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From:   Sven Schnelle <svens@linux.ibm.com>
To:     Shuah Khan <shuah@kernel.org>
Cc:     svens@stackframe.org, Thomas Gleixner <tglx@linutronix.de>,
        Steve Winslow <swinslow@gmail.com>,
        Alexios Zavras <alexios.zavras@intel.com>,
        Allison Randal <allison@lohutok.net>,
        linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
        Sven Schnelle <svens@linux.ibm.com>
Subject: [PATCH 1/2] selftests/vDSO: prevent SIGFPE if vdso_info.nbucket is zero
Date:   Sat,  4 Apr 2020 22:37:03 +0200
Message-Id: <20200404203704.69412-1-svens@linux.ibm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

If vdso_info can't be parsed correctly, vdso_info.nbucket might
contain zero. Add a check and return NULL which will fail the
symbol lookup.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
---
 tools/testing/selftests/vDSO/parse_vdso.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/vDSO/parse_vdso.c b/tools/testing/selftests/vDSO/parse_vdso.c
index 1dbb4b87268f..8e5a70a24d9a 100644
--- a/tools/testing/selftests/vDSO/parse_vdso.c
+++ b/tools/testing/selftests/vDSO/parse_vdso.c
@@ -226,6 +226,9 @@ void *vdso_sym(const char *version, const char *name)
 		return 0;
 
 	ver_hash = elf_hash(version);
+	if (!vdso_info.nbucket)
+		return NULL;
+
 	ELF(Word) chain = vdso_info.bucket[elf_hash(name) % vdso_info.nbucket];
 
 	for (; chain != STN_UNDEF; chain = vdso_info.chain[chain]) {
-- 
2.17.1