Re: [PATCH] Fix infinite recursion bug at get_msymbol_address.

Ali Tamur via gdb-patches
2019-11-13T18:34:24Z

Friendly ping?

On Wed, Nov 6, 2019 at 8:05 PM Ali Tamur <tamur@google.com> wrote:

> The patch 4b610737f0 seems to have introduced the possibility of infinite
> recursion. I have encountered the problem while debugging a failing
> in-house
> test. I am sorry, it is fairly difficult to reduce the test case (and I
> don't
> understand most of what is going on) but the stack trace shows a call to
> objfpy_add_separate_debug_file, which eventually causes
> lookup_minimal_symbol_by_pc_name to be invoked, which calls
> get_msymbol_address.
> Somehow lookup_minimal_symbol_linkage finds the same symbol and the
> function
> calls itself with the same parameters. I don't know whether this should be
> classified as 'it should never happen', but this simple patch makes the
> test
> pass and should be harmless, I think.
>
> gdb/ChangeLog
>
> * symtab.c (get_msymbol_address): Guard against infinite recursion.
> ---
> gdb/symtab.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/gdb/symtab.c b/gdb/symtab.c
> index 2c934b9c22..b231cc6e84 100644
> --- a/gdb/symtab.c
> +++ b/gdb/symtab.c
> @@ -6328,7 +6328,7 @@ get_msymbol_address (struct objfile *objf, const
> struct minimal_symbol *minsym)
> {
> bound_minimal_symbol found
> = lookup_minimal_symbol_linkage (linkage_name, objfile);
> - if (found.minsym != nullptr)
> + if (found.minsym != nullptr && found.minsym != minsym)
> return BMSYMBOL_VALUE_ADDRESS (found);
> }
> }
> --
> 2.24.0.rc1.363.gb1bccd3e3d-goog
>
>