Hi,
On Fri, Aug 02, 2024 at 07:38:07PM -0400, Aaron Merey wrote:
> From: Heather McIntyre <[email protected]>
>
> * libdw/libdw_findcu.c (__libdw_findcu): Add locking.
>
> Signed-off-by: Heather S. McIntyre <[email protected]>
> Signed-off-by: Aaron Merey <[email protected]>
> Signed-off-by: Mark Wielaard <[email protected]>
>
> ---
> v3 changes:
> Fix indentation and move rwlock_init calls to other patches in this
> series.
So this is basically a lock around __libdw_intern_next_unit. But there
is also a call to __libdw_intern_next_unit from dwarf_formref_die. So
there should also be a lock there?
> libdw/libdw_findcu.c | 38 +++++++++++++++++++++++++-------------
> 1 file changed, 25 insertions(+), 13 deletions(-)
>
> diff --git a/libdw/libdw_findcu.c b/libdw/libdw_findcu.c
> index c74e895e..bbbbee5d 100644
> --- a/libdw/libdw_findcu.c
> +++ b/libdw/libdw_findcu.c
> @@ -245,27 +245,39 @@ __libdw_findcu (Dwarf *dbg, Dwarf_Off start, bool
> v4_debug_types)
> /* Maybe we already know that CU. */
> struct Dwarf_CU fake = { .start = start, .end = 0 };
> struct Dwarf_CU **found = eu_tfind (&fake, tree, findcu_cb);
> + struct Dwarf_CU *result = NULL;
> if (found != NULL)
> return *found;
>
> + rwlock_wrlock (dbg->dwarf_lock);
> +
> if (start < *next_offset)
> + __libdw_seterrno (DWARF_E_INVALID_DWARF);
> + else
> {
> - __libdw_seterrno (DWARF_E_INVALID_DWARF);
> - return NULL;
> - }
> + /* No. Then read more CUs. */
> + while (1)
> + {
> + struct Dwarf_CU *newp
> + = __libdw_intern_next_unit (dbg, v4_debug_types);
>
> - /* No. Then read more CUs. */
> - while (1)
> - {
> - struct Dwarf_CU *newp = __libdw_intern_next_unit (dbg, v4_debug_types);
> - if (newp == NULL)
> - return NULL;
> + if (newp == NULL)
> + {
> + result = NULL;
> + break;
> + }
>
> - /* Is this the one we are looking for? */
> - if (start < *next_offset || start == newp->start)
> - return newp;
> + /* Is this the one we are looking for? */
> + if (start < *next_offset || start == newp->start)
> + {
> + result = newp;
> + break;
> + }
> + }
> }
> - /* NOTREACHED */
> +
> + rwlock_unlock (dbg->dwarf_lock);
> + return result;
> }
>
> struct Dwarf_CU *
> --
> 2.45.2
>
