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From: Edward Liaw <edliaw@google.com>
To: linux-kernel@vger.kernel.org, Shuah Khan <shuah@kernel.org>,
	 Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	 Bill Wendling <morbo@google.com>,
	Justin Stitt <justinstitt@google.com>,
	 "H. Peter Anvin" <hpa@linux.intel.com>,
	Andy Lutomirski <luto@mit.edu>
Cc: linux-kselftest@vger.kernel.org, kernel-team@android.com,
	 Edward Liaw <edliaw@google.com>,
	llvm@lists.linux.dev
Subject: [PATCH v3] selftests/vDSO: Explicit unsigned char conversion for elf_hash
Date: Wed,  1 May 2024 18:06:18 +0000	[thread overview]
Message-ID: <20240501180622.1676340-1-edliaw@google.com> (raw)

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@google.com>
---
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)
 	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


             reply	other threads:[~2024-05-01 18:06 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-01 18:06 Edward Liaw [this message]
2024-05-01 19:54 ` [PATCH v3] selftests/vDSO: Explicit unsigned char conversion for elf_hash Justin Stitt
2024-05-01 20:21   ` Edward Liaw
2024-05-05 13:20   ` David Laight
2024-05-06 17:16     ` Justin Stitt
2024-05-06 17:34       ` Edward Liaw
2024-05-06 19:31         ` David Laight
2024-05-06 23:10           ` Edward Liaw

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