Hi,
On Wed, May 01, 2024 at 06:06:18PM +0000, Edward Liaw wrote:
> Fixes clang compilation warnings by adding explicit unsigned conversion:
>
> parse_vdso.c:206:22: warning: passing 'const char *' to parameter of
> type 'const unsigned char *' converts between pointers to integer types
> where one is of the unique plain 'char' type and the other is not
> [-Wpointer-sign]
> ver_hash = elf_hash(version);
> ^~~~~~~
> parse_vdso.c:59:52: note: passing argument to parameter 'name' here
> static unsigned long elf_hash(const unsigned char *name)
> ^
> parse_vdso.c:207:46: warning: passing 'const char *' to parameter of
> type 'const unsigned char *' converts between pointers to integer types
> where one is of the unique plain 'char' type and the other is not
> [-Wpointer-sign]
> ELF(Word) chain = vdso_info.bucket[elf_hash(name) % vdso_info.nbucket];
> ^~~~
> parse_vdso.c:59:52: note: passing argument to parameter 'name' here
> static unsigned long elf_hash(const unsigned char *name)
>
> Fixes: 98eedc3a9dbf ("Document the vDSO and add a reference parser")
> Signed-off-by: Edward Liaw <edliaw@xxxxxxxxxx>
> ---
> v2: update commit message with correct compiler warning
> v3: fix checkpatch errors and indentation
> ---
> tools/testing/selftests/vDSO/parse_vdso.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/vDSO/parse_vdso.c b/tools/testing/selftests/vDSO/parse_vdso.c
> index 413f75620a35..9e29ff0657ea 100644
> --- a/tools/testing/selftests/vDSO/parse_vdso.c
> +++ b/tools/testing/selftests/vDSO/parse_vdso.c
> @@ -203,8 +203,9 @@ void *vdso_sym(const char *version, const char *name)
Is it possible to just change the types of the parameters of vdso_sym()
or does that trigger even more warnings on the callsites of vdso_sym()?
Either way, this looks ok to me.
Acked-by: Justin Stitt <justinstitt@xxxxxxxxxx>
> if (!vdso_info.valid)
> return 0;
>
> - ver_hash = elf_hash(version);
> - ELF(Word) chain = vdso_info.bucket[elf_hash(name) % vdso_info.nbucket];
> + ver_hash = elf_hash((const unsigned char *)version);
> + ELF(Word) chain = vdso_info.bucket[
> + elf_hash((const unsigned char *)name) % vdso_info.nbucket];
>
> for (; chain != STN_UNDEF; chain = vdso_info.chain[chain]) {
> ELF(Sym) *sym = &vdso_info.symtab[chain];
> --
> 2.45.0.rc0.197.gbae5840b3b-goog
>
Thanks
Justin
