
+	vdso_gtod = (gtod_t)dlsym(vdso, "__vdso_gettimeofday");
+	if (!vdso_gtod)
+		printf("[WARN]\tfailed to find gettimeofday in vDSO\n");
+
+	vdso_gettime = (vgettime_t)dlsym(vdso, "__vdso_clock_gettime");
+	if (!vdso_gettime)
+		printf("[WARN]\tfailed to find clock_gettime in vDSO\n");
+
+	vdso_time = (time_func_t)dlsym(vdso, "__vdso_time");
+	if (!vdso_time)
+		printf("[WARN]\tfailed to find time in vDSO\n");
+
+	vdso_getcpu = (getcpu_t)dlsym(vdso, "__vdso_getcpu");
+	if (!vdso_getcpu) {
+		/* getcpu() was never wired up in the 32-bit vDSO. */
+		printf("[%s]\tfailed to find getcpu in vDSO\n",
+		       sizeof(long) == 8 ? "WARN" : "NOTE");
+	}
+}
+
+static int init_vsys(void)
+{
+#ifdef __x86_64__
+	int nerrs = 0;
+	FILE *maps;
+	char line[128];
+	bool found = false;
+
+	maps = fopen("/proc/self/maps", "r");
+	if (!maps) {
+		printf("[WARN]\tCould not open /proc/self/maps -- assuming vsyscall is r-x\n");
+		should_read_vsyscall = true;
+		return 0;
+	}
+
+	while (fgets(line, sizeof(line), maps)) {
+		char r, x;
+		void *start, *end;
+		char name[128];
+		if (sscanf(line, "%p-%p %c-%cp %*x %*x:%*x %*u %s",
+			   &start, &end, &r, &x, name) != 5)
+			continue;
+
+		if (strcmp(name, "[vsyscall]"))
+			continue;
+
+		printf("\tvsyscall map: %s", line);
+
+		if (start != (void *)0xffffffffff600000 ||
+		    end != (void *)0xffffffffff601000) {
+			printf("[FAIL]\taddress range is nonsense\n");
+			nerrs++;
+		}
+
+		printf("\tvsyscall permissions are %c-%c\n", r, x);
+		should_read_vsyscall = (r == 'r');
+		if (x != 'x') {
+			vgtod = NULL;
+			vtime = NULL;
+			vgetcpu = NULL;
+		}
+
+		found = true;
+		break;
+	}
+
+	fclose(maps);
+
+	if (!found) {
+		printf("\tno vsyscall map in /proc/self/maps\n");
+		should_read_vsyscall = false;
+		vgtod = NULL;
+		vtime = NULL;
+		vgetcpu = NULL;
+	}
+
+	return nerrs;
+#else
+	return 0;
+#endif
+}
+
+/* syscalls */
+static inline long sys_gtod(struct timeval *tv, struct timezone *tz)
+{
+	return syscall(SYS_gettimeofday, tv, tz);
+}
+
+static inline int sys_clock_gettime(clockid_t id, struct timespec *ts)
+{
+	return syscall(SYS_clock_gettime, id, ts);
+}
+
+static inline long sys_time(time_t *t)
+{
+	return syscall(SYS_time, t);
+}
+
+static inline long sys_getcpu(unsigned * cpu, unsigned * node,
+			      void* cache)
+{
+	return syscall(SYS_getcpu, cpu, node, cache);
+}
+
+static jmp_buf jmpbuf;
+
+static void sigsegv(int sig, siginfo_t *info, void *ctx_void)
+{
+	siglongjmp(jmpbuf, 1);
+}
+
+static double tv_diff(const struct timeval *a, const struct timeval *b)
+{
+	return (double)(a->tv_sec - b->tv_sec) +
+		(double)((int)a->tv_usec - (int)b->tv_usec) * 1e-6;
+}
+
+static int check_gtod(const struct timeval *tv_sys1,
+		      const struct timeval *tv_sys2,
+		      const struct timezone *tz_sys,
+		      const char *which,
+		      const struct timeval *tv_other,
+		      const struct timezone *tz_other)
+{
+	int nerrs = 0;
+	double d1, d2;
+
+	if (tz_other && (tz_sys->tz_minuteswest != tz_other->tz_minuteswest || tz_sys->tz_dsttime != tz_other->tz_dsttime)) {
+		printf("[FAIL] %s tz mismatch\n", which);
+		nerrs++;
+	}
+
+	d1 = tv_diff(tv_other, tv_sys1);
+	d2 = tv_diff(tv_sys2, tv_other); 
+	printf("\t%s time offsets: %lf %lf\n", which, d1, d2);
+
+	if (d1 < 0 || d2 < 0) {
+		printf("[FAIL]\t%s time was inconsistent with the syscall\n", which);
+		nerrs++;
+	} else {
+		printf("[OK]\t%s gettimeofday()'s timeval was okay\n", which);
+	}
+
+	return nerrs;
+}
+
+static int test_gtod(void)
+{
+	struct timeval tv_sys1, tv_sys2, tv_vdso, tv_vsys;
+	struct timezone tz_sys, tz_vdso, tz_vsys;
+	long ret_vdso = -1;
+	long ret_vsys = -1;
+	int nerrs = 0;
+
+	printf("[RUN]\ttest gettimeofday()\n");
+
+	if (sys_gtod(&tv_sys1, &tz_sys) != 0)
+		err(1, "syscall gettimeofday");
+	if (vdso_gtod)
+		ret_vdso = vdso_gtod(&tv_vdso, &tz_vdso);
+	if (vgtod)
+		ret_vsys = vgtod(&tv_vsys, &tz_vsys);
+	if (sys_gtod(&tv_sys2, &tz_sys) != 0)
+		err(1, "syscall gettimeofday");
+
+	if (vdso_gtod) {
+		if (ret_vdso == 0) {
+			nerrs += check_gtod(&tv_sys1, &tv_sys2, &tz_sys, "vDSO", &tv_vdso, &tz_vdso);
+		} else {
+			printf("[FAIL]\tvDSO gettimeofday() failed: %ld\n", ret_vdso);
+			nerrs++;
+		}
+	}
+
+	if (vgtod) {
+		if (ret_vsys == 0) {
+			nerrs += check_gtod(&tv_sys1, &tv_sys2, &tz_sys, "vsyscall", &tv_vsys, &tz_vsys);
+		} else {
+			printf("[FAIL]\tvsys gettimeofday() failed: %ld\n", ret_vsys);
+			nerrs++;
+		}
+	}
+
+	return nerrs;
+}
+
+static int test_time(void) {
+	int nerrs = 0;
+
+	printf("[RUN]\ttest time()\n");
+	long t_sys1, t_sys2, t_vdso = 0, t_vsys = 0;
+	long t2_sys1 = -1, t2_sys2 = -1, t2_vdso = -1, t2_vsys = -1;
+	t_sys1 = sys_time(&t2_sys1);
+	if (vdso_time)
+		t_vdso = vdso_time(&t2_vdso);
+	if (vtime)
+		t_vsys = vtime(&t2_vsys);
+	t_sys2 = sys_time(&t2_sys2);
+	if (t_sys1 < 0 || t_sys1 != t2_sys1 || t_sys2 < 0 || t_sys2 != t2_sys2) {
+		printf("[FAIL]\tsyscall failed (ret1:%ld output1:%ld ret2:%ld output2:%ld)\n", t_sys1, t2_sys1, t_sys2, t2_sys2);
+		nerrs++;
+		return nerrs;
+	}
+
+	if (vdso_time) {
+		if (t_vdso < 0 || t_vdso != t2_vdso) {
+			printf("[FAIL]\tvDSO failed (ret:%ld output:%ld)\n", t_vdso, t2_vdso);
+			nerrs++;
+		} else if (t_vdso < t_sys1 || t_vdso > t_sys2) {
+			printf("[FAIL]\tvDSO returned the wrong time (%ld %ld %ld)\n", t_sys1, t_vdso, t_sys2);
+			nerrs++;
+		} else {
+			printf("[OK]\tvDSO time() is okay\n");
+		}
+	}
+
+	if (vtime) {
+		if (t_vsys < 0 || t_vsys != t2_vsys) {
+			printf("[FAIL]\tvsyscall failed (ret:%ld output:%ld)\n", t_vsys, t2_vsys);
+			nerrs++;
+		} else if (t_vsys < t_sys1 || t_vsys > t_sys2) {
+			printf("[FAIL]\tvsyscall returned the wrong time (%ld %ld %ld)\n", t_sys1, t_vsys, t_sys2);
+			nerrs++;
+		} else {
+			printf("[OK]\tvsyscall time() is okay\n");
+		}
+	}
+
+	return nerrs;
+}
+
+static int test_getcpu(int cpu)
+{
+	int nerrs = 0;
+	long ret_sys, ret_vdso = -1, ret_vsys = -1;
+
+	printf("[RUN]\tgetcpu() on CPU %d\n", cpu);
+
+	cpu_set_t cpuset;
+	CPU_ZERO(&cpuset);
+	CPU_SET(cpu, &cpuset);
+	if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) {
+		printf("[SKIP]\tfailed to force CPU %d\n", cpu);
+		return nerrs;
+	}
+
+	unsigned cpu_sys, cpu_vdso, cpu_vsys, node_sys, node_vdso, node_vsys;
+	unsigned node = 0;
+	bool have_node = false;
+	ret_sys = sys_getcpu(&cpu_sys, &node_sys, 0);
+	if (vdso_getcpu)
+		ret_vdso = vdso_getcpu(&cpu_vdso, &node_vdso, 0);
+	if (vgetcpu)
+		ret_vsys = vgetcpu(&cpu_vsys, &node_vsys, 0);
+
+	if (ret_sys == 0) {
+		if (cpu_sys != cpu) {
+			printf("[FAIL]\tsyscall reported CPU %hu but should be %d\n", cpu_sys, cpu);
+			nerrs++;
+		}
+
+		have_node = true;
+		node = node_sys;
+	}
+
+	if (vdso_getcpu) {
+		if (ret_vdso) {
+			printf("[FAIL]\tvDSO getcpu() failed\n");
+			nerrs++;
+		} else {
+			if (!have_node) {
+				have_node = true;
+				node = node_vdso;
+			}
+
+			if (cpu_vdso != cpu) {
+				printf("[FAIL]\tvDSO reported CPU %hu but should be %d\n", cpu_vdso, cpu);
+				nerrs++;
+			} else {
+				printf("[OK]\tvDSO reported correct CPU\n");
+			}
+
+			if (node_vdso != node) {
+				printf("[FAIL]\tvDSO reported node %hu but should be %hu\n", node_vdso, node);
+				nerrs++;
+			} else {
+				printf("[OK]\tvDSO reported correct node\n");
+			}
+		}
+	}
+
+	if (vgetcpu) {
+		if (ret_vsys) {
+			printf("[FAIL]\tvsyscall getcpu() failed\n");
+			nerrs++;
+		} else {
+			if (!have_node) {
+				have_node = true;
+				node = node_vsys;
+			}
+
+			if (cpu_vsys != cpu) {
+				printf("[FAIL]\tvsyscall reported CPU %hu but should be %d\n", cpu_vsys, cpu);
+				nerrs++;
+			} else {
+				printf("[OK]\tvsyscall reported correct CPU\n");
+			}
+
+			if (node_vsys != node) {
+				printf("[FAIL]\tvsyscall reported node %hu but should be %hu\n", node_vsys, node);
+				nerrs++;
+			} else {
+				printf("[OK]\tvsyscall reported correct node\n");
+			}
+		}
+	}
+
+	return nerrs;
+}
+
+static int test_vsys_r(void)
+{
+#ifdef __x86_64__
+	printf("[RUN]\tChecking read access to the vsyscall page\n");
+	bool can_read;
+	if (sigsetjmp(jmpbuf, 1) == 0) {
+		*(volatile int *)0xffffffffff600000;
+		can_read = true;
+	} else {
+		can_read = false;
+	}
+
+	if (can_read && !should_read_vsyscall) {
+		printf("[FAIL]\tWe have read access, but we shouldn't\n");
+		return 1;
+	} else if (!can_read && should_read_vsyscall) {
+		printf("[FAIL]\tWe don't have read access, but we should\n");
+		return 1;
+	} else {
+		printf("[OK]\tgot expected result\n");
+	}
+#endif
+
+	return 0;
+}
+
+
+#ifdef __x86_64__
+#define X86_EFLAGS_TF (1UL << 8)
+static volatile sig_atomic_t num_vsyscall_traps;
+
+static unsigned long get_eflags(void)
+{
+	unsigned long eflags;
+	asm volatile ("pushfq\n\tpopq %0" : "=rm" (eflags));
+	return eflags;
+}
+
+static void set_eflags(unsigned long eflags)
+{
+	asm volatile ("pushq %0\n\tpopfq" : : "rm" (eflags) : "flags");
+}
+
+static void sigtrap(int sig, siginfo_t *info, void *ctx_void)
+{
+	ucontext_t *ctx = (ucontext_t *)ctx_void;
+	unsigned long ip = ctx->uc_mcontext.gregs[REG_RIP];
+
+	if (((ip ^ 0xffffffffff600000UL) & ~0xfffUL) == 0)
+		num_vsyscall_traps++;
+}
+
+static int test_native_vsyscall(void)
+{
+	time_t tmp;
+	bool is_native;
+
+	if (!vtime)
+		return 0;
+
+	printf("[RUN]\tchecking for native vsyscall\n");
+	sethandler(SIGTRAP, sigtrap, 0);
+	set_eflags(get_eflags() | X86_EFLAGS_TF);
+	vtime(&tmp);
+	set_eflags(get_eflags() & ~X86_EFLAGS_TF);
+
+	/*
+	 * If vsyscalls are emulated, we expect a single trap in the
+	 * vsyscall page -- the call instruction will trap with RIP
+	 * pointing to the entry point before emulation takes over.
+	 * In native mode, we expect two traps, since whatever code
+	 * the vsyscall page contains will be more than just a ret
+	 * instruction.
+	 */
+	is_native = (num_vsyscall_traps > 1);
+
+	printf("\tvsyscalls are %s (%d instructions in vsyscall page)\n",
+	       (is_native ? "native" : "emulated"),
+	       (int)num_vsyscall_traps);
+
+	return 0;
+}
+#endif
+
+int main(int argc, char **argv)
+{
+	int nerrs = 0;
+
+	init_vdso();
+	nerrs += init_vsys();
+
+	nerrs += test_gtod();
+	nerrs += test_time();
+	nerrs += test_getcpu(0);
+	nerrs += test_getcpu(1);
+
+	sethandler(SIGSEGV, sigsegv, 0);
+	nerrs += test_vsys_r();
+
+#ifdef __x86_64__
+	nerrs += test_native_vsyscall();
+#endif
+
+	return nerrs ? 1 : 0;
+}