* Re: [axboe-block:for-6.10/io_uring 42/42] io_uring/register.c:175:24: warning: arithmetic between different enumeration types ('enum io_uring_register_restriction_op' and 'enum io_uring_register_op') [not found] <[email protected]> @ 2024-03-29 22:04 ` Gabriel Krisman Bertazi 2024-03-29 23:15 ` Jens Axboe 0 siblings, 1 reply; 3+ messages in thread From: Gabriel Krisman Bertazi @ 2024-03-29 22:04 UTC (permalink / raw) To: kernel test robot; +Cc: oe-kbuild-all, llvm, io-uring kernel test robot <[email protected]> writes: [+ io_uring list ] >>> io_uring/register.c:175:24: warning: arithmetic between different > enumeration types ('enum io_uring_register_restriction_op' and 'enum > io_uring_register_op') [-Wenum-enum-conversion] > 175 | if (!arg || nr_args > IORING_MAX_RESTRICTIONS) > | ^~~~~~~~~~~~~~~~~~~~~~~ > io_uring/register.c:31:58: note: expanded from macro 'IORING_MAX_RESTRICTIONS' > 31 | #define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \ > | ~~~~~~~~~~~~~~~~~~~~~~~ ^ > 32 | IORING_REGISTER_LAST + IORING_OP_LAST) > | ~~~~~~~~~~~~~~~~~~~~ > 14 warnings generated. hm. Do we want to fix? The arithmetic is safe here. I actually tried triggering the warning with gcc, but even with -Wenum-conversion in gcc-12 (which is in -Wextra and we don't use in the kernel build), I couldn't do it. only llvm catches this. can we explicit cast to int to silent it? -- Gabriel Krisman Bertazi ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [axboe-block:for-6.10/io_uring 42/42] io_uring/register.c:175:24: warning: arithmetic between different enumeration types ('enum io_uring_register_restriction_op' and 'enum io_uring_register_op') 2024-03-29 22:04 ` [axboe-block:for-6.10/io_uring 42/42] io_uring/register.c:175:24: warning: arithmetic between different enumeration types ('enum io_uring_register_restriction_op' and 'enum io_uring_register_op') Gabriel Krisman Bertazi @ 2024-03-29 23:15 ` Jens Axboe 2024-04-01 19:35 ` Nathan Chancellor 0 siblings, 1 reply; 3+ messages in thread From: Jens Axboe @ 2024-03-29 23:15 UTC (permalink / raw) To: Gabriel Krisman Bertazi, kernel test robot; +Cc: oe-kbuild-all, llvm, io-uring On 3/29/24 4:04 PM, Gabriel Krisman Bertazi wrote: > kernel test robot <[email protected]> writes: > > [+ io_uring list ] > >>>> io_uring/register.c:175:24: warning: arithmetic between different >> enumeration types ('enum io_uring_register_restriction_op' and 'enum >> io_uring_register_op') [-Wenum-enum-conversion] >> 175 | if (!arg || nr_args > IORING_MAX_RESTRICTIONS) >> | ^~~~~~~~~~~~~~~~~~~~~~~ >> io_uring/register.c:31:58: note: expanded from macro 'IORING_MAX_RESTRICTIONS' >> 31 | #define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \ >> | ~~~~~~~~~~~~~~~~~~~~~~~ ^ >> 32 | IORING_REGISTER_LAST + IORING_OP_LAST) >> | ~~~~~~~~~~~~~~~~~~~~ >> 14 warnings generated. > > hm. > > Do we want to fix? The arithmetic is safe here. I actually tried > triggering the warning with gcc, but even with -Wenum-conversion in > gcc-12 (which is in -Wextra and we don't use in the kernel build), I > couldn't do it. only llvm catches this. > > can we explicit cast to int to silent it? I don't think we care, there are others like it in the kernel already. Plus you need some magic warning incantation to hit it, clang by default is not going to be enough. -- Jens Axboe ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [axboe-block:for-6.10/io_uring 42/42] io_uring/register.c:175:24: warning: arithmetic between different enumeration types ('enum io_uring_register_restriction_op' and 'enum io_uring_register_op') 2024-03-29 23:15 ` Jens Axboe @ 2024-04-01 19:35 ` Nathan Chancellor 0 siblings, 0 replies; 3+ messages in thread From: Nathan Chancellor @ 2024-04-01 19:35 UTC (permalink / raw) To: Jens Axboe Cc: Gabriel Krisman Bertazi, kernel test robot, oe-kbuild-all, llvm, io-uring On Fri, Mar 29, 2024 at 05:15:44PM -0600, Jens Axboe wrote: > On 3/29/24 4:04 PM, Gabriel Krisman Bertazi wrote: > > kernel test robot <[email protected]> writes: > > > > [+ io_uring list ] > > > >>>> io_uring/register.c:175:24: warning: arithmetic between different > >> enumeration types ('enum io_uring_register_restriction_op' and 'enum > >> io_uring_register_op') [-Wenum-enum-conversion] > >> 175 | if (!arg || nr_args > IORING_MAX_RESTRICTIONS) > >> | ^~~~~~~~~~~~~~~~~~~~~~~ > >> io_uring/register.c:31:58: note: expanded from macro 'IORING_MAX_RESTRICTIONS' > >> 31 | #define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \ > >> | ~~~~~~~~~~~~~~~~~~~~~~~ ^ > >> 32 | IORING_REGISTER_LAST + IORING_OP_LAST) > >> | ~~~~~~~~~~~~~~~~~~~~ > >> 14 warnings generated. > > > > hm. > > > > Do we want to fix? The arithmetic is safe here. I actually tried > > triggering the warning with gcc, but even with -Wenum-conversion in > > gcc-12 (which is in -Wextra and we don't use in the kernel build), I > > couldn't do it. only llvm catches this. > > > > can we explicit cast to int to silent it? > > I don't think we care, there are others like it in the kernel already. > Plus you need some magic warning incantation to hit it, clang by default > is not going to be enough. The magic incantion would be W=1 after commit 75b5ab134bb5 ("kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1") but yes, there are plenty of other instances of this warning in the kernel and if the arithmetic is safe, ignoring the warning is perfectly fine in my opinion. The primary reason it is in W=1 rather than off by default is to see how many current instances may be bugs and see what new instances may pop up, as they may be unsafe conversions. We will have to come up with some way to annotate safe conversions if we want to turn this on by default (which is still being determined at this point). You do also have to have a tip of tree Clang to see this at the moment as well. Cheers, Nathan ^ permalink raw reply [flat|nested] 3+ messages in thread
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2024-03-29 22:04 ` [axboe-block:for-6.10/io_uring 42/42] io_uring/register.c:175:24: warning: arithmetic between different enumeration types ('enum io_uring_register_restriction_op' and 'enum io_uring_register_op') Gabriel Krisman Bertazi
2024-03-29 23:15 ` Jens Axboe
2024-04-01 19:35 ` Nathan Chancellor
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