This is a note to let you know that I've just added the patch titled
bna: avoid writing uninitialized data into hw registers
to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: bna-avoid-writing-uninitialized-data-into-hw-registers.patch and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Thu Dec 21 10:35:49 CET 2017
From: Arnd Bergmann arnd@arndb.de Date: Thu, 23 Mar 2017 17:07:26 +0100 Subject: bna: avoid writing uninitialized data into hw registers
From: Arnd Bergmann arnd@arndb.de
[ Upstream commit a5af83925363eb85d467933e3d6ec5a87001eb7c ]
The latest gcc-7 snapshot warns about bfa_ioc_send_enable/bfa_ioc_send_disable writing undefined values into the hardware registers:
drivers/net/ethernet/brocade/bna/bfa_ioc.c: In function 'bfa_iocpf_sm_disabling_entry': arch/arm/include/asm/io.h:109:22: error: '*((void *)&disable_req+4)' is used uninitialized in this function [-Werror=uninitialized] arch/arm/include/asm/io.h:109:22: error: '*((void *)&disable_req+8)' is used uninitialized in this function [-Werror=uninitialized]
The two functions look like they should do the same thing, but only one of them initializes the time stamp and clscode field. The fact that we only get a warning for one of the two functions seems to be arbitrary, based on the inlining decisions in the compiler.
To address this, I'm making both functions do the same thing:
- set the clscode from the ioc structure in both - set the time stamp from ktime_get_real_seconds (which also avoids the signed-integer overflow in 2038 and extends the well-defined behavior until 2106). - zero-fill the reserved field
Fixes: 8b230ed8ec96 ("bna: Brocade 10Gb Ethernet device driver") Signed-off-by: Arnd Bergmann arnd@arndb.de Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/brocade/bna/bfa_ioc.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
--- a/drivers/net/ethernet/brocade/bna/bfa_ioc.c +++ b/drivers/net/ethernet/brocade/bna/bfa_ioc.c @@ -1930,13 +1930,13 @@ static void bfa_ioc_send_enable(struct bfa_ioc *ioc) { struct bfi_ioc_ctrl_req enable_req; - struct timeval tv;
bfi_h2i_set(enable_req.mh, BFI_MC_IOC, BFI_IOC_H2I_ENABLE_REQ, bfa_ioc_portid(ioc)); enable_req.clscode = htons(ioc->clscode); - do_gettimeofday(&tv); - enable_req.tv_sec = ntohl(tv.tv_sec); + enable_req.rsvd = htons(0); + /* overflow in 2106 */ + enable_req.tv_sec = ntohl(ktime_get_real_seconds()); bfa_ioc_mbox_send(ioc, &enable_req, sizeof(struct bfi_ioc_ctrl_req)); }
@@ -1947,6 +1947,10 @@ bfa_ioc_send_disable(struct bfa_ioc *ioc
bfi_h2i_set(disable_req.mh, BFI_MC_IOC, BFI_IOC_H2I_DISABLE_REQ, bfa_ioc_portid(ioc)); + disable_req.clscode = htons(ioc->clscode); + disable_req.rsvd = htons(0); + /* overflow in 2106 */ + disable_req.tv_sec = ntohl(ktime_get_real_seconds()); bfa_ioc_mbox_send(ioc, &disable_req, sizeof(struct bfi_ioc_ctrl_req)); }
Patches currently in stable-queue which might be from arnd@arndb.de are
queue-4.4/hwmon-asus_atk0110-fix-uninitialized-data-access.patch queue-4.4/arm-hide-finish_arch_post_lock_switch-from-modules.patch queue-4.4/bna-avoid-writing-uninitialized-data-into-hw-registers.patch queue-4.4/isdn-kcapi-avoid-uninitialized-data.patch