[patch+7.5.1] Work around PR libc/13097 "linux-vdso.so.1" #3
Luis Gustavo
luis_gustavo@mentor.com
Fri Nov 23 11:30:00 GMT 2012
On 11/22/2012 06:17 PM, Jan Kratochvil wrote:
> Hi,
>
> this is an updated version of
> [RFC] Work around PR libc/13097 "linux-vdso.so.1" #2
> http://sourceware.org/ml/gdb-patches/2011-08/msg00331.html
> according to the Tom's comment
> http://sourceware.org/bugzilla/show_bug.cgi?id=14466#c3
>
> I remembered it when Joel plans 7.5.1 release, the patch is safe enough and it
> is a FAQ at least on IRC.
>
> Fedora does not have this issue with its Fedora glibc but I have it
> reproducible with FSF glibc build:
> ./gdb -ex r --args $HOME/glibc-root/lib/ld-linux-x86-64.so.2 --library-path $HOME/glibc-root/lib /bin/true
> Starting program: /home/.../glibc-root/lib/ld-linux-x86-64.so.2 --library-path /home/.../glibc-root/lib /bin/true
> warning: Could not load shared library symbols for linux-vdso.so.1.
> Do you need "set solib-search-path" or "set sysroot"?
> [Inferior 1 (process 31807) exited normally]
>
> So there is no testcase as I do not know a real OS where it fails (it probably
> fails on Ubuntu AFAIK).
>
> No regressions on {x86_64,x86_64-m32,i686}-fedora18-linux-gnu.
>
>
> Thanks,
> Jan
>
>
> gdb/
> 2012-11-22 Jan Kratochvil<jan.kratochvil@redhat.com>
>
> * gdbarch.c: Regenerate.
> * gdbarch.h: Regenerate.
> * gdbarch.sh (solib_file_not_found_is_ok): New.
> Include solib.h.
> * linux-tdep.c (linux_solib_file_not_found_is_ok): New function.
> (linux_init_abi): Install it.
> * solib.c (default_solib_file_not_found_is_ok): New function.
> (update_solib_list): New variable gdbarch. Substitute it for variable
> ops. Call gdbarch_solib_file_not_found_is_ok.
> * solib.h (default_solib_file_not_found_is_ok): New declaration.
>
> diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
> index 81a70b0..76f0ec9 100755
> --- a/gdb/gdbarch.sh
> +++ b/gdb/gdbarch.sh
> @@ -955,6 +955,10 @@ M:void:info_proc:char *args, enum info_proc_what what:args, what
> # inspected when the symbol search was requested.
> m:void:iterate_over_objfiles_in_search_order:iterate_over_objfiles_in_search_order_cb_ftype *cb, void *cb_data, struct objfile *current_objfile:cb, cb_data, current_objfile:0:default_iterate_over_objfiles_in_search_order::0
>
> +# Return non-zero if it is OK we failed to locate shared library file.
> +# For example these libraries may exist only in memory (vDSO).
> +f:int:solib_file_not_found_is_ok:const char *so_name:so_name:0:default_solib_file_not_found_is_ok::0
> +
> EOF
> }
>
> @@ -1411,6 +1415,7 @@ cat<<EOF
> #include "observer.h"
> #include "regcache.h"
> #include "objfiles.h"
> +#include "solib.h"
>
> /* Static function declarations */
>
> diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
> index dbeed36..c4f7bdd 100644
> --- a/gdb/linux-tdep.c
> +++ b/gdb/linux-tdep.c
> @@ -941,6 +941,17 @@ linux_make_corefile_notes_1 (struct gdbarch *gdbarch, bfd *obfd, int *note_size)
> linux_collect_thread_registers);
> }
>
> +/* Newer glibc no longer clears the Linux vDSO name to "" empty string. */
> +
> +static int
> +linux_solib_file_not_found_is_ok (const char *so_name)
> +{
> + return (strcmp (so_name, "linux-gate.so.1") == 0
> + || strcmp (so_name, "linux-vdso.so.1") == 0
> + || strcmp (so_name, "linux-vdso32.so.1") == 0
> + || strcmp (so_name, "linux-vdso64.so.1") == 0);
> +}
> +
> /* To be called from the various GDB_OSABI_LINUX handlers for the
> various GNU/Linux architectures and machine types. */
>
> @@ -953,6 +964,8 @@ linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
> set_gdbarch_make_corefile_notes (gdbarch, linux_make_corefile_notes_1);
> set_gdbarch_has_shared_address_space (gdbarch,
> linux_has_shared_address_space);
> + set_gdbarch_solib_file_not_found_is_ok (gdbarch,
> + linux_solib_file_not_found_is_ok);
> }
>
> /* Provide a prototype to silence -Wmissing-prototypes. */
> diff --git a/gdb/solib.c b/gdb/solib.c
> index db3842a..7976679 100644
> --- a/gdb/solib.c
> +++ b/gdb/solib.c
> @@ -642,6 +642,15 @@ solib_used (const struct so_list *const known)
> return 0;
> }
>
> +/* By default GDB complains on any missing shared library file via
> + gdbarch_solib_file_not_found_is_ok. */
> +
> +int
> +default_solib_file_not_found_is_ok (const char *so_name)
> +{
> + return 0;
> +}
> +
> /* Synchronize GDB's shared object list with inferior's.
>
> Extract the list of currently loaded shared objects from the
> @@ -668,7 +677,8 @@ solib_used (const struct so_list *const known)
> static void
> update_solib_list (int from_tty, struct target_ops *target)
> {
> - struct target_so_ops *ops = solib_ops (target_gdbarch ());
> + struct gdbarch *gdbarch = target_gdbarch ();
> + struct target_so_ops *ops = solib_ops (gdbarch);
> struct so_list *inferior = ops->current_sos();
> struct so_list *gdb, **gdb_link;
>
> @@ -798,7 +808,9 @@ update_solib_list (int from_tty, struct target_ops *target)
> TRY_CATCH (e, RETURN_MASK_ERROR)
> {
> /* Fill in the rest of the `struct so_list' node. */
> - if (!solib_map_sections (i))
> + if (!solib_map_sections (i)
> + && !gdbarch_solib_file_not_found_is_ok (gdbarch,
> + i->so_original_name))
> {
> not_found++;
> if (not_found_filename == NULL)
> diff --git a/gdb/solib.h b/gdb/solib.h
> index 7a2ff84..04510b8 100644
> --- a/gdb/solib.h
> +++ b/gdb/solib.h
> @@ -91,4 +91,6 @@ extern CORE_ADDR gdb_bfd_lookup_symbol_from_symtab (bfd *abfd,
> void *),
> void *data);
>
> +extern int default_solib_file_not_found_is_ok (const char *so_name);
> +
> #endif /* SOLIB_H */
>
Thansk for the patch.
I don't know about the others, but i find the name
"solib_not_found_is_ok" a little odd. What about "is_ignored_dso", or
"ignored_solib_p" or something in those veins?
What about linux-gate(32|64).so?
Regards,
Luis
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