diff options
Diffstat (limited to 'tools/testing/selftests/x86')
| -rw-r--r-- | tools/testing/selftests/x86/ioperm.c | 16 | ||||
| -rw-r--r-- | tools/testing/selftests/x86/iopl.c | 129 | ||||
| -rw-r--r-- | tools/testing/selftests/x86/mov_ss_trap.c | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/x86/sigreturn.c | 13 | ||||
| -rw-r--r-- | tools/testing/selftests/x86/single_step_syscall.c | 94 |
5 files changed, 233 insertions, 22 deletions
diff --git a/tools/testing/selftests/x86/ioperm.c b/tools/testing/selftests/x86/ioperm.c index 01de41c1b725..57ec5e99edb9 100644 --- a/tools/testing/selftests/x86/ioperm.c +++ b/tools/testing/selftests/x86/ioperm.c @@ -131,6 +131,17 @@ int main(void) printf("[RUN]\tchild: check that we inherited permissions\n"); expect_ok(0x80); expect_gp(0xed); + printf("[RUN]\tchild: Extend permissions to 0x81\n"); + if (ioperm(0x81, 1, 1) != 0) { + printf("[FAIL]\tioperm(0x81, 1, 1) failed (%d)", errno); + return 1; + } + printf("[RUN]\tchild: Drop permissions to 0x80\n"); + if (ioperm(0x80, 1, 0) != 0) { + printf("[FAIL]\tioperm(0x80, 1, 0) failed (%d)", errno); + return 1; + } + expect_gp(0x80); return 0; } else { int status; @@ -146,8 +157,11 @@ int main(void) } } - /* Test the capability checks. */ + /* Verify that the child dropping 0x80 did not affect the parent */ + printf("\tVerify that unsharing the bitmap worked\n"); + expect_ok(0x80); + /* Test the capability checks. */ printf("\tDrop privileges\n"); if (setresuid(1, 1, 1) != 0) { printf("[WARN]\tDropping privileges failed\n"); diff --git a/tools/testing/selftests/x86/iopl.c b/tools/testing/selftests/x86/iopl.c index 6aa27f34644c..bab2f6e06b63 100644 --- a/tools/testing/selftests/x86/iopl.c +++ b/tools/testing/selftests/x86/iopl.c @@ -35,6 +35,16 @@ static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), } +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"); +} + static jmp_buf jmpbuf; static void sigsegv(int sig, siginfo_t *si, void *ctx_void) @@ -42,25 +52,128 @@ static void sigsegv(int sig, siginfo_t *si, void *ctx_void) siglongjmp(jmpbuf, 1); } +static bool try_outb(unsigned short port) +{ + sethandler(SIGSEGV, sigsegv, SA_RESETHAND); + if (sigsetjmp(jmpbuf, 1) != 0) { + return false; + } else { + asm volatile ("outb %%al, %w[port]" + : : [port] "Nd" (port), "a" (0)); + return true; + } + clearhandler(SIGSEGV); +} + +static void expect_ok_outb(unsigned short port) +{ + if (!try_outb(port)) { + printf("[FAIL]\toutb to 0x%02hx failed\n", port); + exit(1); + } + + printf("[OK]\toutb to 0x%02hx worked\n", port); +} + +static void expect_gp_outb(unsigned short port) +{ + if (try_outb(port)) { + printf("[FAIL]\toutb to 0x%02hx worked\n", port); + nerrs++; + } + + printf("[OK]\toutb to 0x%02hx failed\n", port); +} + +static bool try_cli(void) +{ + sethandler(SIGSEGV, sigsegv, SA_RESETHAND); + if (sigsetjmp(jmpbuf, 1) != 0) { + return false; + } else { + asm volatile ("cli"); + return true; + } + clearhandler(SIGSEGV); +} + +static bool try_sti(void) +{ + sethandler(SIGSEGV, sigsegv, SA_RESETHAND); + if (sigsetjmp(jmpbuf, 1) != 0) { + return false; + } else { + asm volatile ("sti"); + return true; + } + clearhandler(SIGSEGV); +} + +static void expect_gp_sti(void) +{ + if (try_sti()) { + printf("[FAIL]\tSTI worked\n"); + nerrs++; + } else { + printf("[OK]\tSTI faulted\n"); + } +} + +static void expect_gp_cli(void) +{ + if (try_cli()) { + printf("[FAIL]\tCLI worked\n"); + nerrs++; + } else { + printf("[OK]\tCLI faulted\n"); + } +} + int main(void) { cpu_set_t cpuset; + CPU_ZERO(&cpuset); CPU_SET(0, &cpuset); if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) err(1, "sched_setaffinity to CPU 0"); /* Probe for iopl support. Note that iopl(0) works even as nonroot. */ - if (iopl(3) != 0) { + switch(iopl(3)) { + case 0: + break; + case -ENOSYS: + printf("[OK]\tiopl() nor supported\n"); + return 0; + default: printf("[OK]\tiopl(3) failed (%d) -- try running as root\n", errno); return 0; } - /* Restore our original state prior to starting the test. */ + /* Make sure that CLI/STI are blocked even with IOPL level 3 */ + expect_gp_cli(); + expect_gp_sti(); + expect_ok_outb(0x80); + + /* Establish an I/O bitmap to test the restore */ + if (ioperm(0x80, 1, 1) != 0) + err(1, "ioperm(0x80, 1, 1) failed\n"); + + /* Restore our original state prior to starting the fork test. */ if (iopl(0) != 0) err(1, "iopl(0)"); + /* + * Verify that IOPL emulation is disabled and the I/O bitmap still + * works. + */ + expect_ok_outb(0x80); + expect_gp_outb(0xed); + /* Drop the I/O bitmap */ + if (ioperm(0x80, 1, 0) != 0) + err(1, "ioperm(0x80, 1, 0) failed\n"); + pid_t child = fork(); if (child == -1) err(1, "fork"); @@ -90,14 +203,9 @@ int main(void) printf("[RUN]\tparent: write to 0x80 (should fail)\n"); - sethandler(SIGSEGV, sigsegv, 0); - if (sigsetjmp(jmpbuf, 1) != 0) { - printf("[OK]\twrite was denied\n"); - } else { - asm volatile ("outb %%al, $0x80" : : "a" (0)); - printf("[FAIL]\twrite was allowed\n"); - nerrs++; - } + expect_gp_outb(0x80); + expect_gp_cli(); + expect_gp_sti(); /* Test the capability checks. */ printf("\tiopl(3)\n"); @@ -133,4 +241,3 @@ int main(void) done: return nerrs ? 1 : 0; } - diff --git a/tools/testing/selftests/x86/mov_ss_trap.c b/tools/testing/selftests/x86/mov_ss_trap.c index 3c3a022654f3..6da0ac3f0135 100644 --- a/tools/testing/selftests/x86/mov_ss_trap.c +++ b/tools/testing/selftests/x86/mov_ss_trap.c @@ -257,7 +257,8 @@ int main() err(1, "sigaltstack"); sethandler(SIGSEGV, handle_and_longjmp, SA_RESETHAND | SA_ONSTACK); nr = SYS_getpid; - asm volatile ("mov %[ss], %%ss; SYSENTER" : "+a" (nr) + /* Clear EBP first to make sure we segfault cleanly. */ + asm volatile ("xorl %%ebp, %%ebp; mov %[ss], %%ss; SYSENTER" : "+a" (nr) : [ss] "m" (ss) : "flags", "rcx" #ifdef __x86_64__ , "r11" diff --git a/tools/testing/selftests/x86/sigreturn.c b/tools/testing/selftests/x86/sigreturn.c index 3e49a7873f3e..57c4f67f16ef 100644 --- a/tools/testing/selftests/x86/sigreturn.c +++ b/tools/testing/selftests/x86/sigreturn.c @@ -451,6 +451,19 @@ static void sigusr1(int sig, siginfo_t *info, void *ctx_void) ctx->uc_mcontext.gregs[REG_SP] = (unsigned long)0x8badf00d5aadc0deULL; ctx->uc_mcontext.gregs[REG_CX] = 0; +#ifdef __i386__ + /* + * Make sure the kernel doesn't inadvertently use DS or ES-relative + * accesses in a region where user DS or ES is loaded. + * + * Skip this for 64-bit builds because long mode doesn't care about + * DS and ES and skipping it increases test coverage a little bit, + * since 64-bit kernels can still run the 32-bit build. + */ + ctx->uc_mcontext.gregs[REG_DS] = 0; + ctx->uc_mcontext.gregs[REG_ES] = 0; +#endif + memcpy(&requested_regs, &ctx->uc_mcontext.gregs, sizeof(gregset_t)); requested_regs[REG_CX] = *ssptr(ctx); /* The asm code does this. */ diff --git a/tools/testing/selftests/x86/single_step_syscall.c b/tools/testing/selftests/x86/single_step_syscall.c index 50ce6c3dd904..1063328e275c 100644 --- a/tools/testing/selftests/x86/single_step_syscall.c +++ b/tools/testing/selftests/x86/single_step_syscall.c @@ -43,7 +43,19 @@ static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), err(1, "sigaction"); } -static volatile sig_atomic_t sig_traps; +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"); +} + +static volatile sig_atomic_t sig_traps, sig_eflags; +sigjmp_buf jmpbuf; +static unsigned char altstack_data[SIGSTKSZ]; #ifdef __x86_64__ # define REG_IP REG_RIP @@ -90,6 +102,25 @@ static void sigtrap(int sig, siginfo_t *info, void *ctx_void) } } +static char const * const signames[] = { + [SIGSEGV] = "SIGSEGV", + [SIGBUS] = "SIBGUS", + [SIGTRAP] = "SIGTRAP", + [SIGILL] = "SIGILL", +}; + +static void print_and_longjmp(int sig, siginfo_t *si, void *ctx_void) +{ + ucontext_t *ctx = ctx_void; + + printf("\tGot %s with RIP=%lx, TF=%ld\n", signames[sig], + (unsigned long)ctx->uc_mcontext.gregs[REG_IP], + (unsigned long)ctx->uc_mcontext.gregs[REG_EFL] & X86_EFLAGS_TF); + + sig_eflags = (unsigned long)ctx->uc_mcontext.gregs[REG_EFL]; + siglongjmp(jmpbuf, 1); +} + static void check_result(void) { unsigned long new_eflags = get_eflags(); @@ -109,6 +140,22 @@ static void check_result(void) sig_traps = 0; } +static void fast_syscall_no_tf(void) +{ + sig_traps = 0; + printf("[RUN]\tFast syscall with TF cleared\n"); + fflush(stdout); /* Force a syscall */ + if (get_eflags() & X86_EFLAGS_TF) { + printf("[FAIL]\tTF is now set\n"); + exit(1); + } + if (sig_traps) { + printf("[FAIL]\tGot SIGTRAP\n"); + exit(1); + } + printf("[OK]\tNothing unexpected happened\n"); +} + int main() { #ifdef CAN_BUILD_32 @@ -163,17 +210,46 @@ int main() check_result(); /* Now make sure that another fast syscall doesn't set TF again. */ - printf("[RUN]\tFast syscall with TF cleared\n"); - fflush(stdout); /* Force a syscall */ - if (get_eflags() & X86_EFLAGS_TF) { - printf("[FAIL]\tTF is now set\n"); - exit(1); + fast_syscall_no_tf(); + + /* + * And do a forced SYSENTER to make sure that this works even if + * fast syscalls don't use SYSENTER. + * + * Invoking SYSENTER directly breaks all the rules. Just handle + * the SIGSEGV. + */ + if (sigsetjmp(jmpbuf, 1) == 0) { + unsigned long nr = SYS_getpid; + printf("[RUN]\tSet TF and check SYSENTER\n"); + stack_t stack = { + .ss_sp = altstack_data, + .ss_size = SIGSTKSZ, + }; + if (sigaltstack(&stack, NULL) != 0) + err(1, "sigaltstack"); + sethandler(SIGSEGV, print_and_longjmp, + SA_RESETHAND | SA_ONSTACK); + sethandler(SIGILL, print_and_longjmp, SA_RESETHAND); + set_eflags(get_eflags() | X86_EFLAGS_TF); + /* Clear EBP first to make sure we segfault cleanly. */ + asm volatile ("xorl %%ebp, %%ebp; SYSENTER" : "+a" (nr) :: "flags", "rcx" +#ifdef __x86_64__ + , "r11" +#endif + ); + + /* We're unreachable here. SYSENTER forgets RIP. */ } - if (sig_traps) { - printf("[FAIL]\tGot SIGTRAP\n"); + clearhandler(SIGSEGV); + clearhandler(SIGILL); + if (!(sig_eflags & X86_EFLAGS_TF)) { + printf("[FAIL]\tTF was cleared\n"); exit(1); } - printf("[OK]\tNothing unexpected happened\n"); + + /* Now make sure that another fast syscall doesn't set TF again. */ + fast_syscall_no_tf(); return 0; } |