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-rw-r--r--tools/testing/selftests/x86/Makefile6
-rw-r--r--tools/testing/selftests/x86/ptrace_syscall.c294
-rw-r--r--tools/testing/selftests/x86/raw_syscall_helper_32.S46
-rw-r--r--tools/testing/selftests/x86/test_syscall_vdso.c401
-rw-r--r--tools/testing/selftests/x86/thunks_32.S55
-rw-r--r--tools/testing/selftests/x86/unwind_vdso.c211
6 files changed, 1011 insertions, 2 deletions
diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index 29089b24d18b..389701f59940 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -4,8 +4,8 @@ include ../lib.mk
.PHONY: all all_32 all_64 warn_32bit_failure clean
-TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs ldt_gdt syscall_nt
-TARGETS_C_32BIT_ONLY := entry_from_vm86 syscall_arg_fault sigreturn
+TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs ldt_gdt syscall_nt ptrace_syscall
+TARGETS_C_32BIT_ONLY := entry_from_vm86 syscall_arg_fault sigreturn test_syscall_vdso unwind_vdso
TARGETS_C_32BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_32BIT_ONLY)
BINARIES_32 := $(TARGETS_C_32BIT_ALL:%=%_32)
@@ -60,3 +60,5 @@ endif
# Some tests have additional dependencies.
sysret_ss_attrs_64: thunks.S
+ptrace_syscall_32: raw_syscall_helper_32.S
+test_syscall_vdso_32: thunks_32.S
diff --git a/tools/testing/selftests/x86/ptrace_syscall.c b/tools/testing/selftests/x86/ptrace_syscall.c
new file mode 100644
index 000000000000..5105b49cd8aa
--- /dev/null
+++ b/tools/testing/selftests/x86/ptrace_syscall.c
@@ -0,0 +1,294 @@
+#define _GNU_SOURCE
+
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/syscall.h>
+#include <sys/user.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <err.h>
+#include <string.h>
+#include <asm/ptrace-abi.h>
+#include <sys/auxv.h>
+
+/* Bitness-agnostic defines for user_regs_struct fields. */
+#ifdef __x86_64__
+# define user_syscall_nr orig_rax
+# define user_arg0 rdi
+# define user_arg1 rsi
+# define user_arg2 rdx
+# define user_arg3 r10
+# define user_arg4 r8
+# define user_arg5 r9
+# define user_ip rip
+# define user_ax rax
+#else
+# define user_syscall_nr orig_eax
+# define user_arg0 ebx
+# define user_arg1 ecx
+# define user_arg2 edx
+# define user_arg3 esi
+# define user_arg4 edi
+# define user_arg5 ebp
+# define user_ip eip
+# define user_ax eax
+#endif
+
+static int nerrs = 0;
+
+struct syscall_args32 {
+ uint32_t nr, arg0, arg1, arg2, arg3, arg4, arg5;
+};
+
+#ifdef __i386__
+extern void sys32_helper(struct syscall_args32 *, void *);
+extern void int80_and_ret(void);
+#endif
+
+/*
+ * Helper to invoke int80 with controlled regs and capture the final regs.
+ */
+static void do_full_int80(struct syscall_args32 *args)
+{
+#ifdef __x86_64__
+ register unsigned long bp asm("bp") = args->arg5;
+ asm volatile ("int $0x80"
+ : "+a" (args->nr),
+ "+b" (args->arg0), "+c" (args->arg1), "+d" (args->arg2),
+ "+S" (args->arg3), "+D" (args->arg4), "+r" (bp));
+ args->arg5 = bp;
+#else
+ sys32_helper(args, int80_and_ret);
+#endif
+}
+
+#ifdef __i386__
+static void (*vsyscall32)(void);
+
+/*
+ * Nasty helper to invoke AT_SYSINFO (i.e. __kernel_vsyscall) with
+ * controlled regs and capture the final regs. This is so nasty that it
+ * crashes my copy of gdb :)
+ */
+static void do_full_vsyscall32(struct syscall_args32 *args)
+{
+ sys32_helper(args, vsyscall32);
+}
+#endif
+
+static siginfo_t wait_trap(pid_t chld)
+{
+ siginfo_t si;
+ if (waitid(P_PID, chld, &si, WEXITED|WSTOPPED) != 0)
+ err(1, "waitid");
+ if (si.si_pid != chld)
+ errx(1, "got unexpected pid in event\n");
+ if (si.si_code != CLD_TRAPPED)
+ errx(1, "got unexpected event type %d\n", si.si_code);
+ return si;
+}
+
+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");
+}
+
+static void clearhandler(int sig)
+{
+ struct sigaction sa;
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_handler = SIG_DFL;
+ sigemptyset(&sa.sa_mask);
+ if (sigaction(sig, &sa, 0))
+ err(1, "sigaction");
+}
+
+#ifdef __x86_64__
+# define REG_BP REG_RBP
+#else
+# define REG_BP REG_EBP
+#endif
+
+static void empty_handler(int sig, siginfo_t *si, void *ctx_void)
+{
+}
+
+static void test_sys32_regs(void (*do_syscall)(struct syscall_args32 *))
+{
+ struct syscall_args32 args = {
+ .nr = 224, /* gettid */
+ .arg0 = 10, .arg1 = 11, .arg2 = 12,
+ .arg3 = 13, .arg4 = 14, .arg5 = 15,
+ };
+
+ do_syscall(&args);
+
+ if (args.nr != getpid() ||
+ args.arg0 != 10 || args.arg1 != 11 || args.arg2 != 12 ||
+ args.arg3 != 13 || args.arg4 != 14 || args.arg5 != 15) {
+ printf("[FAIL]\tgetpid() failed to preseve regs\n");
+ nerrs++;
+ } else {
+ printf("[OK]\tgetpid() preserves regs\n");
+ }
+
+ sethandler(SIGUSR1, empty_handler, 0);
+
+ args.nr = 37; /* kill */
+ args.arg0 = getpid();
+ args.arg1 = SIGUSR1;
+ do_syscall(&args);
+ if (args.nr != 0 ||
+ args.arg0 != getpid() || args.arg1 != SIGUSR1 || args.arg2 != 12 ||
+ args.arg3 != 13 || args.arg4 != 14 || args.arg5 != 15) {
+ printf("[FAIL]\tkill(getpid(), SIGUSR1) failed to preseve regs\n");
+ nerrs++;
+ } else {
+ printf("[OK]\tkill(getpid(), SIGUSR1) preserves regs\n");
+ }
+ clearhandler(SIGUSR1);
+}
+
+static void test_ptrace_syscall_restart(void)
+{
+ printf("[RUN]\tptrace-induced syscall restart\n");
+ pid_t chld = fork();
+ if (chld < 0)
+ err(1, "fork");
+
+ if (chld == 0) {
+ if (ptrace(PTRACE_TRACEME, 0, 0, 0) != 0)
+ err(1, "PTRACE_TRACEME");
+
+ printf("\tChild will make one syscall\n");
+ raise(SIGSTOP);
+
+ syscall(SYS_gettid, 10, 11, 12, 13, 14, 15);
+ _exit(0);
+ }
+
+ int status;
+
+ /* Wait for SIGSTOP. */
+ if (waitpid(chld, &status, 0) != chld || !WIFSTOPPED(status))
+ err(1, "waitpid");
+
+ struct user_regs_struct regs;
+
+ printf("[RUN]\tSYSEMU\n");
+ if (ptrace(PTRACE_SYSEMU, chld, 0, 0) != 0)
+ err(1, "PTRACE_SYSCALL");
+ wait_trap(chld);
+
+ if (ptrace(PTRACE_GETREGS, chld, 0, &regs) != 0)
+ err(1, "PTRACE_GETREGS");
+
+ if (regs.user_syscall_nr != SYS_gettid ||
+ regs.user_arg0 != 10 || regs.user_arg1 != 11 ||
+ regs.user_arg2 != 12 || regs.user_arg3 != 13 ||
+ regs.user_arg4 != 14 || regs.user_arg5 != 15) {
+ printf("[FAIL]\tInitial args are wrong (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n", (unsigned long)regs.user_syscall_nr, (unsigned long)regs.user_arg0, (unsigned long)regs.user_arg1, (unsigned long)regs.user_arg2, (unsigned long)regs.user_arg3, (unsigned long)regs.user_arg4, (unsigned long)regs.user_arg5);
+ nerrs++;
+ } else {
+ printf("[OK]\tInitial nr and args are correct\n");
+ }
+
+ printf("[RUN]\tRestart the syscall (ip = 0x%lx)\n",
+ (unsigned long)regs.user_ip);
+
+ /*
+ * This does exactly what it appears to do if syscall is int80 or
+ * SYSCALL64. For SYSCALL32 or SYSENTER, though, this is highly
+ * magical. It needs to work so that ptrace and syscall restart
+ * work as expected.
+ */
+ regs.user_ax = regs.user_syscall_nr;
+ regs.user_ip -= 2;
+ if (ptrace(PTRACE_SETREGS, chld, 0, &regs) != 0)
+ err(1, "PTRACE_SETREGS");
+
+ if (ptrace(PTRACE_SYSEMU, chld, 0, 0) != 0)
+ err(1, "PTRACE_SYSCALL");
+ wait_trap(chld);
+
+ if (ptrace(PTRACE_GETREGS, chld, 0, &regs) != 0)
+ err(1, "PTRACE_GETREGS");
+
+ if (regs.user_syscall_nr != SYS_gettid ||
+ regs.user_arg0 != 10 || regs.user_arg1 != 11 ||
+ regs.user_arg2 != 12 || regs.user_arg3 != 13 ||
+ regs.user_arg4 != 14 || regs.user_arg5 != 15) {
+ printf("[FAIL]\tRestart nr or args are wrong (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n", (unsigned long)regs.user_syscall_nr, (unsigned long)regs.user_arg0, (unsigned long)regs.user_arg1, (unsigned long)regs.user_arg2, (unsigned long)regs.user_arg3, (unsigned long)regs.user_arg4, (unsigned long)regs.user_arg5);
+ nerrs++;
+ } else {
+ printf("[OK]\tRestarted nr and args are correct\n");
+ }
+
+ printf("[RUN]\tChange nr and args and restart the syscall (ip = 0x%lx)\n",
+ (unsigned long)regs.user_ip);
+
+ regs.user_ax = SYS_getpid;
+ regs.user_arg0 = 20;
+ regs.user_arg1 = 21;
+ regs.user_arg2 = 22;
+ regs.user_arg3 = 23;
+ regs.user_arg4 = 24;
+ regs.user_arg5 = 25;
+ regs.user_ip -= 2;
+
+ if (ptrace(PTRACE_SETREGS, chld, 0, &regs) != 0)
+ err(1, "PTRACE_SETREGS");
+
+ if (ptrace(PTRACE_SYSEMU, chld, 0, 0) != 0)
+ err(1, "PTRACE_SYSCALL");
+ wait_trap(chld);
+
+ if (ptrace(PTRACE_GETREGS, chld, 0, &regs) != 0)
+ err(1, "PTRACE_GETREGS");
+
+ if (regs.user_syscall_nr != SYS_getpid ||
+ regs.user_arg0 != 20 || regs.user_arg1 != 21 || regs.user_arg2 != 22 ||
+ regs.user_arg3 != 23 || regs.user_arg4 != 24 || regs.user_arg5 != 25) {
+ printf("[FAIL]\tRestart nr or args are wrong (nr=%lu, args=%lu %lu %lu %lu %lu %lu)\n", (unsigned long)regs.user_syscall_nr, (unsigned long)regs.user_arg0, (unsigned long)regs.user_arg1, (unsigned long)regs.user_arg2, (unsigned long)regs.user_arg3, (unsigned long)regs.user_arg4, (unsigned long)regs.user_arg5);
+ nerrs++;
+ } else {
+ printf("[OK]\tReplacement nr and args are correct\n");
+ }
+
+ if (ptrace(PTRACE_CONT, chld, 0, 0) != 0)
+ err(1, "PTRACE_CONT");
+ if (waitpid(chld, &status, 0) != chld)
+ err(1, "waitpid");
+ if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+ printf("[FAIL]\tChild failed\n");
+ nerrs++;
+ } else {
+ printf("[OK]\tChild exited cleanly\n");
+ }
+}
+
+int main()
+{
+ printf("[RUN]\tCheck int80 return regs\n");
+ test_sys32_regs(do_full_int80);
+
+#if defined(__i386__) && (!defined(__GLIBC__) || __GLIBC__ > 2 || __GLIBC_MINOR__ >= 16)
+ vsyscall32 = (void *)getauxval(AT_SYSINFO);
+ printf("[RUN]\tCheck AT_SYSINFO return regs\n");
+ test_sys32_regs(do_full_vsyscall32);
+#endif
+
+ test_ptrace_syscall_restart();
+
+ return 0;
+}
diff --git a/tools/testing/selftests/x86/raw_syscall_helper_32.S b/tools/testing/selftests/x86/raw_syscall_helper_32.S
new file mode 100644
index 000000000000..534e71e35c6a
--- /dev/null
+++ b/tools/testing/selftests/x86/raw_syscall_helper_32.S
@@ -0,0 +1,46 @@
+.global sys32_helper
+sys32_helper:
+ /* Args: syscall_args_32*, function pointer */
+ pushl %ebp
+ pushl %ebx
+ pushl %esi
+ pushl %edi
+ movl 5*4(%esp), %eax /* pointer to args struct */
+
+ movl 1*4(%eax), %ebx
+ movl 2*4(%eax), %ecx
+ movl 3*4(%eax), %edx
+ movl 4*4(%eax), %esi
+ movl 5*4(%eax), %edi
+ movl 6*4(%eax), %ebp
+ movl 0*4(%eax), %eax
+
+ call *(6*4)(%esp) /* Do the syscall */
+
+ /* Now we need to recover without losing any reg values */
+ pushl %eax
+ movl 6*4(%esp), %eax
+ popl 0*4(%eax)
+ movl %ebx, 1*4(%eax)
+ movl %ecx, 2*4(%eax)
+ movl %edx, 3*4(%eax)
+ movl %esi, 4*4(%eax)
+ movl %edi, 5*4(%eax)
+ movl %ebp, 6*4(%eax)
+
+ popl %edi
+ popl %esi
+ popl %ebx
+ popl %ebp
+ ret
+
+ .type sys32_helper, @function
+ .size sys32_helper, .-sys32_helper
+
+.global int80_and_ret
+int80_and_ret:
+ int $0x80
+ ret
+
+ .type int80_and_ret, @function
+ .size int80_and_ret, .-int80_and_ret
diff --git a/tools/testing/selftests/x86/test_syscall_vdso.c b/tools/testing/selftests/x86/test_syscall_vdso.c
new file mode 100644
index 000000000000..40370354d4c1
--- /dev/null
+++ b/tools/testing/selftests/x86/test_syscall_vdso.c
@@ -0,0 +1,401 @@
+/*
+ * 32-bit syscall ABI conformance test.
+ *
+ * Copyright (c) 2015 Denys Vlasenko
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+/*
+ * Can be built statically:
+ * gcc -Os -Wall -static -m32 test_syscall_vdso.c thunks_32.S
+ */
+#undef _GNU_SOURCE
+#define _GNU_SOURCE 1
+#undef __USE_GNU
+#define __USE_GNU 1
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/select.h>
+#include <sys/time.h>
+#include <elf.h>
+#include <sys/ptrace.h>
+#include <sys/wait.h>
+
+#if !defined(__i386__)
+int main(int argc, char **argv, char **envp)
+{
+ printf("[SKIP]\tNot a 32-bit x86 userspace\n");
+ return 0;
+}
+#else
+
+long syscall_addr;
+long get_syscall(char **envp)
+{
+ Elf32_auxv_t *auxv;
+ while (*envp++ != NULL)
+ continue;
+ for (auxv = (void *)envp; auxv->a_type != AT_NULL; auxv++)
+ if (auxv->a_type == AT_SYSINFO)
+ return auxv->a_un.a_val;
+ printf("[WARN]\tAT_SYSINFO not supplied\n");
+ return 0;
+}
+
+asm (
+ " .pushsection .text\n"
+ " .global int80\n"
+ "int80:\n"
+ " int $0x80\n"
+ " ret\n"
+ " .popsection\n"
+);
+extern char int80;
+
+struct regs64 {
+ uint64_t rax, rbx, rcx, rdx;
+ uint64_t rsi, rdi, rbp, rsp;
+ uint64_t r8, r9, r10, r11;
+ uint64_t r12, r13, r14, r15;
+};
+struct regs64 regs64;
+int kernel_is_64bit;
+
+asm (
+ " .pushsection .text\n"
+ " .code64\n"
+ "get_regs64:\n"
+ " push %rax\n"
+ " mov $regs64, %eax\n"
+ " pop 0*8(%rax)\n"
+ " movq %rbx, 1*8(%rax)\n"
+ " movq %rcx, 2*8(%rax)\n"
+ " movq %rdx, 3*8(%rax)\n"
+ " movq %rsi, 4*8(%rax)\n"
+ " movq %rdi, 5*8(%rax)\n"
+ " movq %rbp, 6*8(%rax)\n"
+ " movq %rsp, 7*8(%rax)\n"
+ " movq %r8, 8*8(%rax)\n"
+ " movq %r9, 9*8(%rax)\n"
+ " movq %r10, 10*8(%rax)\n"
+ " movq %r11, 11*8(%rax)\n"
+ " movq %r12, 12*8(%rax)\n"
+ " movq %r13, 13*8(%rax)\n"
+ " movq %r14, 14*8(%rax)\n"
+ " movq %r15, 15*8(%rax)\n"
+ " ret\n"
+ "poison_regs64:\n"
+ " movq $0x7f7f7f7f, %r8\n"
+ " shl $32, %r8\n"
+ " orq $0x7f7f7f7f, %r8\n"
+ " movq %r8, %r9\n"
+ " movq %r8, %r10\n"
+ " movq %r8, %r11\n"
+ " movq %r8, %r12\n"
+ " movq %r8, %r13\n"
+ " movq %r8, %r14\n"
+ " movq %r8, %r15\n"
+ " ret\n"
+ " .code32\n"
+ " .popsection\n"
+);
+extern void get_regs64(void);
+extern void poison_regs64(void);
+extern unsigned long call64_from_32(void (*function)(void));
+void print_regs64(void)
+{
+ if (!kernel_is_64bit)
+ return;
+ printf("ax:%016llx bx:%016llx cx:%016llx dx:%016llx\n", regs64.rax, regs64.rbx, regs64.rcx, regs64.rdx);
+ printf("si:%016llx di:%016llx bp:%016llx sp:%016llx\n", regs64.rsi, regs64.rdi, regs64.rbp, regs64.rsp);
+ printf(" 8:%016llx 9:%016llx 10:%016llx 11:%016llx\n", regs64.r8 , regs64.r9 , regs64.r10, regs64.r11);
+ printf("12:%016llx 13:%016llx 14:%016llx 15:%016llx\n", regs64.r12, regs64.r13, regs64.r14, regs64.r15);
+}
+
+int check_regs64(void)
+{
+ int err = 0;
+ int num = 8;
+ uint64_t *r64 = &regs64.r8;
+
+ if (!kernel_is_64bit)
+ return 0;
+
+ do {
+ if (*r64 == 0x7f7f7f7f7f7f7f7fULL)
+ continue; /* register did not change */
+ if (syscall_addr != (long)&int80) {
+ /*
+ * Non-INT80 syscall entrypoints are allowed to clobber R8+ regs:
+ * either clear them to 0, or for R11, load EFLAGS.
+ */
+ if (*r64 == 0)
+ continue;
+ if (num == 11) {
+ printf("[NOTE]\tR11 has changed:%016llx - assuming clobbered by SYSRET insn\n", *r64);
+ continue;
+ }
+ } else {
+ /* INT80 syscall entrypoint can be used by
+ * 64-bit programs too, unlike SYSCALL/SYSENTER.
+ * Therefore it must preserve R12+
+ * (they are callee-saved registers in 64-bit C ABI).
+ *
+ * This was probably historically not intended,
+ * but R8..11 are clobbered (cleared to 0).
+ * IOW: they are the only registers which aren't
+ * preserved across INT80 syscall.
+ */
+ if (*r64 == 0 && num <= 11)
+ continue;
+ }
+ printf("[FAIL]\tR%d has changed:%016llx\n", num, *r64);
+ err++;
+ } while (r64++, ++num < 16);
+
+ if (!err)
+ printf("[OK]\tR8..R15 did not leak kernel data\n");
+ return err;
+}
+
+int nfds;
+fd_set rfds;
+fd_set wfds;
+fd_set efds;
+struct timespec timeout;
+sigset_t sigmask;
+struct {
+ sigset_t *sp;
+ int sz;
+} sigmask_desc;
+
+void prep_args()
+{
+ nfds = 42;
+ FD_ZERO(&rfds);
+ FD_ZERO(&wfds);
+ FD_ZERO(&efds);
+ FD_SET(0, &rfds);
+ FD_SET(1, &wfds);
+ FD_SET(2, &efds);
+ timeout.tv_sec = 0;
+ timeout.tv_nsec = 123;
+ sigemptyset(&sigmask);
+ sigaddset(&sigmask, SIGINT);
+ sigaddset(&sigmask, SIGUSR2);
+ sigaddset(&sigmask, SIGRTMAX);
+ sigmask_desc.sp = &sigmask;
+ sigmask_desc.sz = 8; /* bytes */
+}
+
+static void print_flags(const char *name, unsigned long r)
+{
+ static const char *bitarray[] = {
+ "\n" ,"c\n" ,/* Carry Flag */
+ "0 " ,"1 " ,/* Bit 1 - always on */
+ "" ,"p " ,/* Parity Flag */
+ "0 " ,"3? " ,
+ "" ,"a " ,/* Auxiliary carry Flag */
+ "0 " ,"5? " ,
+ "" ,"z " ,/* Zero Flag */
+ "" ,"s " ,/* Sign Flag */
+ "" ,"t " ,/* Trap Flag */
+ "" ,"i " ,/* Interrupt Flag */
+ "" ,"d " ,/* Direction Flag */
+ "" ,"o " ,/* Overflow Flag */
+ "0 " ,"1 " ,/* I/O Privilege Level (2 bits) */
+ "0" ,"1" ,/* I/O Privilege Level (2 bits) */
+ "" ,"n " ,/* Nested Task */
+ "0 " ,"15? ",
+ "" ,"r " ,/* Resume Flag */
+ "" ,"v " ,/* Virtual Mode */
+ "" ,"ac " ,/* Alignment Check/Access Control */
+ "" ,"vif ",/* Virtual Interrupt Flag */
+ "" ,"vip ",/* Virtual Interrupt Pending */
+ "" ,"id " ,/* CPUID detection */
+ NULL
+ };
+ const char **bitstr;
+ int bit;
+
+ printf("%s=%016lx ", name, r);
+ bitstr = bitarray + 42;
+ bit = 21;
+ if ((r >> 22) != 0)
+ printf("(extra bits are set) ");
+ do {
+ if (bitstr[(r >> bit) & 1][0])
+ fputs(bitstr[(r >> bit) & 1], stdout);
+ bitstr -= 2;
+ bit--;
+ } while (bit >= 0);
+}
+
+int run_syscall(void)
+{
+ long flags, bad_arg;
+
+ prep_args();
+
+ if (kernel_is_64bit)
+ call64_from_32(poison_regs64);
+ /*print_regs64();*/
+
+ asm("\n"
+ /* Try 6-arg syscall: pselect. It should return quickly */
+ " push %%ebp\n"
+ " mov $308, %%eax\n" /* PSELECT */
+ " mov nfds, %%ebx\n" /* ebx arg1 */
+ " mov $rfds, %%ecx\n" /* ecx arg2 */
+ " mov $wfds, %%edx\n" /* edx arg3 */
+ " mov $efds, %%esi\n" /* esi arg4 */
+ " mov $timeout, %%edi\n" /* edi arg5 */
+ " mov $sigmask_desc, %%ebp\n" /* %ebp arg6 */
+ " push $0x200ed7\n" /* set almost all flags */
+ " popf\n" /* except TF, IOPL, NT, RF, VM, AC, VIF, VIP */
+ " call *syscall_addr\n"
+ /* Check that registers are not clobbered */
+ " pushf\n"
+ " pop %%eax\n"
+ " cld\n"
+ " cmp nfds, %%ebx\n" /* ebx arg1 */
+ " mov $1, %%ebx\n"
+ " jne 1f\n"
+ " cmp $rfds, %%ecx\n" /* ecx arg2 */
+ " mov $2, %%ebx\n"
+ " jne 1f\n"
+ " cmp $wfds, %%edx\n" /* edx arg3 */
+ " mov $3, %%ebx\n"
+ " jne 1f\n"
+ " cmp $efds, %%esi\n" /* esi arg4 */
+ " mov $4, %%ebx\n"
+ " jne 1f\n"
+ " cmp $timeout, %%edi\n" /* edi arg5 */
+ " mov $5, %%ebx\n"
+ " jne 1f\n"
+ " cmpl $sigmask_desc, %%ebp\n" /* %ebp arg6 */
+ " mov $6, %%ebx\n"
+ " jne 1f\n"
+ " mov $0, %%ebx\n"
+ "1:\n"
+ " pop %%ebp\n"
+ : "=a" (flags), "=b" (bad_arg)
+ :
+ : "cx", "dx", "si", "di"
+ );
+
+ if (kernel_is_64bit) {
+ memset(&regs64, 0x77, sizeof(regs64));
+ call64_from_32(get_regs64);
+ /*print_regs64();*/
+ }
+
+ /*
+ * On paravirt kernels, flags are not preserved across syscalls.
+ * Thus, we do not consider it a bug if some are changed.
+ * We just show ones which do.
+ */
+ if ((0x200ed7 ^ flags) != 0) {
+ print_flags("[WARN]\tFlags before", 0x200ed7);
+ print_flags("[WARN]\tFlags after", flags);
+ print_flags("[WARN]\tFlags change", (0x200ed7 ^ flags));
+ }
+
+ if (bad_arg) {
+ printf("[FAIL]\targ#%ld clobbered\n", bad_arg);
+ return 1;
+ }
+ printf("[OK]\tArguments are preserved across syscall\n");
+
+ return check_regs64();
+}
+
+int run_syscall_twice()
+{
+ int exitcode = 0;
+ long sv;
+
+ if (syscall_addr) {
+ printf("[RUN]\tExecuting 6-argument 32-bit syscall via VDSO\n");
+ exitcode = run_syscall();
+ }
+ sv = syscall_addr;
+ syscall_addr = (long)&int80;
+ printf("[RUN]\tExecuting 6-argument 32-bit syscall via INT 80\n");
+ exitcode += run_syscall();
+ syscall_addr = sv;
+ return exitcode;
+}
+
+void ptrace_me()
+{
+ pid_t pid;
+
+ fflush(NULL);
+ pid = fork();
+ if (pid < 0)
+ exit(1);
+ if (pid == 0) {
+ /* child */
+ if (ptrace(PTRACE_TRACEME, 0L, 0L, 0L) != 0)
+ exit(0);
+ raise(SIGSTOP);
+ return;
+ }
+ /* parent */
+ printf("[RUN]\tRunning tests under ptrace\n");
+ while (1) {
+ int status;
+ pid = waitpid(-1, &status, __WALL);
+ if (WIFEXITED(status))
+ exit(WEXITSTATUS(status));
+ if (WIFSIGNALED(status))
+ exit(WTERMSIG(status));
+ if (pid <= 0 || !WIFSTOPPED(status)) /* paranoia */
+ exit(255);
+ /*
+ * Note: we do not inject sig = WSTOPSIG(status).
+ * We probably should, but careful: do not inject SIGTRAP
+ * generated by syscall entry/exit stops.
+ * That kills the child.
+ */
+ ptrace(PTRACE_SYSCALL, pid, 0L, 0L /*sig*/);
+ }
+}
+
+int main(int argc, char **argv, char **envp)
+{
+ int exitcode = 0;
+ int cs;
+
+ asm("\n"
+ " movl %%cs, %%eax\n"
+ : "=a" (cs)
+ );
+ kernel_is_64bit = (cs == 0x23);
+ if (!kernel_is_64bit)
+ printf("[NOTE]\tNot a 64-bit kernel, won't test R8..R15 leaks\n");
+
+ /* This only works for non-static builds:
+ * syscall_addr = dlsym(dlopen("linux-gate.so.1", RTLD_NOW), "__kernel_vsyscall");
+ */
+ syscall_addr = get_syscall(envp);
+
+ exitcode += run_syscall_twice();
+ ptrace_me();
+ exitcode += run_syscall_twice();
+
+ return exitcode;
+}
+#endif
diff --git a/tools/testing/selftests/x86/thunks_32.S b/tools/testing/selftests/x86/thunks_32.S
new file mode 100644
index 000000000000..29b644bb9f2f
--- /dev/null
+++ b/tools/testing/selftests/x86/thunks_32.S
@@ -0,0 +1,55 @@
+/*
+ * thunks_32.S - assembly helpers for mixed-bitness code
+ * Copyright (c) 2015 Denys Vlasenko
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * These are little helpers that make it easier to switch bitness on
+ * the fly.
+ */
+
+ .text
+ .code32
+
+ .global call64_from_32
+ .type call32_from_64, @function
+
+ // 4(%esp): function to call
+call64_from_32:
+ // Fetch function address
+ mov 4(%esp), %eax
+
+ // Save registers which are callee-clobbered by 64-bit ABI
+ push %ecx
+ push %edx
+ push %esi
+ push %edi
+
+ // Switch to long mode
+ jmp $0x33,$1f
+1: .code64
+
+ // Call the function
+ call *%rax
+
+ // Switch to compatibility mode
+ push $0x23 /* USER32_CS */
+ .code32; push $1f; .code64 /* hack: can't have X86_64_32S relocation in 32-bit ELF */
+ lretq
+1: .code32
+
+ pop %edi
+ pop %esi
+ pop %edx
+ pop %ecx
+
+ ret
+
+.size call64_from_32, .-call64_from_32
diff --git a/tools/testing/selftests/x86/unwind_vdso.c b/tools/testing/selftests/x86/unwind_vdso.c
new file mode 100644
index 000000000000..00a26a82fa98
--- /dev/null
+++ b/tools/testing/selftests/x86/unwind_vdso.c
@@ -0,0 +1,211 @@
+/*
+ * unwind_vdso.c - tests unwind info for AT_SYSINFO in the vDSO
+ * Copyright (c) 2014-2015 Andrew Lutomirski
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * This tests __kernel_vsyscall's unwind info.
+ */
+
+#define _GNU_SOURCE
+
+#include <features.h>
+#include <stdio.h>
+
+#if defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16
+
+int main()
+{
+ /* We need getauxval(). */
+ printf("[SKIP]\tGLIBC before 2.16 cannot compile this test\n");
+ return 0;
+}
+
+#else
+
+#include <sys/time.h>
+#include <stdlib.h>
+#include <syscall.h>
+#include <unistd.h>
+#include <string.h>
+#include <inttypes.h>
+#include <sys/mman.h>
+#include <signal.h>
+#include <sys/ucontext.h>
+#include <err.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include <sys/ptrace.h>
+#include <sys/user.h>
+#include <sys/ucontext.h>
+#include <link.h>
+#include <sys/auxv.h>
+#include <dlfcn.h>
+#include <unwind.h>
+
+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");
+}
+
+#ifdef __x86_64__
+# define WIDTH "q"
+#else
+# define WIDTH "l"
+#endif
+
+static unsigned long get_eflags(void)
+{
+ unsigned long eflags;
+ asm volatile ("pushf" WIDTH "\n\tpop" WIDTH " %0" : "=rm" (eflags));
+ return eflags;
+}
+
+static void set_eflags(unsigned long eflags)
+{
+ asm volatile ("push" WIDTH " %0\n\tpopf" WIDTH
+ : : "rm" (eflags) : "flags");
+}
+
+#define X86_EFLAGS_TF (1UL << 8)
+
+static volatile sig_atomic_t nerrs;
+static unsigned long sysinfo;
+static bool got_sysinfo = false;
+static unsigned long return_address;
+
+struct unwind_state {
+ unsigned long ip; /* trap source */
+ int depth; /* -1 until we hit the trap source */
+};
+
+_Unwind_Reason_Code trace_fn(struct _Unwind_Context * ctx, void *opaque)
+{
+ struct unwind_state *state = opaque;
+ unsigned long ip = _Unwind_GetIP(ctx);
+
+ if (state->depth == -1) {
+ if (ip == state->ip)
+ state->depth = 0;
+ else
+ return _URC_NO_REASON; /* Not there yet */
+ }
+ printf("\t 0x%lx\n", ip);
+
+ if (ip == return_address) {
+ /* Here we are. */
+ unsigned long eax = _Unwind_GetGR(ctx, 0);
+ unsigned long ecx = _Unwind_GetGR(ctx, 1);
+ unsigned long edx = _Unwind_GetGR(ctx, 2);
+ unsigned long ebx = _Unwind_GetGR(ctx, 3);
+ unsigned long ebp = _Unwind_GetGR(ctx, 5);
+ unsigned long esi = _Unwind_GetGR(ctx, 6);
+ unsigned long edi = _Unwind_GetGR(ctx, 7);
+ bool ok = (eax == SYS_getpid || eax == getpid()) &&
+ ebx == 1 && ecx == 2 && edx == 3 &&
+ esi == 4 && edi == 5 && ebp == 6;
+
+ if (!ok)
+ nerrs++;
+ printf("[%s]\t NR = %ld, args = %ld, %ld, %ld, %ld, %ld, %ld\n",
+ (ok ? "OK" : "FAIL"),
+ eax, ebx, ecx, edx, esi, edi, ebp);
+
+ return _URC_NORMAL_STOP;
+ } else {
+ state->depth++;
+ return _URC_NO_REASON;
+ }
+}
+
+static void sigtrap(int sig, siginfo_t *info, void *ctx_void)
+{
+ ucontext_t *ctx = (ucontext_t *)ctx_void;
+ struct unwind_state state;
+ unsigned long ip = ctx->uc_mcontext.gregs[REG_EIP];
+
+ if (!got_sysinfo && ip == sysinfo) {
+ got_sysinfo = true;
+
+ /* Find the return address. */
+ return_address = *(unsigned long *)(unsigned long)ctx->uc_mcontext.gregs[REG_ESP];
+
+ printf("\tIn vsyscall at 0x%lx, returning to 0x%lx\n",
+ ip, return_address);
+ }
+
+ if (!got_sysinfo)
+ return; /* Not there yet */
+
+ if (ip == return_address) {
+ ctx->uc_mcontext.gregs[REG_EFL] &= ~X86_EFLAGS_TF;
+ printf("\tVsyscall is done\n");
+ return;
+ }
+
+ printf("\tSIGTRAP at 0x%lx\n", ip);
+
+ state.ip = ip;
+ state.depth = -1;
+ _Unwind_Backtrace(trace_fn, &state);
+}
+
+int main()
+{
+ sysinfo = getauxval(AT_SYSINFO);
+ printf("\tAT_SYSINFO is 0x%lx\n", sysinfo);
+
+ Dl_info info;
+ if (!dladdr((void *)sysinfo, &info)) {
+ printf("[WARN]\tdladdr failed on AT_SYSINFO\n");
+ } else {
+ printf("[OK]\tAT_SYSINFO maps to %s, loaded at 0x%p\n",
+ info.dli_fname, info.dli_fbase);
+ }
+
+ sethandler(SIGTRAP, sigtrap, 0);
+
+ syscall(SYS_getpid); /* Force symbol binding without TF set. */
+ printf("[RUN]\tSet TF and check a fast syscall\n");
+ set_eflags(get_eflags() | X86_EFLAGS_TF);
+ syscall(SYS_getpid, 1, 2, 3, 4, 5, 6);
+ if (!got_sysinfo) {
+ set_eflags(get_eflags() & ~X86_EFLAGS_TF);
+
+ /*
+ * The most likely cause of this is that you're on Debian or
+ * a Debian-based distro, you're missing libc6-i686, and you're
+ * affected by libc/19006 (https://sourceware.org/PR19006).
+ */
+ printf("[WARN]\tsyscall(2) didn't enter AT_SYSINFO\n");
+ }
+
+ if (get_eflags() & X86_EFLAGS_TF) {
+ printf("[FAIL]\tTF is still set\n");
+ nerrs++;
+ }
+
+ if (nerrs) {
+ printf("[FAIL]\tThere were errors\n");
+ return 1;
+ } else {
+ printf("[OK]\tAll is well\n");
+ return 0;
+ }
+}
+
+#endif /* New enough libc */