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[PATCH 2/2] tests/tcg/s390x: Test SIGILL handling

Ilya Leoshkevich posted 2 patches 4 years, 8 months ago
Maintainers: Thomas Huth <thuth@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, David Hildenbrand <david@redhat.com>, Laurent Vivier <laurent@vivier.eu>, Cornelia Huck <cohuck@redhat.com>
[PATCH 2/2] tests/tcg/s390x: Test SIGILL handling
Posted by Ilya Leoshkevich 4 years, 8 months ago 
Verify that s390x-specific uc_mcontext.psw.addr is reported correctly.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 tests/tcg/s390x/Makefile.target |  1 +
 tests/tcg/s390x/sigill.c        | 41 +++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+)
 create mode 100644 tests/tcg/s390x/sigill.c

diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target
index 241ef28f61..8699d829a5 100644
--- a/tests/tcg/s390x/Makefile.target
+++ b/tests/tcg/s390x/Makefile.target
@@ -8,3 +8,4 @@ TESTS+=exrl-trtr
 TESTS+=pack
 TESTS+=mvo
 TESTS+=mvc
+TESTS+=sigill
diff --git a/tests/tcg/s390x/sigill.c b/tests/tcg/s390x/sigill.c
new file mode 100644
index 0000000000..f8021dc6af
--- /dev/null
+++ b/tests/tcg/s390x/sigill.c
@@ -0,0 +1,41 @@
+#include <assert.h>
+#include <signal.h>
+#include <string.h>
+#include <ucontext.h>
+#include <unistd.h>
+
+extern char expected_si_addr[];
+extern char expected_psw_addr[];
+
+static void handle_signal(int sig, siginfo_t *info, void *ucontext)
+{
+    if (sig != SIGILL) {
+        _exit(1);
+    }
+
+    if (info->si_addr != expected_si_addr) {
+        _exit(2);
+    }
+
+    if (((ucontext_t *)ucontext)->uc_mcontext.psw.addr !=
+            (unsigned long)expected_psw_addr) {
+        _exit(3);
+    }
+}
+
+int main(void)
+{
+    struct sigaction act;
+
+    memset(&act, 0, sizeof(act));
+    act.sa_sigaction = handle_signal;
+    act.sa_flags = SA_SIGINFO;
+
+    int ret = sigaction(SIGILL, &act, NULL);
+    assert(ret == 0);
+
+    asm volatile("expected_si_addr:\t.byte\t0x00,0x00\n"
+                 "expected_psw_addr:");
+
+    return 0;
+}
-- 
2.31.1
Re: [PATCH 2/2] tests/tcg/s390x: Test SIGILL handling
Posted by David Hildenbrand 4 years, 8 months ago 
On 21.05.21 05:01, Ilya Leoshkevich wrote:
> Verify that s390x-specific uc_mcontext.psw.addr is reported correctly.
> 
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> ---
>   tests/tcg/s390x/Makefile.target |  1 +
>   tests/tcg/s390x/sigill.c        | 41 +++++++++++++++++++++++++++++++++
>   2 files changed, 42 insertions(+)
>   create mode 100644 tests/tcg/s390x/sigill.c
> 
> diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target
> index 241ef28f61..8699d829a5 100644
> --- a/tests/tcg/s390x/Makefile.target
> +++ b/tests/tcg/s390x/Makefile.target
> @@ -8,3 +8,4 @@ TESTS+=exrl-trtr
>   TESTS+=pack
>   TESTS+=mvo
>   TESTS+=mvc
> +TESTS+=sigill
> diff --git a/tests/tcg/s390x/sigill.c b/tests/tcg/s390x/sigill.c
> new file mode 100644
> index 0000000000..f8021dc6af
> --- /dev/null
> +++ b/tests/tcg/s390x/sigill.c
> @@ -0,0 +1,41 @@
> +#include <assert.h>
> +#include <signal.h>
> +#include <string.h>
> +#include <ucontext.h>
> +#include <unistd.h>
> +
> +extern char expected_si_addr[];
> +extern char expected_psw_addr[];

Why "extern" ? For the magic inline asm below to work?

> +
> +static void handle_signal(int sig, siginfo_t *info, void *ucontext)
> +{
> +    if (sig != SIGILL) {
> +        _exit(1);
> +    }
> +
> +    if (info->si_addr != expected_si_addr) {
> +        _exit(2);
> +    }
> +
> +    if (((ucontext_t *)ucontext)->uc_mcontext.psw.addr !=
> +            (unsigned long)expected_psw_addr) {
> +        _exit(3);
> +    }
> +}
> +
> +int main(void)
> +{
> +    struct sigaction act;
> +
> +    memset(&act, 0, sizeof(act));
> +    act.sa_sigaction = handle_signal;
> +    act.sa_flags = SA_SIGINFO;
> +
> +    int ret = sigaction(SIGILL, &act, NULL);

Mixing code and declaration.

> +    assert(ret == 0);
> +
> +    asm volatile("expected_si_addr:\t.byte\t0x00,0x00\n"
> +                 "expected_psw_addr:");

At least I am confused how the right values actually end up in 
expected_si_addr and expected_psw_addr.

Can we maybe add a comment? This looks quite hacky ;)

-- 
Thanks,

David / dhildenb
Re: [PATCH 2/2] tests/tcg/s390x: Test SIGILL handling
Posted by Ilya Leoshkevich 4 years, 8 months ago 
On Fri, 2021-05-21 at 09:54 +0200, David Hildenbrand wrote:
> On 21.05.21 05:01, Ilya Leoshkevich wrote:
> > Verify that s390x-specific uc_mcontext.psw.addr is reported
> > correctly.
> > 
> > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> > ---
> >   tests/tcg/s390x/Makefile.target |  1 +
> >   tests/tcg/s390x/sigill.c        | 41
> > +++++++++++++++++++++++++++++++++
> >   2 files changed, 42 insertions(+)
> >   create mode 100644 tests/tcg/s390x/sigill.c
> > 
> > diff --git a/tests/tcg/s390x/Makefile.target
> > b/tests/tcg/s390x/Makefile.target
> > index 241ef28f61..8699d829a5 100644
> > --- a/tests/tcg/s390x/Makefile.target
> > +++ b/tests/tcg/s390x/Makefile.target
> > @@ -8,3 +8,4 @@ TESTS+=exrl-trtr
> >   TESTS+=pack
> >   TESTS+=mvo
> >   TESTS+=mvc
> > +TESTS+=sigill
> > diff --git a/tests/tcg/s390x/sigill.c b/tests/tcg/s390x/sigill.c
> > new file mode 100644
> > index 0000000000..f8021dc6af
> > --- /dev/null
> > +++ b/tests/tcg/s390x/sigill.c
> > @@ -0,0 +1,41 @@
> > +#include <assert.h>
> > +#include <signal.h>
> > +#include <string.h>
> > +#include <ucontext.h>
> > +#include <unistd.h>
> > +
> > +extern char expected_si_addr[];
> > +extern char expected_psw_addr[];
> 
> Why "extern" ? For the magic inline asm below to work?

Yes - it cannot be static, because AFAIK there is no such thing as
static variable declaration (one can only define static variables).

> > +
> > +static void handle_signal(int sig, siginfo_t *info, void
> > *ucontext)
> > +{
> > +    if (sig != SIGILL) {
> > +        _exit(1);
> > +    }
> > +
> > +    if (info->si_addr != expected_si_addr) {
> > +        _exit(2);
> > +    }
> > +
> > +    if (((ucontext_t *)ucontext)->uc_mcontext.psw.addr !=
> > +            (unsigned long)expected_psw_addr) {
> > +        _exit(3);
> > +    }
> > +}
> > +
> > +int main(void)
> > +{
> > +    struct sigaction act;
> > +
> > +    memset(&act, 0, sizeof(act));
> > +    act.sa_sigaction = handle_signal;
> > +    act.sa_flags = SA_SIGINFO;
> > +
> > +    int ret = sigaction(SIGILL, &act, NULL);
> 
> Mixing code and declaration.

Ouch, will fix.

> > +    assert(ret == 0);
> > +
> > +    asm volatile("expected_si_addr:\t.byte\t0x00,0x00\n"
> > +                 "expected_psw_addr:");
> 
> At least I am confused how the right values actually end up in 
> expected_si_addr and expected_psw_addr.
> 
> Can we maybe add a comment? This looks quite hacky ;)

This whole construction is roughly the same as having sigill.s file
with:

.globl expected_si_addr
expected_si_addr: .byte 0,0
.globl expected_psw_addr
expected_psw_addr: br 14

and sigill.h file with:

void expected_si_addr(void);
extern char expected_psw_addr[];

Doing it this way would complicate the build, so I thought it would be
better to just put everything into a single file.

Patchew 2.1-devel-b67e4c2

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