| Message ID | 20220503225157.1696774-3-iii@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | linux-user/s390x: Fix unwinding from signal handlers | expand |
On Wed, 2022-05-04 at 00:51 +0200, Ilya Leoshkevich wrote: > Add a small test to prevent regressions. > > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> > --- > tests/tcg/s390x/signals-s390x.c | 69 ++++++++++++++++++++++++++----- > -- > 1 file changed, 55 insertions(+), 14 deletions(-) > > diff --git a/tests/tcg/s390x/signals-s390x.c > b/tests/tcg/s390x/signals-s390x.c > index dc2f8ee59a..48c3b6cdfd 100644 > --- a/tests/tcg/s390x/signals-s390x.c > +++ b/tests/tcg/s390x/signals-s390x.c > @@ -1,4 +1,5 @@ > #include <assert.h> > +#include <execinfo.h> > #include <signal.h> > #include <string.h> > #include <sys/mman.h> > @@ -11,22 +12,28 @@ > * inline asm is used instead. > */ > > +#define DEFINE_ASM_FUNCTION(name, body) \ > + asm(".globl " #name "\n" \ > + #name ":\n" \ > + ".cfi_startproc\n" \ > + body "\n" \ > + "br %r14\n" \ > + ".cfi_endproc"); > + > 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"); > +extern const char after_illegal_op; > +DEFINE_ASM_FUNCTION(illegal_op, > + ".byte 0x00,0x00\n" > + ".globl after_illegal_op\n" > + "after_illegal_op:") > > void stg(void *dst, unsigned long src); > -asm(".globl\tstg\n" > - "stg:\tstg\t%r3,0(%r2)\n" > - "\tbr\t%r14"); > +DEFINE_ASM_FUNCTION(stg, "stg %r3,0(%r2)") > > void mvc_8(void *dst, void *src); > -asm(".globl\tmvc_8\n" > - "mvc_8:\tmvc\t0(8,%r2),0(%r3)\n" > - "\tbr\t%r14"); > +DEFINE_ASM_FUNCTION(mvc_8, "mvc 0(8,%r2),0(%r3)") > + > +extern const char return_from_main_1; > > static void safe_puts(const char *s) > { > @@ -49,8 +56,9 @@ static struct { > > static void handle_signal(int sig, siginfo_t *info, void *ucontext) > { > + int err, i, n_frames; > + void *frames[16]; > void *page; > - int err; > > if (sig != expected.sig) { > safe_puts("[ FAILED ] wrong signal"); > @@ -86,6 +94,17 @@ static void handle_signal(int sig, siginfo_t > *info, void *ucontext) > default: > break; > } > + > + n_frames = backtrace(frames, sizeof(frames) / > sizeof(frames[0])); > + for (i = 0; i < n_frames; i++) { > + if (frames[i] == &return_from_main_1) { > + break; > + } > + } > + if (i == n_frames) { > + safe_puts("[ FAILED ] backtrace() is broken"); > + _exit(1); > + } > } > > static void check_sigsegv(void *func, enum exception exception, > @@ -122,7 +141,7 @@ static void check_sigsegv(void *func, enum > exception exception, > assert(err == 0); > } > > -int main(void) > +int main_1(void) > { > struct sigaction act; > int err; > @@ -138,7 +157,7 @@ int main(void) > safe_puts("[ RUN ] Operation exception"); > expected.sig = SIGILL; > expected.addr = illegal_op; > - expected.psw_addr = (unsigned long)after_illegal_op; > + expected.psw_addr = (unsigned long)&after_illegal_op; > expected.exception = exception_operation; > illegal_op(); > safe_puts("[ OK ]"); > @@ -163,3 +182,25 @@ int main(void) > > _exit(0); > } > + > +/* > + * Define main() in assembly in order to test that unwinding from > signal > + * handlers until main() works. This way we can define a specific > point that > + * the unwinder should reach. This is also better than defining > main() in C > + * and using inline assembly to call main_1(), since it's not easy > to get all > + * the clobbers right. > + */ > + > +DEFINE_ASM_FUNCTION(main, > + "stmg %r14,%r15,112(%r15)\n" > + ".cfi_offset 14,-48\n" > + ".cfi_offset 15,-40\n" > + "lay %r15,-160(%r15)\n" > + ".cfi_def_cfa_offset 320\n" > + "brasl %r14,main_1\n" > + ".globl return_from_main_1\n" > + "return_from_main_1:\n" > + "lmg %r14,%r15,272(%r15)\n" > + ".cfi_restore 15\n" > + ".cfi_restore 14\n" > + ".cfi_def_cfa_offset 160"); Ping.
On 19/05/2022 13.34, Ilya Leoshkevich wrote: > On Wed, 2022-05-04 at 00:51 +0200, Ilya Leoshkevich wrote: >> Add a small test to prevent regressions. >> >> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> >> --- >> tests/tcg/s390x/signals-s390x.c | 69 ++++++++++++++++++++++++++----- >> -- >> 1 file changed, 55 insertions(+), 14 deletions(-) >> >> diff --git a/tests/tcg/s390x/signals-s390x.c >> b/tests/tcg/s390x/signals-s390x.c >> index dc2f8ee59a..48c3b6cdfd 100644 >> --- a/tests/tcg/s390x/signals-s390x.c >> +++ b/tests/tcg/s390x/signals-s390x.c >> @@ -1,4 +1,5 @@ >> #include <assert.h> >> +#include <execinfo.h> >> #include <signal.h> >> #include <string.h> >> #include <sys/mman.h> >> @@ -11,22 +12,28 @@ >> * inline asm is used instead. >> */ >> >> +#define DEFINE_ASM_FUNCTION(name, body) \ >> + asm(".globl " #name "\n" \ >> + #name ":\n" \ >> + ".cfi_startproc\n" \ >> + body "\n" \ >> + "br %r14\n" \ >> + ".cfi_endproc"); >> + >> 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"); >> +extern const char after_illegal_op; >> +DEFINE_ASM_FUNCTION(illegal_op, >> + ".byte 0x00,0x00\n" >> + ".globl after_illegal_op\n" >> + "after_illegal_op:") >> >> void stg(void *dst, unsigned long src); >> -asm(".globl\tstg\n" >> - "stg:\tstg\t%r3,0(%r2)\n" >> - "\tbr\t%r14"); >> +DEFINE_ASM_FUNCTION(stg, "stg %r3,0(%r2)") >> >> void mvc_8(void *dst, void *src); >> -asm(".globl\tmvc_8\n" >> - "mvc_8:\tmvc\t0(8,%r2),0(%r3)\n" >> - "\tbr\t%r14"); >> +DEFINE_ASM_FUNCTION(mvc_8, "mvc 0(8,%r2),0(%r3)") >> + >> +extern const char return_from_main_1; >> >> static void safe_puts(const char *s) >> { >> @@ -49,8 +56,9 @@ static struct { >> >> static void handle_signal(int sig, siginfo_t *info, void *ucontext) >> { >> + int err, i, n_frames; >> + void *frames[16]; >> void *page; >> - int err; >> >> if (sig != expected.sig) { >> safe_puts("[ FAILED ] wrong signal"); >> @@ -86,6 +94,17 @@ static void handle_signal(int sig, siginfo_t >> *info, void *ucontext) >> default: >> break; >> } >> + >> + n_frames = backtrace(frames, sizeof(frames) / >> sizeof(frames[0])); >> + for (i = 0; i < n_frames; i++) { >> + if (frames[i] == &return_from_main_1) { >> + break; >> + } >> + } >> + if (i == n_frames) { >> + safe_puts("[ FAILED ] backtrace() is broken"); >> + _exit(1); >> + } >> } >> >> static void check_sigsegv(void *func, enum exception exception, >> @@ -122,7 +141,7 @@ static void check_sigsegv(void *func, enum >> exception exception, >> assert(err == 0); >> } >> >> -int main(void) >> +int main_1(void) >> { >> struct sigaction act; >> int err; >> @@ -138,7 +157,7 @@ int main(void) >> safe_puts("[ RUN ] Operation exception"); >> expected.sig = SIGILL; >> expected.addr = illegal_op; >> - expected.psw_addr = (unsigned long)after_illegal_op; >> + expected.psw_addr = (unsigned long)&after_illegal_op; >> expected.exception = exception_operation; >> illegal_op(); >> safe_puts("[ OK ]"); >> @@ -163,3 +182,25 @@ int main(void) >> >> _exit(0); >> } >> + >> +/* >> + * Define main() in assembly in order to test that unwinding from >> signal >> + * handlers until main() works. This way we can define a specific >> point that >> + * the unwinder should reach. This is also better than defining >> main() in C >> + * and using inline assembly to call main_1(), since it's not easy >> to get all >> + * the clobbers right. >> + */ >> + >> +DEFINE_ASM_FUNCTION(main, >> + "stmg %r14,%r15,112(%r15)\n" >> + ".cfi_offset 14,-48\n" >> + ".cfi_offset 15,-40\n" >> + "lay %r15,-160(%r15)\n" >> + ".cfi_def_cfa_offset 320\n" >> + "brasl %r14,main_1\n" >> + ".globl return_from_main_1\n" >> + "return_from_main_1:\n" >> + "lmg %r14,%r15,272(%r15)\n" >> + ".cfi_restore 15\n" >> + ".cfi_restore 14\n" >> + ".cfi_def_cfa_offset 160"); > > Ping. Acked-by: Thomas Huth <thuth@redhat.com> Laurent, do you want to take these two patches through your linux-user branch, or shall I take them via the s390x branch? Thomas
Le 24/05/2022 à 11:56, Thomas Huth a écrit : > On 19/05/2022 13.34, Ilya Leoshkevich wrote: >> On Wed, 2022-05-04 at 00:51 +0200, Ilya Leoshkevich wrote: >>> Add a small test to prevent regressions. >>> >>> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> >>> --- >>> tests/tcg/s390x/signals-s390x.c | 69 ++++++++++++++++++++++++++----- >>> -- >>> 1 file changed, 55 insertions(+), 14 deletions(-) >>> >>> diff --git a/tests/tcg/s390x/signals-s390x.c >>> b/tests/tcg/s390x/signals-s390x.c >>> index dc2f8ee59a..48c3b6cdfd 100644 >>> --- a/tests/tcg/s390x/signals-s390x.c >>> +++ b/tests/tcg/s390x/signals-s390x.c >>> @@ -1,4 +1,5 @@ >>> #include <assert.h> >>> +#include <execinfo.h> >>> #include <signal.h> >>> #include <string.h> >>> #include <sys/mman.h> >>> @@ -11,22 +12,28 @@ >>> * inline asm is used instead. >>> */ >>> +#define DEFINE_ASM_FUNCTION(name, body) \ >>> + asm(".globl " #name "\n" \ >>> + #name ":\n" \ >>> + ".cfi_startproc\n" \ >>> + body "\n" \ >>> + "br %r14\n" \ >>> + ".cfi_endproc"); >>> + >>> 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"); >>> +extern const char after_illegal_op; >>> +DEFINE_ASM_FUNCTION(illegal_op, >>> + ".byte 0x00,0x00\n" >>> + ".globl after_illegal_op\n" >>> + "after_illegal_op:") >>> void stg(void *dst, unsigned long src); >>> -asm(".globl\tstg\n" >>> - "stg:\tstg\t%r3,0(%r2)\n" >>> - "\tbr\t%r14"); >>> +DEFINE_ASM_FUNCTION(stg, "stg %r3,0(%r2)") >>> void mvc_8(void *dst, void *src); >>> -asm(".globl\tmvc_8\n" >>> - "mvc_8:\tmvc\t0(8,%r2),0(%r3)\n" >>> - "\tbr\t%r14"); >>> +DEFINE_ASM_FUNCTION(mvc_8, "mvc 0(8,%r2),0(%r3)") >>> + >>> +extern const char return_from_main_1; >>> static void safe_puts(const char *s) >>> { >>> @@ -49,8 +56,9 @@ static struct { >>> static void handle_signal(int sig, siginfo_t *info, void *ucontext) >>> { >>> + int err, i, n_frames; >>> + void *frames[16]; >>> void *page; >>> - int err; >>> if (sig != expected.sig) { >>> safe_puts("[ FAILED ] wrong signal"); >>> @@ -86,6 +94,17 @@ static void handle_signal(int sig, siginfo_t >>> *info, void *ucontext) >>> default: >>> break; >>> } >>> + >>> + n_frames = backtrace(frames, sizeof(frames) / >>> sizeof(frames[0])); >>> + for (i = 0; i < n_frames; i++) { >>> + if (frames[i] == &return_from_main_1) { >>> + break; >>> + } >>> + } >>> + if (i == n_frames) { >>> + safe_puts("[ FAILED ] backtrace() is broken"); >>> + _exit(1); >>> + } >>> } >>> static void check_sigsegv(void *func, enum exception exception, >>> @@ -122,7 +141,7 @@ static void check_sigsegv(void *func, enum >>> exception exception, >>> assert(err == 0); >>> } >>> -int main(void) >>> +int main_1(void) >>> { >>> struct sigaction act; >>> int err; >>> @@ -138,7 +157,7 @@ int main(void) >>> safe_puts("[ RUN ] Operation exception"); >>> expected.sig = SIGILL; >>> expected.addr = illegal_op; >>> - expected.psw_addr = (unsigned long)after_illegal_op; >>> + expected.psw_addr = (unsigned long)&after_illegal_op; >>> expected.exception = exception_operation; >>> illegal_op(); >>> safe_puts("[ OK ]"); >>> @@ -163,3 +182,25 @@ int main(void) >>> _exit(0); >>> } >>> + >>> +/* >>> + * Define main() in assembly in order to test that unwinding from >>> signal >>> + * handlers until main() works. This way we can define a specific >>> point that >>> + * the unwinder should reach. This is also better than defining >>> main() in C >>> + * and using inline assembly to call main_1(), since it's not easy >>> to get all >>> + * the clobbers right. >>> + */ >>> + >>> +DEFINE_ASM_FUNCTION(main, >>> + "stmg %r14,%r15,112(%r15)\n" >>> + ".cfi_offset 14,-48\n" >>> + ".cfi_offset 15,-40\n" >>> + "lay %r15,-160(%r15)\n" >>> + ".cfi_def_cfa_offset 320\n" >>> + "brasl %r14,main_1\n" >>> + ".globl return_from_main_1\n" >>> + "return_from_main_1:\n" >>> + "lmg %r14,%r15,272(%r15)\n" >>> + ".cfi_restore 15\n" >>> + ".cfi_restore 14\n" >>> + ".cfi_def_cfa_offset 160"); >> >> Ping. > > Acked-by: Thomas Huth <thuth@redhat.com> > > Laurent, do you want to take these two patches through your linux-user branch, or shall I take them > via the s390x branch? I will take both. Thanks, Laurent
diff --git a/tests/tcg/s390x/signals-s390x.c b/tests/tcg/s390x/signals-s390x.c index dc2f8ee59a..48c3b6cdfd 100644 --- a/tests/tcg/s390x/signals-s390x.c +++ b/tests/tcg/s390x/signals-s390x.c @@ -1,4 +1,5 @@ #include <assert.h> +#include <execinfo.h> #include <signal.h> #include <string.h> #include <sys/mman.h> @@ -11,22 +12,28 @@ * inline asm is used instead. */ +#define DEFINE_ASM_FUNCTION(name, body) \ + asm(".globl " #name "\n" \ + #name ":\n" \ + ".cfi_startproc\n" \ + body "\n" \ + "br %r14\n" \ + ".cfi_endproc"); + 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"); +extern const char after_illegal_op; +DEFINE_ASM_FUNCTION(illegal_op, + ".byte 0x00,0x00\n" + ".globl after_illegal_op\n" + "after_illegal_op:") void stg(void *dst, unsigned long src); -asm(".globl\tstg\n" - "stg:\tstg\t%r3,0(%r2)\n" - "\tbr\t%r14"); +DEFINE_ASM_FUNCTION(stg, "stg %r3,0(%r2)") void mvc_8(void *dst, void *src); -asm(".globl\tmvc_8\n" - "mvc_8:\tmvc\t0(8,%r2),0(%r3)\n" - "\tbr\t%r14"); +DEFINE_ASM_FUNCTION(mvc_8, "mvc 0(8,%r2),0(%r3)") + +extern const char return_from_main_1; static void safe_puts(const char *s) { @@ -49,8 +56,9 @@ static struct { static void handle_signal(int sig, siginfo_t *info, void *ucontext) { + int err, i, n_frames; + void *frames[16]; void *page; - int err; if (sig != expected.sig) { safe_puts("[ FAILED ] wrong signal"); @@ -86,6 +94,17 @@ static void handle_signal(int sig, siginfo_t *info, void *ucontext) default: break; } + + n_frames = backtrace(frames, sizeof(frames) / sizeof(frames[0])); + for (i = 0; i < n_frames; i++) { + if (frames[i] == &return_from_main_1) { + break; + } + } + if (i == n_frames) { + safe_puts("[ FAILED ] backtrace() is broken"); + _exit(1); + } } static void check_sigsegv(void *func, enum exception exception, @@ -122,7 +141,7 @@ static void check_sigsegv(void *func, enum exception exception, assert(err == 0); } -int main(void) +int main_1(void) { struct sigaction act; int err; @@ -138,7 +157,7 @@ int main(void) safe_puts("[ RUN ] Operation exception"); expected.sig = SIGILL; expected.addr = illegal_op; - expected.psw_addr = (unsigned long)after_illegal_op; + expected.psw_addr = (unsigned long)&after_illegal_op; expected.exception = exception_operation; illegal_op(); safe_puts("[ OK ]"); @@ -163,3 +182,25 @@ int main(void) _exit(0); } + +/* + * Define main() in assembly in order to test that unwinding from signal + * handlers until main() works. This way we can define a specific point that + * the unwinder should reach. This is also better than defining main() in C + * and using inline assembly to call main_1(), since it's not easy to get all + * the clobbers right. + */ + +DEFINE_ASM_FUNCTION(main, + "stmg %r14,%r15,112(%r15)\n" + ".cfi_offset 14,-48\n" + ".cfi_offset 15,-40\n" + "lay %r15,-160(%r15)\n" + ".cfi_def_cfa_offset 320\n" + "brasl %r14,main_1\n" + ".globl return_from_main_1\n" + "return_from_main_1:\n" + "lmg %r14,%r15,272(%r15)\n" + ".cfi_restore 15\n" + ".cfi_restore 14\n" + ".cfi_def_cfa_offset 160");
Add a small test to prevent regressions. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> --- tests/tcg/s390x/signals-s390x.c | 69 ++++++++++++++++++++++++++------- 1 file changed, 55 insertions(+), 14 deletions(-)