On Mon, Feb 17, 2025 at 02:04:18PM +0100, Thomas Weißschuh wrote:
Commit 14be4e6f3522 ("selftests: vDSO: fix ELF hash table entry size for s390x") changed the type of the ELF hash table entries to 64bit on s390x. However the *GNU* hash tables entries are always 32bit. The "bucket" pointer is shared between both hash algorithms.
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On s390x the GNU algorithm assigns and dereferences this pointer to a 64bit value as a pointer to a 32bit value, leading to compiler warnings and runtime crashes.
I would rephrase it as follows:
On s390, this caused the GNU hash algorithm to access its 32-bit entries as if they were 64-bit, triggering compiler warnings (assignment between "Elf64_Xword *" and "Elf64_Word *") and runtime crashes.
And take it via s390 tree.
Shuah, if you don't mind, may I get your Acked-by?
Thank you!
Introduce a new dedicated "gnu_bucket" pointer which is used by the GNU hash.
Fixes: e0746bde6f82 ("selftests/vDSO: support DT_GNU_HASH") Reviewed-by: Jens Remus jremus@linux.ibm.com Signed-off-by: Thomas Weißschuh thomas.weissschuh@linutronix.de
Changes in v2:
- Fix wording around the width of pointers vs the pointed-to values
- Link to v1: https://lore.kernel.org/r/20250213-selftests-vdso-s390-gnu-hash-v1-1-ace3bcc...
tools/testing/selftests/vDSO/parse_vdso.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)