The recent reordering of code in sev_ioctl_do_pdh_export triggered
a false-positive may-be-uninitialized warning from gcc:
In file included from ../include/linux/sched/task.h:13,
from ../include/linux/sched/signal.h:9,
from ../include/linux/rcuwait.h:6,
from ../include/linux/percpu-rwsem.h:7,
from ../include/linux/fs.h:34,
from ../include/linux/compat.h:17,
from ../arch/x86/include/asm/ia32.h:7,
from ../arch/x86/include/asm/elf.h:10,
from ../include/linux/elf.h:6,
from ../include/linux/module.h:19,
from ../drivers/crypto/ccp/sev-dev.c:11:
In function ‘copy_to_user’,
inlined from ‘sev_ioctl_do_pdh_export’ at ../drivers/crypto/ccp/sev-dev.c:2036:7,
inlined from ‘sev_ioctl’ at ../drivers/crypto/ccp/sev-dev.c:2249:9:
../include/linux/uaccess.h:225:16: warning: ‘input_cert_chain_address’ may be used uninitialized [-Wmaybe-uninitialized]
225 | return _copy_to_user(to, from, n);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
../drivers/crypto/ccp/sev-dev.c: In function ‘sev_ioctl’:
../drivers/crypto/ccp/sev-dev.c:1961:22: note: ‘input_cert_chain_address’ was declared here
1961 | void __user *input_cert_chain_address;
| ^~~~~~~~~~~~~~~~~~~~~~~~
Silence it by moving the initialisation of the variables in question
prior to the NULL check.
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 671347702ae7..c9ab4bd38d68 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -1968,15 +1968,15 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
memset(&data, 0, sizeof(data));
+ input_pdh_cert_address = (void __user *)input.pdh_cert_address;
+ input_cert_chain_address = (void __user *)input.cert_chain_address;
+
/* Userspace wants to query the certificate length. */
if (!input.pdh_cert_address ||
!input.pdh_cert_len ||
!input.cert_chain_address)
goto cmd;
- input_pdh_cert_address = (void __user *)input.pdh_cert_address;
- input_cert_chain_address = (void __user *)input.cert_chain_address;
-
/* Allocate a physically contiguous buffer to store the PDH blob. */
if (input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE)
return -EFAULT;
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
