diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-07-05 12:23:49 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-07-05 12:23:49 -0700 |
commit | 72674d480076067d627e708c0a062dd900438bd7 (patch) | |
tree | 8ae54e966f78e59d48f9edad7aa3362eb87c2a9c /tools/testing/selftests/x86/syscall_nt.c | |
parent | f23dbe18930ba992f5c8c7b31e80f40dd6716081 (diff) | |
parent | cc801833a171163edb6385425349ba8903bd1b20 (diff) |
Merge tag 'x86-urgent-2020-07-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A series of fixes for x86:
- Reset MXCSR in kernel_fpu_begin() to prevent using a stale user
space value.
- Prevent writing MSR_TEST_CTRL on CPUs which are not explicitly
whitelisted for split lock detection. Some CPUs which do not
support it crash even when the MSR is written to 0 which is the
default value.
- Fix the XEN PV fallout of the entry code rework
- Fix the 32bit fallout of the entry code rework
- Add more selftests to ensure that these entry problems don't come
back.
- Disable 16 bit segments on XEN PV. It's not supported because XEN
PV does not implement ESPFIX64"
* tag 'x86-urgent-2020-07-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ldt: Disable 16-bit segments on Xen PV
x86/entry/32: Fix #MC and #DB wiring on x86_32
x86/entry/xen: Route #DB correctly on Xen PV
x86/entry, selftests: Further improve user entry sanity checks
x86/entry/compat: Clear RAX high bits on Xen PV SYSENTER
selftests/x86: Consolidate and fix get/set_eflags() helpers
selftests/x86/syscall_nt: Clear weird flags after each test
selftests/x86/syscall_nt: Add more flag combinations
x86/entry/64/compat: Fix Xen PV SYSENTER frame setup
x86/entry: Move SYSENTER's regs->sp and regs->flags fixups into C
x86/entry: Assert that syscalls are on the right stack
x86/split_lock: Don't write MSR_TEST_CTRL on CPUs that aren't whitelisted
x86/fpu: Reset MXCSR to default in kernel_fpu_begin()
Diffstat (limited to 'tools/testing/selftests/x86/syscall_nt.c')
-rw-r--r-- | tools/testing/selftests/x86/syscall_nt.c | 47 |
1 files changed, 28 insertions, 19 deletions
diff --git a/tools/testing/selftests/x86/syscall_nt.c b/tools/testing/selftests/x86/syscall_nt.c index 02309a195041..a108b80dd082 100644 --- a/tools/testing/selftests/x86/syscall_nt.c +++ b/tools/testing/selftests/x86/syscall_nt.c @@ -13,29 +13,11 @@ #include <signal.h> #include <err.h> #include <sys/syscall.h> -#include <asm/processor-flags.h> -#ifdef __x86_64__ -# define WIDTH "q" -#else -# define WIDTH "l" -#endif +#include "helpers.h" static unsigned int nerrs; -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"); -} - static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), int flags) { @@ -59,6 +41,7 @@ static void do_it(unsigned long extraflags) 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 { @@ -73,6 +56,12 @@ 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. @@ -80,8 +69,28 @@ int main(void) 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; } |