| Message ID | 20220407115948.1664232-1-stli@linux.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | S390: Fix elf/tst-audit25[ab] | expand |
On 07/04/2022 08:59, Stefan Liebler via Libc-alpha wrote: > If glibc is configured with --disable-default-pie and build on > s390 with -O3, the tests elf/tst-audit25a and elf/tst-audit25b are > failing as there are additional la_symbind lines for free and malloc. > It turns out that those belong to the executable. In fact those are > the PLT-stubs. Furthermore la_symbind is also called for calloc and > realloc symbols, but those belong to libc. > > Those functions are not called at all, but dlsym'ed in > elf/dl-minimal.c: > __rtld_malloc_init_real (struct link_map *main_map) > { > ... > void *new_calloc = lookup_malloc_symbol (main_map, "calloc", &version); > void *new_free = lookup_malloc_symbol (main_map, "free", &version); > void *new_malloc = lookup_malloc_symbol (main_map, "malloc", &version); > void *new_realloc = lookup_malloc_symbol (main_map, "realloc", &version); > ... > } > > Therefore, this commit just ignored symbols with LA_SYMB_DLSYM flag. LGTM, thank. Why don't we see in other configuration and/or architecture? What s390 is doing different here? Reviewed-by: Adheemrval Zanella <adhemerval.zanella@linaro.org> > --- > elf/tst-auditmod25.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/elf/tst-auditmod25.c b/elf/tst-auditmod25.c > index 20640a8daf..0524c5aab1 100644 > --- a/elf/tst-auditmod25.c > +++ b/elf/tst-auditmod25.c > @@ -72,7 +72,8 @@ la_symbind32 (Elf32_Sym *sym, unsigned int ndx, > unsigned int *flags, const char *symname) > #endif > { > - if (*refcook != -1 && *defcook != -1 && symname[0] != '\0') > + if (*refcook != -1 && *defcook != -1 && symname[0] != '\0' > + && (*flags & LA_SYMB_DLSYM) == 0) > fprintf (stderr, "la_symbind: %s %u\n", symname, > *flags & (LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT) ? 1 : 0); > return sym->st_value;
On 07/04/2022 15:36, Adhemerval Zanella via Libc-alpha wrote: > > > On 07/04/2022 08:59, Stefan Liebler via Libc-alpha wrote: >> If glibc is configured with --disable-default-pie and build on >> s390 with -O3, the tests elf/tst-audit25a and elf/tst-audit25b are >> failing as there are additional la_symbind lines for free and malloc. >> It turns out that those belong to the executable. In fact those are >> the PLT-stubs. Furthermore la_symbind is also called for calloc and >> realloc symbols, but those belong to libc. >> >> Those functions are not called at all, but dlsym'ed in >> elf/dl-minimal.c: >> __rtld_malloc_init_real (struct link_map *main_map) >> { >> ... >> void *new_calloc = lookup_malloc_symbol (main_map, "calloc", &version); >> void *new_free = lookup_malloc_symbol (main_map, "free", &version); >> void *new_malloc = lookup_malloc_symbol (main_map, "malloc", &version); >> void *new_realloc = lookup_malloc_symbol (main_map, "realloc", &version); >> ... >> } >> >> Therefore, this commit just ignored symbols with LA_SYMB_DLSYM flag. > > LGTM, thank. Why don't we see in other configuration and/or architecture? > What s390 is doing different here? > > Reviewed-by: Adheemrval Zanella <adhemerval.zanella@linaro.org> > Thanks. Then I'll commit the patch. You are right I have not seen it on x86_64. Perhaps it triggers something in s390x-code in ld regarding -Bsymbolic and pointer-equality-reasons. But this is only a guess. Thanks, Stefan
diff --git a/elf/tst-auditmod25.c b/elf/tst-auditmod25.c index 20640a8daf..0524c5aab1 100644 --- a/elf/tst-auditmod25.c +++ b/elf/tst-auditmod25.c @@ -72,7 +72,8 @@ la_symbind32 (Elf32_Sym *sym, unsigned int ndx, unsigned int *flags, const char *symname) #endif { - if (*refcook != -1 && *defcook != -1 && symname[0] != '\0') + if (*refcook != -1 && *defcook != -1 && symname[0] != '\0' + && (*flags & LA_SYMB_DLSYM) == 0) fprintf (stderr, "la_symbind: %s %u\n", symname, *flags & (LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT) ? 1 : 0); return sym->st_value;
If glibc is configured with --disable-default-pie and build on s390 with -O3, the tests elf/tst-audit25a and elf/tst-audit25b are failing as there are additional la_symbind lines for free and malloc. It turns out that those belong to the executable. In fact those are the PLT-stubs. Furthermore la_symbind is also called for calloc and realloc symbols, but those belong to libc. Those functions are not called at all, but dlsym'ed in elf/dl-minimal.c: __rtld_malloc_init_real (struct link_map *main_map) { ... void *new_calloc = lookup_malloc_symbol (main_map, "calloc", &version); void *new_free = lookup_malloc_symbol (main_map, "free", &version); void *new_malloc = lookup_malloc_symbol (main_map, "malloc", &version); void *new_realloc = lookup_malloc_symbol (main_map, "realloc", &version); ... } Therefore, this commit just ignored symbols with LA_SYMB_DLSYM flag. --- elf/tst-auditmod25.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)