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authorKees Cook <keescook@chromium.org>2022-12-01 16:23:25 -0800
committerKees Cook <keescook@chromium.org>2022-12-02 13:04:44 -0800
commitbdc77507fecd00ddad2f502f86a48a9ec38f0f84 (patch)
tree8c70f016ad598e4cbb9be00c31f405fbd3688b28
parent3a017d6355f24de42f2ad688df9fa19e0cb128f2 (diff)
downloadlinux-bdc77507fecd00ddad2f502f86a48a9ec38f0f84.tar.bz2
um: virt-pci: Avoid GCC non-NULL warning
GCC gets confused about the return value of get_cpu_var() possibly being NULL, so explicitly test for it before calls to memcpy() and memset(). Avoids warnings like this: arch/um/drivers/virt-pci.c: In function 'um_pci_send_cmd': include/linux/fortify-string.h:48:33: warning: argument 1 null where non-null expected [-Wnonnull] 48 | #define __underlying_memcpy __builtin_memcpy | ^ include/linux/fortify-string.h:438:9: note: in expansion of macro '__underlying_memcpy' 438 | __underlying_##op(p, q, __fortify_size); \ | ^~~~~~~~~~~~~ include/linux/fortify-string.h:483:26: note: in expansion of macro '__fortify_memcpy_chk' 483 | #define memcpy(p, q, s) __fortify_memcpy_chk(p, q, s, \ | ^~~~~~~~~~~~~~~~~~~~ arch/um/drivers/virt-pci.c:100:9: note: in expansion of macro 'memcpy' 100 | memcpy(buf, cmd, cmd_size); | ^~~~~~ While at it, avoid literal "8" and use stored sizeof(buf->data) in memset() and um_pci_send_cmd(). Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/lkml/202211271212.SUZSC9f9-lkp@intel.com Fixes: ba38961a069b ("um: Enable FORTIFY_SOURCE") Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Xiu Jianfeng <xiujianfeng@huawei.com> Cc: Vincent Whitchurch <vincent.whitchurch@axis.com> Cc: linux-um@lists.infradead.org Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
-rw-r--r--arch/um/drivers/virt-pci.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/um/drivers/virt-pci.c b/arch/um/drivers/virt-pci.c
index acb55b302b14..3ac220dafec4 100644
--- a/arch/um/drivers/virt-pci.c
+++ b/arch/um/drivers/virt-pci.c
@@ -97,7 +97,8 @@ static int um_pci_send_cmd(struct um_pci_device *dev,
}
buf = get_cpu_var(um_pci_msg_bufs);
- memcpy(buf, cmd, cmd_size);
+ if (buf)
+ memcpy(buf, cmd, cmd_size);
if (posted) {
u8 *ncmd = kmalloc(cmd_size + extra_size, GFP_ATOMIC);
@@ -182,6 +183,7 @@ static unsigned long um_pci_cfgspace_read(void *priv, unsigned int offset,
struct um_pci_message_buffer *buf;
u8 *data;
unsigned long ret = ULONG_MAX;
+ size_t bytes = sizeof(buf->data);
if (!dev)
return ULONG_MAX;
@@ -189,7 +191,8 @@ static unsigned long um_pci_cfgspace_read(void *priv, unsigned int offset,
buf = get_cpu_var(um_pci_msg_bufs);
data = buf->data;
- memset(buf->data, 0xff, sizeof(buf->data));
+ if (buf)
+ memset(data, 0xff, bytes);
switch (size) {
case 1:
@@ -204,7 +207,7 @@ static unsigned long um_pci_cfgspace_read(void *priv, unsigned int offset,
goto out;
}
- if (um_pci_send_cmd(dev, &hdr, sizeof(hdr), NULL, 0, data, 8))
+ if (um_pci_send_cmd(dev, &hdr, sizeof(hdr), NULL, 0, data, bytes))
goto out;
switch (size) {