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author | NeilBrown <neilb@suse.com> | 2015-09-05 11:07:04 +0200 |
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committer | NeilBrown <neilb@suse.com> | 2015-09-05 11:08:32 +0200 |
commit | e89c6fdf9e0eb1b5a03574d4ca73e83eae8deb91 (patch) | |
tree | f9df292ed03a5a3c4ddc658ae3646f02a1ffafce /tools/testing/selftests/x86/syscall_nt.c | |
parent | c3cce6cda162eb2b2960a85d9c8992f4f3be85d0 (diff) | |
parent | 1081230b748de8f03f37f80c53dfa89feda9b8de (diff) | |
download | op-kernel-dev-e89c6fdf9e0eb1b5a03574d4ca73e83eae8deb91.zip op-kernel-dev-e89c6fdf9e0eb1b5a03574d4ca73e83eae8deb91.tar.gz |
Merge linux-block/for-4.3/core into md/for-linux
There were a few conflicts that are fairly easy to resolve.
Signed-off-by: NeilBrown <neilb@suse.com>
Diffstat (limited to 'tools/testing/selftests/x86/syscall_nt.c')
-rw-r--r-- | tools/testing/selftests/x86/syscall_nt.c | 54 |
1 files changed, 54 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 0000000..60c06af4 --- /dev/null +++ b/tools/testing/selftests/x86/syscall_nt.c @@ -0,0 +1,54 @@ +/* + * syscall_nt.c - checks syscalls with NT set + * 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. + * + * 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 <sys/syscall.h> +#include <asm/processor-flags.h> + +#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"); +} + +int main() +{ + printf("[RUN]\tSet NT and issue a syscall\n"); + set_eflags(get_eflags() | X86_EFLAGS_NT); + syscall(SYS_getpid); + if (get_eflags() & X86_EFLAGS_NT) { + printf("[OK]\tThe syscall worked and NT is still set\n"); + return 0; + } else { + printf("[FAIL]\tThe syscall worked but NT was cleared\n"); + return 1; + } +} |