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[PATCH v3 2/2] tests/tcg/s390x: Test SIGILL and SIGSEGV handling

Ilya Leoshkevich posted 2 patches 4 years, 8 months ago
Maintainers: David Hildenbrand <david@redhat.com>, Thomas Huth <thuth@redhat.com>, Laurent Vivier <laurent@vivier.eu>, Cornelia Huck <cohuck@redhat.com>, Richard Henderson <richard.henderson@linaro.org>
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[PATCH v3 2/2] tests/tcg/s390x: Test SIGILL and SIGSEGV 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/signal.c        | 163 ++++++++++++++++++++++++++++++++
 2 files changed, 164 insertions(+)
 create mode 100644 tests/tcg/s390x/signal.c

diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target
index 241ef28f61..cdb7d85316 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+=signal
diff --git a/tests/tcg/s390x/signal.c b/tests/tcg/s390x/signal.c
new file mode 100644
index 0000000000..c25d7dd019
--- /dev/null
+++ b/tests/tcg/s390x/signal.c
@@ -0,0 +1,163 @@
+#include <assert.h>
+#include <signal.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <ucontext.h>
+#include <unistd.h>
+
+/*
+ * Various instructions that generate SIGILL and SIGSEGV. They could have been
+ * defined in a separate .s file, but this would complicate the build, so the
+ * inline asm is used instead.
+ */
+
+void illegal_op(void);
+void after_illegal_op(void);
+asm(".globl\tillegal_op\n"
+    "illegal_op:\t.byte\t0x00,0x00\n"
+    "\t.globl\tafter_illegal_op\n"
+    "after_illegal_op:\tbr\t%r14");
+
+void stg(void *dst, unsigned long src);
+asm(".globl\tstg\n"
+    "stg:\tstg\t%r3,0(%r2)\n"
+    "\tbr\t%r14");
+
+void mvc_8(void *dst, void *src);
+asm(".globl\tmvc_8\n"
+    "mvc_8:\tmvc\t0(8,%r2),0(%r3)\n"
+    "\tbr\t%r14");
+
+static void safe_puts(const char *s)
+{
+    write(0, s, strlen(s));
+    write(0, "\n", 1);
+}
+
+enum exception {
+    exception_operation,
+    exception_translation,
+    exception_protection,
+};
+
+static struct {
+    int sig;
+    void *addr;
+    unsigned long psw_addr;
+    enum exception exception;
+} expected;
+
+static void handle_signal(int sig, siginfo_t *info, void *ucontext)
+{
+    void *page;
+    int err;
+
+    if (sig != expected.sig) {
+        safe_puts("[  FAILED  ] wrong signal");
+        _exit(1);
+    }
+
+    if (info->si_addr != expected.addr) {
+        safe_puts("[  FAILED  ] wrong si_addr");
+        _exit(1);
+    }
+
+    if (((ucontext_t *)ucontext)->uc_mcontext.psw.addr != expected.psw_addr) {
+        safe_puts("[  FAILED  ] wrong psw.addr");
+        _exit(1);
+    }
+
+    switch (expected.exception) {
+    case exception_translation:
+        page = mmap(expected.addr, 4096, PROT_READ | PROT_WRITE,
+                    MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
+        if (page != expected.addr) {
+            safe_puts("[  FAILED  ] mmap() failed");
+            _exit(1);
+        }
+        break;
+    case exception_protection:
+        err = mprotect(expected.addr, 4096, PROT_READ | PROT_WRITE);
+        if (err != 0) {
+            safe_puts("[  FAILED  ] mprotect() failed");
+            _exit(1);
+        }
+        break;
+    }
+}
+
+static void check_sigsegv(void *func, enum exception exception,
+                          unsigned long val)
+{
+    int prot;
+    unsigned long *page;
+    unsigned long *addr;
+    int err;
+
+    prot = exception == exception_translation ? PROT_NONE : PROT_READ;
+    page = mmap(NULL, 4096, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+    assert(page != MAP_FAILED);
+    if (exception == exception_translation) {
+        /* Hopefully nothing will be mapped at this address. */
+        err = munmap(page, 4096);
+        assert(err == 0);
+    }
+    addr = page + (val & 0x1ff);
+
+    expected.sig = SIGSEGV;
+    expected.addr = page;
+    expected.psw_addr = (unsigned long)func;
+    expected.exception = exception;
+    if (func == stg) {
+        stg(addr, val);
+    } else {
+        assert(func == mvc_8);
+        mvc_8(addr, &val);
+    }
+    assert(*addr == val);
+
+    err = munmap(page, 4096);
+    assert(err == 0);
+}
+
+int main(void)
+{
+    struct sigaction act;
+    int err;
+
+    memset(&act, 0, sizeof(act));
+    act.sa_sigaction = handle_signal;
+    act.sa_flags = SA_SIGINFO;
+    err = sigaction(SIGILL, &act, NULL);
+    assert(err == 0);
+    err = sigaction(SIGSEGV, &act, NULL);
+    assert(err == 0);
+
+    safe_puts("[ RUN      ] Operation exception");
+    expected.sig = SIGILL;
+    expected.addr = illegal_op;
+    expected.psw_addr = (unsigned long)after_illegal_op;
+    expected.exception = exception_operation;
+    illegal_op();
+    safe_puts("[       OK ]");
+
+    safe_puts("[ RUN      ] Translation exception from stg");
+    check_sigsegv(stg, exception_translation, 42);
+    safe_puts("[       OK ]");
+
+    safe_puts("[ RUN      ] Translation exception from mvc");
+    check_sigsegv(mvc_8, exception_translation, 4242);
+    safe_puts("[       OK ]");
+
+    safe_puts("[ RUN      ] Protection exception from stg");
+    check_sigsegv(stg, exception_protection, 424242);
+    safe_puts("[       OK ]");
+
+    safe_puts("[ RUN      ] Protection exception from mvc");
+    check_sigsegv(mvc_8, exception_protection, 42424242);
+    safe_puts("[       OK ]");
+
+    safe_puts("[  PASSED  ]");
+
+    return 0;
+}
-- 
2.31.1
Re: [PATCH v3 2/2] tests/tcg/s390x: Test SIGILL and SIGSEGV handling
Posted by jonathan.albrecht 4 years, 7 months ago 
On 2021-06-01 8:22 pm, 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/signal.c        | 163 ++++++++++++++++++++++++++++++++
>  2 files changed, 164 insertions(+)
>  create mode 100644 tests/tcg/s390x/signal.c
> 
> diff --git a/tests/tcg/s390x/Makefile.target 
> b/tests/tcg/s390x/Makefile.target
> index 241ef28f61..cdb7d85316 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+=signal
> diff --git a/tests/tcg/s390x/signal.c b/tests/tcg/s390x/signal.c
> new file mode 100644
> index 0000000000..c25d7dd019
> --- /dev/null
> +++ b/tests/tcg/s390x/signal.c
> @@ -0,0 +1,163 @@
> +#include <assert.h>
> +#include <signal.h>
> +#include <string.h>
> +#include <sys/mman.h>
> +#include <ucontext.h>
> +#include <unistd.h>
> +
> +/*
> + * Various instructions that generate SIGILL and SIGSEGV. They could 
> have been
> + * defined in a separate .s file, but this would complicate the build, 
> so the
> + * inline asm is used instead.
> + */
> +
> +void illegal_op(void);
> +void after_illegal_op(void);
> +asm(".globl\tillegal_op\n"
> +    "illegal_op:\t.byte\t0x00,0x00\n"
> +    "\t.globl\tafter_illegal_op\n"
> +    "after_illegal_op:\tbr\t%r14");
> +
> +void stg(void *dst, unsigned long src);
> +asm(".globl\tstg\n"
> +    "stg:\tstg\t%r3,0(%r2)\n"
> +    "\tbr\t%r14");
> +
> +void mvc_8(void *dst, void *src);
> +asm(".globl\tmvc_8\n"
> +    "mvc_8:\tmvc\t0(8,%r2),0(%r3)\n"
> +    "\tbr\t%r14");
> +
> +static void safe_puts(const char *s)
> +{
> +    write(0, s, strlen(s));
> +    write(0, "\n", 1);
> +}
> +
> +enum exception {
> +    exception_operation,
> +    exception_translation,
> +    exception_protection,
> +};
> +
> +static struct {
> +    int sig;
> +    void *addr;
> +    unsigned long psw_addr;
> +    enum exception exception;
> +} expected;
> +
> +static void handle_signal(int sig, siginfo_t *info, void *ucontext)
> +{
> +    void *page;
> +    int err;
> +
> +    if (sig != expected.sig) {
> +        safe_puts("[  FAILED  ] wrong signal");
> +        _exit(1);
> +    }
> +
> +    if (info->si_addr != expected.addr) {
> +        safe_puts("[  FAILED  ] wrong si_addr");
> +        _exit(1);
> +    }
> +
> +    if (((ucontext_t *)ucontext)->uc_mcontext.psw.addr != 
> expected.psw_addr) {
> +        safe_puts("[  FAILED  ] wrong psw.addr");
> +        _exit(1);
> +    }
> +
> +    switch (expected.exception) {

When I try to run 'make test-tcg' gcc 9.3.0 is complaining about a 
missing case:
/home/jalbrecht/src/qemu/tests/tcg/s390x/signal.c: In function 
'handle_signal':
/home/jalbrecht/src/qemu/tests/tcg/s390x/signal.c:70:5: error: 
enumeration value 'exception_operation' not handled in switch 
[-Werror=switch]
    70 |     switch (expected.exception) {
       |     ^~~~~~
cc1: all warnings being treated as errors

> +    case exception_translation:
> +        page = mmap(expected.addr, 4096, PROT_READ | PROT_WRITE,
> +                    MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
> +        if (page != expected.addr) {
> +            safe_puts("[  FAILED  ] mmap() failed");
> +            _exit(1);
> +        }
> +        break;
> +    case exception_protection:
> +        err = mprotect(expected.addr, 4096, PROT_READ | PROT_WRITE);
> +        if (err != 0) {
> +            safe_puts("[  FAILED  ] mprotect() failed");
> +            _exit(1);
> +        }
> +        break;
> +    }
> +}
> +
> +static void check_sigsegv(void *func, enum exception exception,
> +                          unsigned long val)
> +{
> +    int prot;
> +    unsigned long *page;
> +    unsigned long *addr;
> +    int err;
> +
> +    prot = exception == exception_translation ? PROT_NONE : PROT_READ;
> +    page = mmap(NULL, 4096, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
> +    assert(page != MAP_FAILED);
> +    if (exception == exception_translation) {
> +        /* Hopefully nothing will be mapped at this address. */
> +        err = munmap(page, 4096);
> +        assert(err == 0);
> +    }
> +    addr = page + (val & 0x1ff);
> +
> +    expected.sig = SIGSEGV;
> +    expected.addr = page;
> +    expected.psw_addr = (unsigned long)func;
> +    expected.exception = exception;
> +    if (func == stg) {
> +        stg(addr, val);
> +    } else {
> +        assert(func == mvc_8);
> +        mvc_8(addr, &val);
> +    }
> +    assert(*addr == val);
> +
> +    err = munmap(page, 4096);
> +    assert(err == 0);
> +}
> +
> +int main(void)
> +{
> +    struct sigaction act;
> +    int err;
> +
> +    memset(&act, 0, sizeof(act));
> +    act.sa_sigaction = handle_signal;
> +    act.sa_flags = SA_SIGINFO;
> +    err = sigaction(SIGILL, &act, NULL);
> +    assert(err == 0);
> +    err = sigaction(SIGSEGV, &act, NULL);
> +    assert(err == 0);
> +
> +    safe_puts("[ RUN      ] Operation exception");
> +    expected.sig = SIGILL;
> +    expected.addr = illegal_op;
> +    expected.psw_addr = (unsigned long)after_illegal_op;
> +    expected.exception = exception_operation;
> +    illegal_op();
> +    safe_puts("[       OK ]");
> +
> +    safe_puts("[ RUN      ] Translation exception from stg");
> +    check_sigsegv(stg, exception_translation, 42);
> +    safe_puts("[       OK ]");
> +
> +    safe_puts("[ RUN      ] Translation exception from mvc");
> +    check_sigsegv(mvc_8, exception_translation, 4242);
> +    safe_puts("[       OK ]");
> +
> +    safe_puts("[ RUN      ] Protection exception from stg");
> +    check_sigsegv(stg, exception_protection, 424242);
> +    safe_puts("[       OK ]");
> +
> +    safe_puts("[ RUN      ] Protection exception from mvc");
> +    check_sigsegv(mvc_8, exception_protection, 42424242);
> +    safe_puts("[       OK ]");
> +
> +    safe_puts("[  PASSED  ]");
> +
> +    return 0;
> +}
Re: [PATCH v3 2/2] tests/tcg/s390x: Test SIGILL and SIGSEGV handling
Posted by Ilya Leoshkevich 4 years, 7 months ago 
On Fri, 2021-06-18 at 09:47 -0400, jonathan.albrecht wrote:
> On 2021-06-01 8:22 pm, 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/signal.c        | 163
> > ++++++++++++++++++++++++++++++++
> >  2 files changed, 164 insertions(+)
> >  create mode 100644 tests/tcg/s390x/signal.c
> > 

[...]

> > +static void handle_signal(int sig, siginfo_t *info, void
> > *ucontext)
> > +{
> > +    void *page;
> > +    int err;
> > +
> > +    if (sig != expected.sig) {
> > +        safe_puts("[  FAILED  ] wrong signal");
> > +        _exit(1);
> > +    }
> > +
> > +    if (info->si_addr != expected.addr) {
> > +        safe_puts("[  FAILED  ] wrong si_addr");
> > +        _exit(1);
> > +    }
> > +
> > +    if (((ucontext_t *)ucontext)->uc_mcontext.psw.addr != 
> > expected.psw_addr) {
> > +        safe_puts("[  FAILED  ] wrong psw.addr");
> > +        _exit(1);
> > +    }
> > +
> > +    switch (expected.exception) {
> 
> When I try to run 'make test-tcg' gcc 9.3.0 is complaining about a 
> missing case:
> /home/jalbrecht/src/qemu/tests/tcg/s390x/signal.c: In function 
> 'handle_signal':
> /home/jalbrecht/src/qemu/tests/tcg/s390x/signal.c:70:5: error: 
> enumeration value 'exception_operation' not handled in switch 
> [-Werror=switch]
>     70 |     switch (expected.exception) {
>        |     ^~~~~~
> cc1: all warnings being treated as errors

I wonder how I didn't catch this, since I'm testing on Ubuntu 20.04
as well. Thank you, I will fix this.

Best regards,
Ilya

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