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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/testing/selftests/x86/syscall_nt.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/x86/syscall_nt.c')
-rw-r--r-- | tools/testing/selftests/x86/syscall_nt.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/tools/testing/selftests/x86/syscall_nt.c b/tools/testing/selftests/x86/syscall_nt.c new file mode 100644 index 000000000..a108b80dd --- /dev/null +++ b/tools/testing/selftests/x86/syscall_nt.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * syscall_nt.c - checks syscalls with NT set + * Copyright (c) 2014-2015 Andrew Lutomirski + * + * Some obscure user-space code requires the ability to make system calls + * with FLAGS.NT set. Make sure it works. + */ + +#include <stdio.h> +#include <unistd.h> +#include <string.h> +#include <signal.h> +#include <err.h> +#include <sys/syscall.h> + +#include "helpers.h" + +static unsigned int nerrs; + +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 sigtrap(int sig, siginfo_t *si, void *ctx_void) +{ +} + +static void do_it(unsigned long extraflags) +{ + unsigned long flags; + + set_eflags(get_eflags() | extraflags); + syscall(SYS_getpid); + flags = get_eflags(); + set_eflags(X86_EFLAGS_IF | X86_EFLAGS_FIXED); + if ((flags & extraflags) == extraflags) { + printf("[OK]\tThe syscall worked and flags are still set\n"); + } else { + printf("[FAIL]\tThe syscall worked but flags were cleared (flags = 0x%lx but expected 0x%lx set)\n", + flags, extraflags); + nerrs++; + } +} + +int main(void) +{ + printf("[RUN]\tSet NT and issue a syscall\n"); + do_it(X86_EFLAGS_NT); + + printf("[RUN]\tSet AC and issue a syscall\n"); + do_it(X86_EFLAGS_AC); + + printf("[RUN]\tSet NT|AC and issue a syscall\n"); + do_it(X86_EFLAGS_NT | X86_EFLAGS_AC); + + /* + * Now try it again with TF set -- TF forces returns via IRET in all + * cases except non-ptregs-using 64-bit full fast path syscalls. + */ + + sethandler(SIGTRAP, sigtrap, 0); + + printf("[RUN]\tSet TF and issue a syscall\n"); + do_it(X86_EFLAGS_TF); + + printf("[RUN]\tSet NT|TF and issue a syscall\n"); + do_it(X86_EFLAGS_NT | X86_EFLAGS_TF); + + printf("[RUN]\tSet AC|TF and issue a syscall\n"); + do_it(X86_EFLAGS_AC | X86_EFLAGS_TF); + + printf("[RUN]\tSet NT|AC|TF and issue a syscall\n"); + do_it(X86_EFLAGS_NT | X86_EFLAGS_AC | X86_EFLAGS_TF); + + /* + * Now try DF. This is evil and it's plausible that we will crash + * glibc, but glibc would have to do something rather surprising + * for this to happen. + */ + printf("[RUN]\tSet DF and issue a syscall\n"); + do_it(X86_EFLAGS_DF); + + printf("[RUN]\tSet TF|DF and issue a syscall\n"); + do_it(X86_EFLAGS_TF | X86_EFLAGS_DF); + + return nerrs == 0 ? 0 : 1; +} |