* [PATCH] afs: correctly use 64-bit time for UUID @ 2017-01-11 13:44 Arnd Bergmann 2017-01-11 13:51 ` David Howells 0 siblings, 1 reply; 6+ messages in thread From: Arnd Bergmann @ 2017-01-11 13:44 UTC (permalink / raw) To: David Howells; +Cc: Tina Ruchandani, Arnd Bergmann, linux-afs, linux-kernel From: Tina Ruchandani <ruchandani.tina@gmail.com> UUID calculation uses 'struct timespec' whose seconds will overflow in year 2038 and beyond for 32-bit systems. This patch removes the dependency on 'struct timespec' by using ktime_get_real(). While the patch does not fix a 'bug' as such, it is part of a larger effort to remove instances of 'struct timespec' and other data-structures suffering from y2038 problem from the kernel. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- fs/afs/main.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/fs/afs/main.c b/fs/afs/main.c index f8188feb03ad..59e7ef38e541 100644 --- a/fs/afs/main.c +++ b/fs/afs/main.c @@ -13,6 +13,7 @@ #include <linux/moduleparam.h> #include <linux/init.h> #include <linux/completion.h> +#include <linux/ktime.h> #include <linux/sched.h> #include <linux/random.h> #define CREATE_TRACE_POINTS @@ -39,7 +40,6 @@ struct workqueue_struct *afs_wq; */ static int __init afs_get_client_UUID(void) { - struct timespec ts; u64 uuidtime; u16 clockseq; int ret; @@ -50,9 +50,7 @@ static int __init afs_get_client_UUID(void) if (ret < 0) return ret; - getnstimeofday(&ts); - uuidtime = (u64) ts.tv_sec * 1000 * 1000 * 10; - uuidtime += ts.tv_nsec / 100; + uuidtime = ktime_divns(ktime_get_real(), 100); uuidtime += AFS_UUID_TO_UNIX_TIME; afs_uuid.time_low = uuidtime; afs_uuid.time_mid = uuidtime >> 32; -- 2.9.0 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] afs: correctly use 64-bit time for UUID 2017-01-11 13:44 [PATCH] afs: correctly use 64-bit time for UUID Arnd Bergmann @ 2017-01-11 13:51 ` David Howells 2017-01-11 14:03 ` Arnd Bergmann 2017-01-11 14:47 ` David Howells 0 siblings, 2 replies; 6+ messages in thread From: David Howells @ 2017-01-11 13:51 UTC (permalink / raw) To: Arnd Bergmann; +Cc: dhowells, Tina Ruchandani, linux-afs, linux-kernel Arnd Bergmann <arnd@arndb.de> wrote: > From: Tina Ruchandani <ruchandani.tina@gmail.com> > > UUID calculation uses 'struct timespec' whose seconds will overflow > in year 2038 and beyond for 32-bit systems. This patch removes the > dependency on 'struct timespec' by using ktime_get_real(). > While the patch does not fix a 'bug' as such, it is part of a larger > effort to remove instances of 'struct timespec' and other data-structures > suffering from y2038 problem from the kernel. Is it worth abstracting out in-kernel UUID generation? David ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] afs: correctly use 64-bit time for UUID 2017-01-11 13:51 ` David Howells @ 2017-01-11 14:03 ` Arnd Bergmann 2017-01-11 14:47 ` David Howells 1 sibling, 0 replies; 6+ messages in thread From: Arnd Bergmann @ 2017-01-11 14:03 UTC (permalink / raw) To: David Howells; +Cc: Tina Ruchandani, linux-afs, linux-kernel On Wednesday, January 11, 2017 1:51:32 PM CET David Howells wrote: > Arnd Bergmann <arnd@arndb.de> wrote: > > > From: Tina Ruchandani <ruchandani.tina@gmail.com> > > > > UUID calculation uses 'struct timespec' whose seconds will overflow > > in year 2038 and beyond for 32-bit systems. This patch removes the > > dependency on 'struct timespec' by using ktime_get_real(). > > While the patch does not fix a 'bug' as such, it is part of a larger > > effort to remove instances of 'struct timespec' and other data-structures > > suffering from y2038 problem from the kernel. > > Is it worth abstracting out in-kernel UUID generation? Do you mean moving it out of AFS into lib/*.c? I think the 'afs_uuid' structure is quite different from other UUID definitions, so that wouldn't work. Arnd ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] afs: correctly use 64-bit time for UUID 2017-01-11 13:51 ` David Howells 2017-01-11 14:03 ` Arnd Bergmann @ 2017-01-11 14:47 ` David Howells 2017-01-11 15:55 ` Arnd Bergmann 1 sibling, 1 reply; 6+ messages in thread From: David Howells @ 2017-01-11 14:47 UTC (permalink / raw) To: Arnd Bergmann; +Cc: dhowells, Tina Ruchandani, linux-afs, linux-kernel Arnd Bergmann <arnd@arndb.de> wrote: > > Is it worth abstracting out in-kernel UUID generation? > > Do you mean moving it out of AFS into lib/*.c? I think the 'afs_uuid' > structure is quite different from other UUID definitions, so that wouldn't > work. afs_uuid is as it is to make it easier to package into the on-wire format, but I suspect there's no problem with using a completely random UUID instead and divvying it up the same way. David ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] afs: correctly use 64-bit time for UUID 2017-01-11 14:47 ` David Howells @ 2017-01-11 15:55 ` Arnd Bergmann 2017-01-12 9:27 ` [PATCH] afs: use random UUID kbuild test robot 0 siblings, 1 reply; 6+ messages in thread From: Arnd Bergmann @ 2017-01-11 15:55 UTC (permalink / raw) To: David Howells; +Cc: Tina Ruchandani, linux-afs, linux-kernel On Wednesday, January 11, 2017 2:47:20 PM CET David Howells wrote: > Arnd Bergmann <arnd@arndb.de> wrote: > > > > Is it worth abstracting out in-kernel UUID generation? > > > > Do you mean moving it out of AFS into lib/*.c? I think the 'afs_uuid' > > structure is quite different from other UUID definitions, so that wouldn't > > work. > > afs_uuid is as it is to make it easier to package into the on-wire format, but > I suspect there's no problem with using a completely random UUID instead and > divvying it up the same way. Maybe like this: 8<----7 >From 9e164f852366750fdd732ae317af9f4a9a04a16e Mon Sep 17 00:00:00 2001 From: Arnd Bergmann <arnd@arndb.de> Date: Wed, 11 Jan 2017 16:53:13 +0100 Subject: [PATCH] afs: use random UUID AFS uses a time based UUID to identify the host itself. This requires getting a timestamp which is currently done through the getnstimeofday() interface that we want to eventually get rid of. Instead of replacing it with a ktime based interface, this simply removes the entire function and uses generate_random_uuid() instead, which has a v4 ("completely random") uuid instead of the time based one. Signed-off-by: Arnd Bergmann <arnd@arndb.de> diff --git a/fs/afs/main.c b/fs/afs/main.c index f8188feb03ad..9944770849da 100644 --- a/fs/afs/main.c +++ b/fs/afs/main.c @@ -35,49 +35,6 @@ struct afs_uuid afs_uuid; struct workqueue_struct *afs_wq; /* - * get a client UUID - */ -static int __init afs_get_client_UUID(void) -{ - struct timespec ts; - u64 uuidtime; - u16 clockseq; - int ret; - - /* read the MAC address of one of the external interfaces and construct - * a UUID from it */ - ret = afs_get_MAC_address(afs_uuid.node, sizeof(afs_uuid.node)); - if (ret < 0) - return ret; - - getnstimeofday(&ts); - uuidtime = (u64) ts.tv_sec * 1000 * 1000 * 10; - uuidtime += ts.tv_nsec / 100; - uuidtime += AFS_UUID_TO_UNIX_TIME; - afs_uuid.time_low = uuidtime; - afs_uuid.time_mid = uuidtime >> 32; - afs_uuid.time_hi_and_version = (uuidtime >> 48) & AFS_UUID_TIMEHI_MASK; - afs_uuid.time_hi_and_version |= AFS_UUID_VERSION_TIME; - - get_random_bytes(&clockseq, 2); - afs_uuid.clock_seq_low = clockseq; - afs_uuid.clock_seq_hi_and_reserved = - (clockseq >> 8) & AFS_UUID_CLOCKHI_MASK; - afs_uuid.clock_seq_hi_and_reserved |= AFS_UUID_VARIANT_STD; - - _debug("AFS UUID: %08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x", - afs_uuid.time_low, - afs_uuid.time_mid, - afs_uuid.time_hi_and_version, - afs_uuid.clock_seq_hi_and_reserved, - afs_uuid.clock_seq_low, - afs_uuid.node[0], afs_uuid.node[1], afs_uuid.node[2], - afs_uuid.node[3], afs_uuid.node[4], afs_uuid.node[5]); - - return 0; -} - -/* * initialise the AFS client FS module */ static int __init afs_init(void) @@ -86,9 +43,7 @@ static int __init afs_init(void) printk(KERN_INFO "kAFS: Red Hat AFS client v0.1 registering.\n"); - ret = afs_get_client_UUID(); - if (ret < 0) - return ret; + generate_random_uuid((unsigned char *)&afs_uuid); /* create workqueue */ ret = -ENOMEM; ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] afs: use random UUID 2017-01-11 15:55 ` Arnd Bergmann @ 2017-01-12 9:27 ` kbuild test robot 0 siblings, 0 replies; 6+ messages in thread From: kbuild test robot @ 2017-01-12 9:27 UTC (permalink / raw) To: Arnd Bergmann Cc: kbuild-all, David Howells, Tina Ruchandani, linux-afs, linux-kernel [-- Attachment #1: Type: text/plain, Size: 1321 bytes --] Hi Arnd, [auto build test ERROR on linus/master] [also build test ERROR on v4.10-rc3 next-20170111] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Arnd-Bergmann/afs-use-random-UUID/20170112-153644 config: x86_64-randconfig-in0-01121653 (attached as .config) compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901 reproduce: # save the attached .config to linux build tree make ARCH=x86_64 All errors (new ones prefixed by >>): fs/afs/main.c: In function 'afs_init': >> fs/afs/main.c:45:2: error: implicit declaration of function 'generate_random_uuid' [-Werror=implicit-function-declaration] generate_random_uuid((unsigned char *)&afs_uuid); ^~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +/generate_random_uuid +45 fs/afs/main.c 39 static int __init afs_init(void) 40 { 41 int ret; 42 43 printk(KERN_INFO "kAFS: Red Hat AFS client v0.1 registering.\n"); 44 > 45 generate_random_uuid((unsigned char *)&afs_uuid); 46 47 /* create workqueue */ 48 ret = -ENOMEM; --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation [-- Attachment #2: .config.gz --] [-- Type: application/gzip, Size: 22103 bytes --] ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-01-12 9:27 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2017-01-11 13:44 [PATCH] afs: correctly use 64-bit time for UUID Arnd Bergmann 2017-01-11 13:51 ` David Howells 2017-01-11 14:03 ` Arnd Bergmann 2017-01-11 14:47 ` David Howells 2017-01-11 15:55 ` Arnd Bergmann 2017-01-12 9:27 ` [PATCH] afs: use random UUID kbuild test robot
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