* Re: [LTP] [PATCH] sysctl03: sysctl returns EACCES after 2.6.33-rc1 [not found] ` <4B8F716E.5070207@cn.fujitsu.com> @ 2010-03-04 18:35 ` Garrett Cooper 2010-03-04 18:37 ` Garrett Cooper 1 sibling, 0 replies; 5+ messages in thread From: Garrett Cooper @ 2010-03-04 18:35 UTC (permalink / raw) To: Shi Weihua; +Cc: Rishikesh K Rajak, LTP, linux-kernel, ebiederm On Thu, Mar 4, 2010 at 12:38 AM, Shi Weihua <shiwh@cn.fujitsu.com> wrote: > at 2010-2-25 9:18, Garrett Cooper wrote: >> On Mon, Feb 22, 2010 at 5:48 PM, Shi Weihua <shiwh@cn.fujitsu.com> wrote: >>> at 2010-2-22 15:44, Garrett Cooper wrote: >>>> Ok.. one last thing. >>>> >>>> On Sun, Feb 21, 2010 at 11:15 PM, Shi Weihua <shiwh@cn.fujitsu.com> wrote: >>>>> at 2010-2-18 12:25, Rishikesh K Rajak wrote: >>>>>> On Wed, Feb 17, 2010 at 09:10:48AM -0800, Garrett Cooper wrote: >>>>>>> On Wed, Feb 17, 2010 at 12:01 AM, Rishikesh <risrajak@linux.vnet.ibm.com> wrote: >>>>>>>> Hi Shi, >>>>>>>> >>>>>>>> Thanks for your patch, still i am finding time to look into your patch. >>>>>>>> Will reply you soon. >>>>>>>> >>>>>>>> http://marc.info/?l=ltp-list&m=126502355614857&w=2 >>>>>>> >>>>>>> I looked at the patch finally. >>>>>> >>>>>> Thanks garret. >>>>>>> >>>>>>> Please use TTERRNO instead of strerror(...) for the reported value. >>>>>>> There's no reason why you should use strerror(...) there as that's >>>>>>> already done with tst_res(3). >>>>>> >>>>>> Shi, can you please incorporate changes which garret has suggested and >>>>>> resend the patch again to ltp-list@ . >>>>> >>>>> Ok, i recreated the patch based on garret's suggestion. >>>>> >>>>> Signed-off-by: Shi Weihua <shiwh@cn.fujitsu.com> >>>>> --- >>>>> --- testcases/kernel/syscalls/sysctl/sysctl03.c.orig 2010-02-22 14:38:26.000000000 -0500 >>>>> +++ testcases/kernel/syscalls/sysctl/sysctl03.c 2010-02-22 15:08:03.000000000 -0500 >>>>> @@ -22,15 +22,18 @@ >>>>> * sysctl03.c >>>>> * >>>>> * DESCRIPTION >>>>> - * Testcase to check that sysctl(2) sets errno to EPERM correctly. >>>>> + * Testcase to check that sysctl(2) sets errno to EPERM or EACCES >>>>> + * correctly. But it will return EACCES on kernels that are 2.6.33-rc1 >>>>> + * and higher. >>>>> * >>>>> * ALGORITHM >>>>> * a. Call sysctl(2) as a root user, and attempt to write data >>>>> * to the kernel_table[]. Since the table does not have write >>>>> - * permissions even for the root, it should fail EPERM. >>>>> + * permissions even for the root, it should fail EPERM or EACCES. >>>>> * b. Call sysctl(2) as a non-root user, and attempt to write data >>>>> * to the kernel_table[]. Since the table does not have write >>>>> - * permission for the regular user, it should fail with EPERM. >>>>> + * permission for the regular user, it should fail with EPERM >>>>> + * or EACCES. >>>>> * >>>>> * USAGE: <for command-line> >>>>> * sysctl03 [-c n] [-e] [-i n] [-I x] [-P x] [-t] >>>>> @@ -43,6 +46,7 @@ >>>>> * >>>>> * HISTORY >>>>> * 07/2001 Ported by Wayne Boyer >>>>> + * 02/2010 Updated by shiwh@cn.fujitsu.com >>>>> * >>>>> * RESTRICTIONS >>>>> * Test must be run as root. >>>>> @@ -82,6 +86,7 @@ int main(int ac, char **av) >>>>> { >>>>> int lc; >>>>> char *msg; >>>>> + int exp_eno; >>>>> >>>>> char osname[OSNAMESZ]; >>>>> int osnamelth, status; >>>>> @@ -96,6 +101,13 @@ int main(int ac, char **av) >>>>> >>>>> setup(); >>>>> >>>>> + if ((tst_kvercmp(2, 6, 32)) <= 0){ >>>>> + exp_eno = EPERM; >>>>> + } else { >>>>> + exp_eno = EACCES; >>>>> + exp_enos[0] = EACCES; >>>>> + } >>>>> + >>>>> TEST_EXP_ENOS(exp_enos); >>>>> >>>>> /* check looping state if -i option is given */ >>>>> @@ -114,13 +126,10 @@ int main(int ac, char **av) >>>>> } else { >>>>> TEST_ERROR_LOG(TEST_ERRNO); >>>>> >>>>> - if (TEST_ERRNO != EPERM) { >>>>> - tst_resm(TFAIL, >>>>> - "Expected EPERM (%d), got %d: %s", >>>>> - EPERM, TEST_ERRNO, >>>>> - strerror(TEST_ERRNO)); >>>>> + if (TEST_ERRNO != exp_eno) { >>>>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error"); >>>>> } else { >>>>> - tst_resm(TPASS, "Got expected EPERM error"); >>>>> + tst_resm(TPASS|TTERRNO, "Got expected error"); >>>>> } >>>>> } >>>>> >>>>> @@ -147,12 +156,10 @@ int main(int ac, char **av) >>>>> } else { >>>>> TEST_ERROR_LOG(TEST_ERRNO); >>>>> >>>>> - if (TEST_ERRNO != EPERM) { >>>>> - tst_resm(TFAIL, "Expected EPERM, got " >>>>> - "%d", TEST_ERRNO); >>>>> + if (TEST_ERRNO != exp_eno) { >>>> >>>> Why can't this be exp_enos[0] ? >>> >>> Using exp_enos[0] is ok. pls check the latest patch in this mail. >>> >>>> >>>>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error"); >>>> >>>> Typo. >>>> >>>>> } else { >>>>> - tst_resm(TPASS, "Got expected EPERM " >>>>> - "error"); >>>>> + tst_resm(TPASS|TTERRNO, "Got expected error"); >>>>> } >>>>> } >>>>> >>>>> >>>>> Thank you. >>>>> - Shi Weihua >>>> >>>> It always helps to understand what's expected vs unexpected >>>> without having to look at the source code. Could you please revise the >>>> tst_resm format strings to be something like the following? >>>> >>>> tst_resm (TPASS | TERRNO, "Got expected error (errno = %d, ret_code = >>>> %d", exp_errno_blah, exp_ret_code_blah); >>>> >>>> OR: >>>> >>>> tst_resm (TPASS | TERRNO, "Got unexpected error (expected errno = %d, >>>> ret_code = %d - got errno = %d, ret_code = %d", exp_errno_blah, >>>> exp_ret_code_blah, errno_blah, ret_code_blah); >>> >>> ret_code has not been defined in sysctl03.c, i think it's unnecessarily to >>> import a new parameter. maybe, we can use your macro when it created. ;-) >>> >>> --- testcases/kernel/syscalls/sysctl/sysctl03.c.orig 2010-02-22 14:38:26.000000000 -0500 >>> +++ testcases/kernel/syscalls/sysctl/sysctl03.c 2010-02-23 09:35:20.000000000 -0500 >>> @@ -22,15 +22,18 @@ >>> * sysctl03.c >>> * >>> * DESCRIPTION >>> - * Testcase to check that sysctl(2) sets errno to EPERM correctly. >>> + * Testcase to check that sysctl(2) sets errno to EPERM or EACCES >>> + * correctly. But it will return EACCES on kernels that are 2.6.33-rc1 >>> + * and higher. >>> * >>> * ALGORITHM >>> * a. Call sysctl(2) as a root user, and attempt to write data >>> * to the kernel_table[]. Since the table does not have write >>> - * permissions even for the root, it should fail EPERM. >>> + * permissions even for the root, it should fail EPERM or EACCES. >>> * b. Call sysctl(2) as a non-root user, and attempt to write data >>> * to the kernel_table[]. Since the table does not have write >>> - * permission for the regular user, it should fail with EPERM. >>> + * permission for the regular user, it should fail with EPERM >>> + * or EACCES. >>> * >>> * USAGE: <for command-line> >>> * sysctl03 [-c n] [-e] [-i n] [-I x] [-P x] [-t] >>> @@ -43,6 +46,7 @@ >>> * >>> * HISTORY >>> * 07/2001 Ported by Wayne Boyer >>> + * 02/2010 Updated by shiwh@cn.fujitsu.com >>> * >>> * RESTRICTIONS >>> * Test must be run as root. >>> @@ -96,6 +100,12 @@ int main(int ac, char **av) >>> >>> setup(); >>> >>> + if ((tst_kvercmp(2, 6, 32)) <= 0){ >>> + exp_enos[0] = EPERM; >>> + } else { >>> + exp_enos[0] = EACCES; >>> + } >>> + >>> TEST_EXP_ENOS(exp_enos); >>> >>> /* check looping state if -i option is given */ >>> @@ -114,13 +124,12 @@ int main(int ac, char **av) >>> } else { >>> TEST_ERROR_LOG(TEST_ERRNO); >>> >>> - if (TEST_ERRNO != EPERM) { >>> - tst_resm(TFAIL, >>> - "Expected EPERM (%d), got %d: %s", >>> - EPERM, TEST_ERRNO, >>> - strerror(TEST_ERRNO)); >>> + if (TEST_ERRNO != exp_enos[0]) { >>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error " >>> + "(expected error = %d)", exp_enos[0]); >>> } else { >>> - tst_resm(TPASS, "Got expected EPERM error"); >>> + tst_resm(TPASS|TTERRNO, "Got expected error " >>> + "(errno = %d)", exp_enos[0]); >>> } >>> } >>> >>> @@ -147,12 +156,12 @@ int main(int ac, char **av) >>> } else { >>> TEST_ERROR_LOG(TEST_ERRNO); >>> >>> - if (TEST_ERRNO != EPERM) { >>> - tst_resm(TFAIL, "Expected EPERM, got " >>> - "%d", TEST_ERRNO); >>> + if (TEST_ERRNO != exp_enos[0]) { >>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error " >>> + "(expected error = %d)", exp_enos[0]); >>> } else { >>> - tst_resm(TPASS, "Got expected EPERM " >>> - "error"); >>> + tst_resm(TPASS|TTERRNO, "Got expected error " >>> + "(errno = %d)", exp_enos[0]); >>> } >>> } >> >> Ok, before I go and commit this, there are two things I need to know >> (because trusty Google didn't turn up any results for this behavioral >> change): >> >> 1. The change is legitimate. >> 2. The documentation is up to date, or a bug has been filed for the >> documentation change. >> >> If you can provide these two things, I'll commit the change. > > At this time of day, I can not find any documentation about EPERM->EACCES. > But, i caught the kernel commit which caused ltp bug: > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=26a7034b40ba80f82f64fa251a2cbf49f9971c6a > Maybe it can help you to judge. Wow... that's a fair amount of code refactoring and additions to the syscall. Yes, all of the issues with opening a directory and reading/writing now apply to sysctl(2), especially if someone attempts to read from a write-only descriptor, or vice versa. I hate to do this in such a reactive manner as this should have been done up front, but the 1) documentation and 2) test need to be updated. 1) is more key today because I'm not sure how much testing the developer did before he committed to kernel.org, but without updated documentation and requirements we can't write proper tests. Thanks, -Garrett ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [LTP] [PATCH] sysctl03: sysctl returns EACCES after 2.6.33-rc1 [not found] ` <4B8F716E.5070207@cn.fujitsu.com> 2010-03-04 18:35 ` [LTP] [PATCH] sysctl03: sysctl returns EACCES after 2.6.33-rc1 Garrett Cooper @ 2010-03-04 18:37 ` Garrett Cooper 2010-03-04 19:57 ` Eric W. Biederman 1 sibling, 1 reply; 5+ messages in thread From: Garrett Cooper @ 2010-03-04 18:37 UTC (permalink / raw) To: Shi Weihua; +Cc: Rishikesh K Rajak, LTP, linux-kernel, ebiederm On Thu, Mar 4, 2010 at 12:38 AM, Shi Weihua <shiwh@cn.fujitsu.com> wrote: > at 2010-2-25 9:18, Garrett Cooper wrote: >> On Mon, Feb 22, 2010 at 5:48 PM, Shi Weihua <shiwh@cn.fujitsu.com> wrote: >>> at 2010-2-22 15:44, Garrett Cooper wrote: >>>> Ok.. one last thing. >>>> >>>> On Sun, Feb 21, 2010 at 11:15 PM, Shi Weihua <shiwh@cn.fujitsu.com> wrote: >>>>> at 2010-2-18 12:25, Rishikesh K Rajak wrote: >>>>>> On Wed, Feb 17, 2010 at 09:10:48AM -0800, Garrett Cooper wrote: >>>>>>> On Wed, Feb 17, 2010 at 12:01 AM, Rishikesh <risrajak@linux.vnet.ibm.com> wrote: >>>>>>>> Hi Shi, >>>>>>>> >>>>>>>> Thanks for your patch, still i am finding time to look into your patch. >>>>>>>> Will reply you soon. >>>>>>>> >>>>>>>> http://marc.info/?l=ltp-list&m=126502355614857&w=2 >>>>>>> >>>>>>> I looked at the patch finally. >>>>>> >>>>>> Thanks garret. >>>>>>> >>>>>>> Please use TTERRNO instead of strerror(...) for the reported value. >>>>>>> There's no reason why you should use strerror(...) there as that's >>>>>>> already done with tst_res(3). >>>>>> >>>>>> Shi, can you please incorporate changes which garret has suggested and >>>>>> resend the patch again to ltp-list@ . >>>>> >>>>> Ok, i recreated the patch based on garret's suggestion. >>>>> >>>>> Signed-off-by: Shi Weihua <shiwh@cn.fujitsu.com> >>>>> --- >>>>> --- testcases/kernel/syscalls/sysctl/sysctl03.c.orig 2010-02-22 14:38:26.000000000 -0500 >>>>> +++ testcases/kernel/syscalls/sysctl/sysctl03.c 2010-02-22 15:08:03.000000000 -0500 >>>>> @@ -22,15 +22,18 @@ >>>>> * sysctl03.c >>>>> * >>>>> * DESCRIPTION >>>>> - * Testcase to check that sysctl(2) sets errno to EPERM correctly. >>>>> + * Testcase to check that sysctl(2) sets errno to EPERM or EACCES >>>>> + * correctly. But it will return EACCES on kernels that are 2.6.33-rc1 >>>>> + * and higher. >>>>> * >>>>> * ALGORITHM >>>>> * a. Call sysctl(2) as a root user, and attempt to write data >>>>> * to the kernel_table[]. Since the table does not have write >>>>> - * permissions even for the root, it should fail EPERM. >>>>> + * permissions even for the root, it should fail EPERM or EACCES. >>>>> * b. Call sysctl(2) as a non-root user, and attempt to write data >>>>> * to the kernel_table[]. Since the table does not have write >>>>> - * permission for the regular user, it should fail with EPERM. >>>>> + * permission for the regular user, it should fail with EPERM >>>>> + * or EACCES. >>>>> * >>>>> * USAGE: <for command-line> >>>>> * sysctl03 [-c n] [-e] [-i n] [-I x] [-P x] [-t] >>>>> @@ -43,6 +46,7 @@ >>>>> * >>>>> * HISTORY >>>>> * 07/2001 Ported by Wayne Boyer >>>>> + * 02/2010 Updated by shiwh@cn.fujitsu.com >>>>> * >>>>> * RESTRICTIONS >>>>> * Test must be run as root. >>>>> @@ -82,6 +86,7 @@ int main(int ac, char **av) >>>>> { >>>>> int lc; >>>>> char *msg; >>>>> + int exp_eno; >>>>> >>>>> char osname[OSNAMESZ]; >>>>> int osnamelth, status; >>>>> @@ -96,6 +101,13 @@ int main(int ac, char **av) >>>>> >>>>> setup(); >>>>> >>>>> + if ((tst_kvercmp(2, 6, 32)) <= 0){ >>>>> + exp_eno = EPERM; >>>>> + } else { >>>>> + exp_eno = EACCES; >>>>> + exp_enos[0] = EACCES; >>>>> + } >>>>> + >>>>> TEST_EXP_ENOS(exp_enos); >>>>> >>>>> /* check looping state if -i option is given */ >>>>> @@ -114,13 +126,10 @@ int main(int ac, char **av) >>>>> } else { >>>>> TEST_ERROR_LOG(TEST_ERRNO); >>>>> >>>>> - if (TEST_ERRNO != EPERM) { >>>>> - tst_resm(TFAIL, >>>>> - "Expected EPERM (%d), got %d: %s", >>>>> - EPERM, TEST_ERRNO, >>>>> - strerror(TEST_ERRNO)); >>>>> + if (TEST_ERRNO != exp_eno) { >>>>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error"); >>>>> } else { >>>>> - tst_resm(TPASS, "Got expected EPERM error"); >>>>> + tst_resm(TPASS|TTERRNO, "Got expected error"); >>>>> } >>>>> } >>>>> >>>>> @@ -147,12 +156,10 @@ int main(int ac, char **av) >>>>> } else { >>>>> TEST_ERROR_LOG(TEST_ERRNO); >>>>> >>>>> - if (TEST_ERRNO != EPERM) { >>>>> - tst_resm(TFAIL, "Expected EPERM, got " >>>>> - "%d", TEST_ERRNO); >>>>> + if (TEST_ERRNO != exp_eno) { >>>> >>>> Why can't this be exp_enos[0] ? >>> >>> Using exp_enos[0] is ok. pls check the latest patch in this mail. >>> >>>> >>>>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error"); >>>> >>>> Typo. >>>> >>>>> } else { >>>>> - tst_resm(TPASS, "Got expected EPERM " >>>>> - "error"); >>>>> + tst_resm(TPASS|TTERRNO, "Got expected error"); >>>>> } >>>>> } >>>>> >>>>> >>>>> Thank you. >>>>> - Shi Weihua >>>> >>>> It always helps to understand what's expected vs unexpected >>>> without having to look at the source code. Could you please revise the >>>> tst_resm format strings to be something like the following? >>>> >>>> tst_resm (TPASS | TERRNO, "Got expected error (errno = %d, ret_code = >>>> %d", exp_errno_blah, exp_ret_code_blah); >>>> >>>> OR: >>>> >>>> tst_resm (TPASS | TERRNO, "Got unexpected error (expected errno = %d, >>>> ret_code = %d - got errno = %d, ret_code = %d", exp_errno_blah, >>>> exp_ret_code_blah, errno_blah, ret_code_blah); >>> >>> ret_code has not been defined in sysctl03.c, i think it's unnecessarily to >>> import a new parameter. maybe, we can use your macro when it created. ;-) >>> >>> --- testcases/kernel/syscalls/sysctl/sysctl03.c.orig 2010-02-22 14:38:26.000000000 -0500 >>> +++ testcases/kernel/syscalls/sysctl/sysctl03.c 2010-02-23 09:35:20.000000000 -0500 >>> @@ -22,15 +22,18 @@ >>> * sysctl03.c >>> * >>> * DESCRIPTION >>> - * Testcase to check that sysctl(2) sets errno to EPERM correctly. >>> + * Testcase to check that sysctl(2) sets errno to EPERM or EACCES >>> + * correctly. But it will return EACCES on kernels that are 2.6.33-rc1 >>> + * and higher. >>> * >>> * ALGORITHM >>> * a. Call sysctl(2) as a root user, and attempt to write data >>> * to the kernel_table[]. Since the table does not have write >>> - * permissions even for the root, it should fail EPERM. >>> + * permissions even for the root, it should fail EPERM or EACCES. >>> * b. Call sysctl(2) as a non-root user, and attempt to write data >>> * to the kernel_table[]. Since the table does not have write >>> - * permission for the regular user, it should fail with EPERM. >>> + * permission for the regular user, it should fail with EPERM >>> + * or EACCES. >>> * >>> * USAGE: <for command-line> >>> * sysctl03 [-c n] [-e] [-i n] [-I x] [-P x] [-t] >>> @@ -43,6 +46,7 @@ >>> * >>> * HISTORY >>> * 07/2001 Ported by Wayne Boyer >>> + * 02/2010 Updated by shiwh@cn.fujitsu.com >>> * >>> * RESTRICTIONS >>> * Test must be run as root. >>> @@ -96,6 +100,12 @@ int main(int ac, char **av) >>> >>> setup(); >>> >>> + if ((tst_kvercmp(2, 6, 32)) <= 0){ >>> + exp_enos[0] = EPERM; >>> + } else { >>> + exp_enos[0] = EACCES; >>> + } >>> + >>> TEST_EXP_ENOS(exp_enos); >>> >>> /* check looping state if -i option is given */ >>> @@ -114,13 +124,12 @@ int main(int ac, char **av) >>> } else { >>> TEST_ERROR_LOG(TEST_ERRNO); >>> >>> - if (TEST_ERRNO != EPERM) { >>> - tst_resm(TFAIL, >>> - "Expected EPERM (%d), got %d: %s", >>> - EPERM, TEST_ERRNO, >>> - strerror(TEST_ERRNO)); >>> + if (TEST_ERRNO != exp_enos[0]) { >>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error " >>> + "(expected error = %d)", exp_enos[0]); >>> } else { >>> - tst_resm(TPASS, "Got expected EPERM error"); >>> + tst_resm(TPASS|TTERRNO, "Got expected error " >>> + "(errno = %d)", exp_enos[0]); >>> } >>> } >>> >>> @@ -147,12 +156,12 @@ int main(int ac, char **av) >>> } else { >>> TEST_ERROR_LOG(TEST_ERRNO); >>> >>> - if (TEST_ERRNO != EPERM) { >>> - tst_resm(TFAIL, "Expected EPERM, got " >>> - "%d", TEST_ERRNO); >>> + if (TEST_ERRNO != exp_enos[0]) { >>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error " >>> + "(expected error = %d)", exp_enos[0]); >>> } else { >>> - tst_resm(TPASS, "Got expected EPERM " >>> - "error"); >>> + tst_resm(TPASS|TTERRNO, "Got expected error " >>> + "(errno = %d)", exp_enos[0]); >>> } >>> } >> >> Ok, before I go and commit this, there are two things I need to know >> (because trusty Google didn't turn up any results for this behavioral >> change): >> >> 1. The change is legitimate. >> 2. The documentation is up to date, or a bug has been filed for the >> documentation change. >> >> If you can provide these two things, I'll commit the change. > > At this time of day, I can not find any documentation about EPERM->EACCES. > But, i caught the kernel commit which caused ltp bug: > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=26a7034b40ba80f82f64fa251a2cbf49f9971c6a > Maybe it can help you to judge. Wow... that's a fair amount of code refactoring and additions to the syscall. Yes, all of the issues with opening a directory and reading/writing now apply to sysctl(2), especially if someone attempts to read from a write-only descriptor, or vice versa. I hate to do this in such a reactive manner as this should have been done up front, but the 1) documentation and 2) test need to be updated. 1) is more key today because I'm not sure how much testing the developer did before he committed to kernel.org, but without updated documentation and requirements we can't write proper tests. Thanks, -Garrett ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [LTP] [PATCH] sysctl03: sysctl returns EACCES after 2.6.33-rc1 2010-03-04 18:37 ` Garrett Cooper @ 2010-03-04 19:57 ` Eric W. Biederman 2010-03-05 7:20 ` Garrett Cooper 0 siblings, 1 reply; 5+ messages in thread From: Eric W. Biederman @ 2010-03-04 19:57 UTC (permalink / raw) To: Garrett Cooper; +Cc: Shi Weihua, Rishikesh K Rajak, LTP, linux-kernel Garrett Cooper <yanegomi@gmail.com> writes: > On Thu, Mar 4, 2010 at 12:38 AM, Shi Weihua <shiwh@cn.fujitsu.com> wrote: >> at 2010-2-25 9:18, Garrett Cooper wrote: >>> On Mon, Feb 22, 2010 at 5:48 PM, Shi Weihua <shiwh@cn.fujitsu.com> wrote: >>>> at 2010-2-22 15:44, Garrett Cooper wrote: >>>>> Ok.. one last thing. >>>>> >>>>> On Sun, Feb 21, 2010 at 11:15 PM, Shi Weihua <shiwh@cn.fujitsu.com> wrote: >>>>>> at 2010-2-18 12:25, Rishikesh K Rajak wrote: >>>>>>> On Wed, Feb 17, 2010 at 09:10:48AM -0800, Garrett Cooper wrote: >>>>>>>> On Wed, Feb 17, 2010 at 12:01 AM, Rishikesh <risrajak@linux.vnet.ibm.com> wrote: >>>>>>>>> Hi Shi, >>>>>>>>> >>>>>>>>> Thanks for your patch, still i am finding time to look into your patch. >>>>>>>>> Will reply you soon. >>>>>>>>> >>>>>>>>> http://marc.info/?l=ltp-list&m=126502355614857&w=2 >>>>>>>> >>>>>>>> I looked at the patch finally. >>>>>>> >>>>>>> Thanks garret. >>>>>>>> >>>>>>>> Please use TTERRNO instead of strerror(...) for the reported value. >>>>>>>> There's no reason why you should use strerror(...) there as that's >>>>>>>> already done with tst_res(3). >>>>>>> >>>>>>> Shi, can you please incorporate changes which garret has suggested and >>>>>>> resend the patch again to ltp-list@ . >>>>>> >>>>>> Ok, i recreated the patch based on garret's suggestion. >>>>>> >>>>>> Signed-off-by: Shi Weihua <shiwh@cn.fujitsu.com> >>>>>> --- >>>>>> --- testcases/kernel/syscalls/sysctl/sysctl03.c.orig 2010-02-22 14:38:26.000000000 -0500 >>>>>> +++ testcases/kernel/syscalls/sysctl/sysctl03.c 2010-02-22 15:08:03.000000000 -0500 >>>>>> @@ -22,15 +22,18 @@ >>>>>> * sysctl03.c >>>>>> * >>>>>> * DESCRIPTION >>>>>> - * Testcase to check that sysctl(2) sets errno to EPERM correctly. >>>>>> + * Testcase to check that sysctl(2) sets errno to EPERM or EACCES >>>>>> + * correctly. But it will return EACCES on kernels that are 2.6.33-rc1 >>>>>> + * and higher. >>>>>> * >>>>>> * ALGORITHM >>>>>> * a. Call sysctl(2) as a root user, and attempt to write data >>>>>> * to the kernel_table[]. Since the table does not have write >>>>>> - * permissions even for the root, it should fail EPERM. >>>>>> + * permissions even for the root, it should fail EPERM or EACCES. >>>>>> * b. Call sysctl(2) as a non-root user, and attempt to write data >>>>>> * to the kernel_table[]. Since the table does not have write >>>>>> - * permission for the regular user, it should fail with EPERM. >>>>>> + * permission for the regular user, it should fail with EPERM >>>>>> + * or EACCES. >>>>>> * >>>>>> * USAGE: <for command-line> >>>>>> * sysctl03 [-c n] [-e] [-i n] [-I x] [-P x] [-t] >>>>>> @@ -43,6 +46,7 @@ >>>>>> * >>>>>> * HISTORY >>>>>> * 07/2001 Ported by Wayne Boyer >>>>>> + * 02/2010 Updated by shiwh@cn.fujitsu.com >>>>>> * >>>>>> * RESTRICTIONS >>>>>> * Test must be run as root. >>>>>> @@ -82,6 +86,7 @@ int main(int ac, char **av) >>>>>> { >>>>>> int lc; >>>>>> char *msg; >>>>>> + int exp_eno; >>>>>> >>>>>> char osname[OSNAMESZ]; >>>>>> int osnamelth, status; >>>>>> @@ -96,6 +101,13 @@ int main(int ac, char **av) >>>>>> >>>>>> setup(); >>>>>> >>>>>> + if ((tst_kvercmp(2, 6, 32)) <= 0){ >>>>>> + exp_eno = EPERM; >>>>>> + } else { >>>>>> + exp_eno = EACCES; >>>>>> + exp_enos[0] = EACCES; >>>>>> + } >>>>>> + >>>>>> TEST_EXP_ENOS(exp_enos); >>>>>> >>>>>> /* check looping state if -i option is given */ >>>>>> @@ -114,13 +126,10 @@ int main(int ac, char **av) >>>>>> } else { >>>>>> TEST_ERROR_LOG(TEST_ERRNO); >>>>>> >>>>>> - if (TEST_ERRNO != EPERM) { >>>>>> - tst_resm(TFAIL, >>>>>> - "Expected EPERM (%d), got %d: %s", >>>>>> - EPERM, TEST_ERRNO, >>>>>> - strerror(TEST_ERRNO)); >>>>>> + if (TEST_ERRNO != exp_eno) { >>>>>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error"); >>>>>> } else { >>>>>> - tst_resm(TPASS, "Got expected EPERM error"); >>>>>> + tst_resm(TPASS|TTERRNO, "Got expected error"); >>>>>> } >>>>>> } >>>>>> >>>>>> @@ -147,12 +156,10 @@ int main(int ac, char **av) >>>>>> } else { >>>>>> TEST_ERROR_LOG(TEST_ERRNO); >>>>>> >>>>>> - if (TEST_ERRNO != EPERM) { >>>>>> - tst_resm(TFAIL, "Expected EPERM, got " >>>>>> - "%d", TEST_ERRNO); >>>>>> + if (TEST_ERRNO != exp_eno) { >>>>> >>>>> Why can't this be exp_enos[0] ? >>>> >>>> Using exp_enos[0] is ok. pls check the latest patch in this mail. >>>> >>>>> >>>>>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error"); >>>>> >>>>> Typo. >>>>> >>>>>> } else { >>>>>> - tst_resm(TPASS, "Got expected EPERM " >>>>>> - "error"); >>>>>> + tst_resm(TPASS|TTERRNO, "Got expected error"); >>>>>> } >>>>>> } >>>>>> >>>>>> >>>>>> Thank you. >>>>>> - Shi Weihua >>>>> >>>>> It always helps to understand what's expected vs unexpected >>>>> without having to look at the source code. Could you please revise the >>>>> tst_resm format strings to be something like the following? >>>>> >>>>> tst_resm (TPASS | TERRNO, "Got expected error (errno = %d, ret_code = >>>>> %d", exp_errno_blah, exp_ret_code_blah); >>>>> >>>>> OR: >>>>> >>>>> tst_resm (TPASS | TERRNO, "Got unexpected error (expected errno = %d, >>>>> ret_code = %d - got errno = %d, ret_code = %d", exp_errno_blah, >>>>> exp_ret_code_blah, errno_blah, ret_code_blah); >>>> >>>> ret_code has not been defined in sysctl03.c, i think it's unnecessarily to >>>> import a new parameter. maybe, we can use your macro when it created. ;-) >>>> >>>> --- testcases/kernel/syscalls/sysctl/sysctl03.c.orig 2010-02-22 14:38:26.000000000 -0500 >>>> +++ testcases/kernel/syscalls/sysctl/sysctl03.c 2010-02-23 09:35:20.000000000 -0500 >>>> @@ -22,15 +22,18 @@ >>>> * sysctl03.c >>>> * >>>> * DESCRIPTION >>>> - * Testcase to check that sysctl(2) sets errno to EPERM correctly. >>>> + * Testcase to check that sysctl(2) sets errno to EPERM or EACCES >>>> + * correctly. But it will return EACCES on kernels that are 2.6.33-rc1 >>>> + * and higher. >>>> * >>>> * ALGORITHM >>>> * a. Call sysctl(2) as a root user, and attempt to write data >>>> * to the kernel_table[]. Since the table does not have write >>>> - * permissions even for the root, it should fail EPERM. >>>> + * permissions even for the root, it should fail EPERM or EACCES. >>>> * b. Call sysctl(2) as a non-root user, and attempt to write data >>>> * to the kernel_table[]. Since the table does not have write >>>> - * permission for the regular user, it should fail with EPERM. >>>> + * permission for the regular user, it should fail with EPERM >>>> + * or EACCES. >>>> * >>>> * USAGE: <for command-line> >>>> * sysctl03 [-c n] [-e] [-i n] [-I x] [-P x] [-t] >>>> @@ -43,6 +46,7 @@ >>>> * >>>> * HISTORY >>>> * 07/2001 Ported by Wayne Boyer >>>> + * 02/2010 Updated by shiwh@cn.fujitsu.com >>>> * >>>> * RESTRICTIONS >>>> * Test must be run as root. >>>> @@ -96,6 +100,12 @@ int main(int ac, char **av) >>>> >>>> setup(); >>>> >>>> + if ((tst_kvercmp(2, 6, 32)) <= 0){ >>>> + exp_enos[0] = EPERM; >>>> + } else { >>>> + exp_enos[0] = EACCES; >>>> + } >>>> + >>>> TEST_EXP_ENOS(exp_enos); >>>> >>>> /* check looping state if -i option is given */ >>>> @@ -114,13 +124,12 @@ int main(int ac, char **av) >>>> } else { >>>> TEST_ERROR_LOG(TEST_ERRNO); >>>> >>>> - if (TEST_ERRNO != EPERM) { >>>> - tst_resm(TFAIL, >>>> - "Expected EPERM (%d), got %d: %s", >>>> - EPERM, TEST_ERRNO, >>>> - strerror(TEST_ERRNO)); >>>> + if (TEST_ERRNO != exp_enos[0]) { >>>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error " >>>> + "(expected error = %d)", exp_enos[0]); >>>> } else { >>>> - tst_resm(TPASS, "Got expected EPERM error"); >>>> + tst_resm(TPASS|TTERRNO, "Got expected error " >>>> + "(errno = %d)", exp_enos[0]); >>>> } >>>> } >>>> >>>> @@ -147,12 +156,12 @@ int main(int ac, char **av) >>>> } else { >>>> TEST_ERROR_LOG(TEST_ERRNO); >>>> >>>> - if (TEST_ERRNO != EPERM) { >>>> - tst_resm(TFAIL, "Expected EPERM, got " >>>> - "%d", TEST_ERRNO); >>>> + if (TEST_ERRNO != exp_enos[0]) { >>>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error " >>>> + "(expected error = %d)", exp_enos[0]); >>>> } else { >>>> - tst_resm(TPASS, "Got expected EPERM " >>>> - "error"); >>>> + tst_resm(TPASS|TTERRNO, "Got expected error " >>>> + "(errno = %d)", exp_enos[0]); >>>> } >>>> } >>> >>> Ok, before I go and commit this, there are two things I need to know >>> (because trusty Google didn't turn up any results for this behavioral >>> change): >>> >>> 1. The change is legitimate. >>> 2. The documentation is up to date, or a bug has been filed for the >>> documentation change. >>> >>> If you can provide these two things, I'll commit the change. >> >> At this time of day, I can not find any documentation about EPERM->EACCES. >> But, i caught the kernel commit which caused ltp bug: >> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=26a7034b40ba80f82f64fa251a2cbf49f9971c6a >> Maybe it can help you to judge. > > Wow... that's a fair amount of code refactoring and additions to the syscall. > > Yes, all of the issues with opening a directory and reading/writing > now apply to sysctl(2), especially if someone attempts to read from a > write-only descriptor, or vice versa. No mismatches of file descriptor modes and how the descriptor is accessed can not occur. There is a file descriptor but the file descriptor is completely internal to binary_sysctl(), and it is opened with the mode of what we are trying to use. There are no user space controllable parts there. Looking through the old sysctl code it appears that it was a bug that kept it from returning EACCES. The code has had this beautiful snippet in it for ages: static int test_perm(int mode, int op) { if (!current->euid) mode >>= 6; else if (in_egroup_p(0)) mode >>= 3; if ((mode & op & 0007) == op) return 0; return -EACCES; } I admit that the manpage doesn't document EACCES but the manpage has always said don't use sysctl(2) so... > I hate to do this in such a reactive manner as this should have been > done up front, but the 1) documentation and 2) test need to be > updated. 1) is more key today because I'm not sure how much testing > the developer did before he committed to kernel.org, but without > updated documentation and requirements we can't write proper tests. You may see a slightly different error code from sysctl(2) on failure but otherwise sysctl(2) should be unchanged, and yes I did test it. Of course I was not being picky about which error code I got on failure. What exists today is simply a backwards compatibility wrapper of sysctl(2) built on top of /proc/sys. sysctl(2) was a practically unmaintained bit-rotting pile, that was never adequately maintained or tested. At this point nothing should change again until such time as the code is disabled/removed by default. Eric ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [LTP] [PATCH] sysctl03: sysctl returns EACCES after 2.6.33-rc1 2010-03-04 19:57 ` Eric W. Biederman @ 2010-03-05 7:20 ` Garrett Cooper 2010-03-05 7:50 ` Eric W. Biederman 0 siblings, 1 reply; 5+ messages in thread From: Garrett Cooper @ 2010-03-05 7:20 UTC (permalink / raw) To: Eric W. Biederman; +Cc: Shi Weihua, Rishikesh K Rajak, LTP, linux-kernel On Thu, Mar 4, 2010 at 11:57 AM, Eric W. Biederman <ebiederm@xmission.com> wrote: > Garrett Cooper <yanegomi@gmail.com> writes: > >> On Thu, Mar 4, 2010 at 12:38 AM, Shi Weihua <shiwh@cn.fujitsu.com> wrote: >>> at 2010-2-25 9:18, Garrett Cooper wrote: >>>> On Mon, Feb 22, 2010 at 5:48 PM, Shi Weihua <shiwh@cn.fujitsu.com> wrote: >>>>> at 2010-2-22 15:44, Garrett Cooper wrote: >>>>>> Ok.. one last thing. >>>>>> >>>>>> On Sun, Feb 21, 2010 at 11:15 PM, Shi Weihua <shiwh@cn.fujitsu.com> wrote: >>>>>>> at 2010-2-18 12:25, Rishikesh K Rajak wrote: >>>>>>>> On Wed, Feb 17, 2010 at 09:10:48AM -0800, Garrett Cooper wrote: >>>>>>>>> On Wed, Feb 17, 2010 at 12:01 AM, Rishikesh <risrajak@linux.vnet.ibm.com> wrote: >>>>>>>>>> Hi Shi, >>>>>>>>>> >>>>>>>>>> Thanks for your patch, still i am finding time to look into your patch. >>>>>>>>>> Will reply you soon. >>>>>>>>>> >>>>>>>>>> http://marc.info/?l=ltp-list&m=126502355614857&w=2 >>>>>>>>> >>>>>>>>> I looked at the patch finally. >>>>>>>> >>>>>>>> Thanks garret. >>>>>>>>> >>>>>>>>> Please use TTERRNO instead of strerror(...) for the reported value. >>>>>>>>> There's no reason why you should use strerror(...) there as that's >>>>>>>>> already done with tst_res(3). >>>>>>>> >>>>>>>> Shi, can you please incorporate changes which garret has suggested and >>>>>>>> resend the patch again to ltp-list@ . >>>>>>> >>>>>>> Ok, i recreated the patch based on garret's suggestion. >>>>>>> >>>>>>> Signed-off-by: Shi Weihua <shiwh@cn.fujitsu.com> >>>>>>> --- >>>>>>> --- testcases/kernel/syscalls/sysctl/sysctl03.c.orig 2010-02-22 14:38:26.000000000 -0500 >>>>>>> +++ testcases/kernel/syscalls/sysctl/sysctl03.c 2010-02-22 15:08:03.000000000 -0500 >>>>>>> @@ -22,15 +22,18 @@ >>>>>>> * sysctl03.c >>>>>>> * >>>>>>> * DESCRIPTION >>>>>>> - * Testcase to check that sysctl(2) sets errno to EPERM correctly. >>>>>>> + * Testcase to check that sysctl(2) sets errno to EPERM or EACCES >>>>>>> + * correctly. But it will return EACCES on kernels that are 2.6.33-rc1 >>>>>>> + * and higher. >>>>>>> * >>>>>>> * ALGORITHM >>>>>>> * a. Call sysctl(2) as a root user, and attempt to write data >>>>>>> * to the kernel_table[]. Since the table does not have write >>>>>>> - * permissions even for the root, it should fail EPERM. >>>>>>> + * permissions even for the root, it should fail EPERM or EACCES. >>>>>>> * b. Call sysctl(2) as a non-root user, and attempt to write data >>>>>>> * to the kernel_table[]. Since the table does not have write >>>>>>> - * permission for the regular user, it should fail with EPERM. >>>>>>> + * permission for the regular user, it should fail with EPERM >>>>>>> + * or EACCES. >>>>>>> * >>>>>>> * USAGE: <for command-line> >>>>>>> * sysctl03 [-c n] [-e] [-i n] [-I x] [-P x] [-t] >>>>>>> @@ -43,6 +46,7 @@ >>>>>>> * >>>>>>> * HISTORY >>>>>>> * 07/2001 Ported by Wayne Boyer >>>>>>> + * 02/2010 Updated by shiwh@cn.fujitsu.com >>>>>>> * >>>>>>> * RESTRICTIONS >>>>>>> * Test must be run as root. >>>>>>> @@ -82,6 +86,7 @@ int main(int ac, char **av) >>>>>>> { >>>>>>> int lc; >>>>>>> char *msg; >>>>>>> + int exp_eno; >>>>>>> >>>>>>> char osname[OSNAMESZ]; >>>>>>> int osnamelth, status; >>>>>>> @@ -96,6 +101,13 @@ int main(int ac, char **av) >>>>>>> >>>>>>> setup(); >>>>>>> >>>>>>> + if ((tst_kvercmp(2, 6, 32)) <= 0){ >>>>>>> + exp_eno = EPERM; >>>>>>> + } else { >>>>>>> + exp_eno = EACCES; >>>>>>> + exp_enos[0] = EACCES; >>>>>>> + } >>>>>>> + >>>>>>> TEST_EXP_ENOS(exp_enos); >>>>>>> >>>>>>> /* check looping state if -i option is given */ >>>>>>> @@ -114,13 +126,10 @@ int main(int ac, char **av) >>>>>>> } else { >>>>>>> TEST_ERROR_LOG(TEST_ERRNO); >>>>>>> >>>>>>> - if (TEST_ERRNO != EPERM) { >>>>>>> - tst_resm(TFAIL, >>>>>>> - "Expected EPERM (%d), got %d: %s", >>>>>>> - EPERM, TEST_ERRNO, >>>>>>> - strerror(TEST_ERRNO)); >>>>>>> + if (TEST_ERRNO != exp_eno) { >>>>>>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error"); >>>>>>> } else { >>>>>>> - tst_resm(TPASS, "Got expected EPERM error"); >>>>>>> + tst_resm(TPASS|TTERRNO, "Got expected error"); >>>>>>> } >>>>>>> } >>>>>>> >>>>>>> @@ -147,12 +156,10 @@ int main(int ac, char **av) >>>>>>> } else { >>>>>>> TEST_ERROR_LOG(TEST_ERRNO); >>>>>>> >>>>>>> - if (TEST_ERRNO != EPERM) { >>>>>>> - tst_resm(TFAIL, "Expected EPERM, got " >>>>>>> - "%d", TEST_ERRNO); >>>>>>> + if (TEST_ERRNO != exp_eno) { >>>>>> >>>>>> Why can't this be exp_enos[0] ? >>>>> >>>>> Using exp_enos[0] is ok. pls check the latest patch in this mail. >>>>> >>>>>> >>>>>>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error"); >>>>>> >>>>>> Typo. >>>>>> >>>>>>> } else { >>>>>>> - tst_resm(TPASS, "Got expected EPERM " >>>>>>> - "error"); >>>>>>> + tst_resm(TPASS|TTERRNO, "Got expected error"); >>>>>>> } >>>>>>> } >>>>>>> >>>>>>> >>>>>>> Thank you. >>>>>>> - Shi Weihua >>>>>> >>>>>> It always helps to understand what's expected vs unexpected >>>>>> without having to look at the source code. Could you please revise the >>>>>> tst_resm format strings to be something like the following? >>>>>> >>>>>> tst_resm (TPASS | TERRNO, "Got expected error (errno = %d, ret_code = >>>>>> %d", exp_errno_blah, exp_ret_code_blah); >>>>>> >>>>>> OR: >>>>>> >>>>>> tst_resm (TPASS | TERRNO, "Got unexpected error (expected errno = %d, >>>>>> ret_code = %d - got errno = %d, ret_code = %d", exp_errno_blah, >>>>>> exp_ret_code_blah, errno_blah, ret_code_blah); >>>>> >>>>> ret_code has not been defined in sysctl03.c, i think it's unnecessarily to >>>>> import a new parameter. maybe, we can use your macro when it created. ;-) >>>>> >>>>> --- testcases/kernel/syscalls/sysctl/sysctl03.c.orig 2010-02-22 14:38:26.000000000 -0500 >>>>> +++ testcases/kernel/syscalls/sysctl/sysctl03.c 2010-02-23 09:35:20.000000000 -0500 >>>>> @@ -22,15 +22,18 @@ >>>>> * sysctl03.c >>>>> * >>>>> * DESCRIPTION >>>>> - * Testcase to check that sysctl(2) sets errno to EPERM correctly. >>>>> + * Testcase to check that sysctl(2) sets errno to EPERM or EACCES >>>>> + * correctly. But it will return EACCES on kernels that are 2.6.33-rc1 >>>>> + * and higher. >>>>> * >>>>> * ALGORITHM >>>>> * a. Call sysctl(2) as a root user, and attempt to write data >>>>> * to the kernel_table[]. Since the table does not have write >>>>> - * permissions even for the root, it should fail EPERM. >>>>> + * permissions even for the root, it should fail EPERM or EACCES. >>>>> * b. Call sysctl(2) as a non-root user, and attempt to write data >>>>> * to the kernel_table[]. Since the table does not have write >>>>> - * permission for the regular user, it should fail with EPERM. >>>>> + * permission for the regular user, it should fail with EPERM >>>>> + * or EACCES. >>>>> * >>>>> * USAGE: <for command-line> >>>>> * sysctl03 [-c n] [-e] [-i n] [-I x] [-P x] [-t] >>>>> @@ -43,6 +46,7 @@ >>>>> * >>>>> * HISTORY >>>>> * 07/2001 Ported by Wayne Boyer >>>>> + * 02/2010 Updated by shiwh@cn.fujitsu.com >>>>> * >>>>> * RESTRICTIONS >>>>> * Test must be run as root. >>>>> @@ -96,6 +100,12 @@ int main(int ac, char **av) >>>>> >>>>> setup(); >>>>> >>>>> + if ((tst_kvercmp(2, 6, 32)) <= 0){ >>>>> + exp_enos[0] = EPERM; >>>>> + } else { >>>>> + exp_enos[0] = EACCES; >>>>> + } >>>>> + >>>>> TEST_EXP_ENOS(exp_enos); >>>>> >>>>> /* check looping state if -i option is given */ >>>>> @@ -114,13 +124,12 @@ int main(int ac, char **av) >>>>> } else { >>>>> TEST_ERROR_LOG(TEST_ERRNO); >>>>> >>>>> - if (TEST_ERRNO != EPERM) { >>>>> - tst_resm(TFAIL, >>>>> - "Expected EPERM (%d), got %d: %s", >>>>> - EPERM, TEST_ERRNO, >>>>> - strerror(TEST_ERRNO)); >>>>> + if (TEST_ERRNO != exp_enos[0]) { >>>>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error " >>>>> + "(expected error = %d)", exp_enos[0]); >>>>> } else { >>>>> - tst_resm(TPASS, "Got expected EPERM error"); >>>>> + tst_resm(TPASS|TTERRNO, "Got expected error " >>>>> + "(errno = %d)", exp_enos[0]); >>>>> } >>>>> } >>>>> >>>>> @@ -147,12 +156,12 @@ int main(int ac, char **av) >>>>> } else { >>>>> TEST_ERROR_LOG(TEST_ERRNO); >>>>> >>>>> - if (TEST_ERRNO != EPERM) { >>>>> - tst_resm(TFAIL, "Expected EPERM, got " >>>>> - "%d", TEST_ERRNO); >>>>> + if (TEST_ERRNO != exp_enos[0]) { >>>>> + tst_resm(TFAIL|TTERRNO, "Got unxpected error " >>>>> + "(expected error = %d)", exp_enos[0]); >>>>> } else { >>>>> - tst_resm(TPASS, "Got expected EPERM " >>>>> - "error"); >>>>> + tst_resm(TPASS|TTERRNO, "Got expected error " >>>>> + "(errno = %d)", exp_enos[0]); >>>>> } >>>>> } >>>> >>>> Ok, before I go and commit this, there are two things I need to know >>>> (because trusty Google didn't turn up any results for this behavioral >>>> change): >>>> >>>> 1. The change is legitimate. >>>> 2. The documentation is up to date, or a bug has been filed for the >>>> documentation change. >>>> >>>> If you can provide these two things, I'll commit the change. >>> >>> At this time of day, I can not find any documentation about EPERM->EACCES. >>> But, i caught the kernel commit which caused ltp bug: >>> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=26a7034b40ba80f82f64fa251a2cbf49f9971c6a >>> Maybe it can help you to judge. >> >> Wow... that's a fair amount of code refactoring and additions to the syscall. >> >> Yes, all of the issues with opening a directory and reading/writing >> now apply to sysctl(2), especially if someone attempts to read from a >> write-only descriptor, or vice versa. > > No mismatches of file descriptor modes and how the descriptor is > accessed can not occur. There is a file descriptor but the file > descriptor is completely internal to binary_sysctl(), and it is opened > with the mode of what we are trying to use. There are no user space > controllable parts there. > > Looking through the old sysctl code it appears that it was a bug that > kept it from returning EACCES. The code has had this beautiful snippet > in it for ages: > > static int test_perm(int mode, int op) > { > if (!current->euid) > mode >>= 6; > else if (in_egroup_p(0)) > mode >>= 3; > if ((mode & op & 0007) == op) > return 0; > return -EACCES; > } Wow. Took a second for me to stare and it and see what you mean, but yeah -- that is pretty dang awesome that it was always hardwired to return 0. > I admit that the manpage doesn't document EACCES but the manpage > has always said don't use sysctl(2) so... Well, if someone bumbles across this later, it will be a confusing issue to work through. It's better to be documented instead of undocumented. I'll file the bug upstream to document this, but it would be nice to determine if there are any more immediate gaps which need to be addressed in the changes. >> I hate to do this in such a reactive manner as this should have been >> done up front, but the 1) documentation and 2) test need to be >> updated. 1) is more key today because I'm not sure how much testing >> the developer did before he committed to kernel.org, but without >> updated documentation and requirements we can't write proper tests. > > You may see a slightly different error code from sysctl(2) on failure > but otherwise sysctl(2) should be unchanged, and yes I did test it. > Of course I was not being picky about which error code I got on failure. Hmmm.. ok. We just get 20 questions when something fails and it's not documented why it should fail in a particular manner :). > What exists today is simply a backwards compatibility wrapper of > sysctl(2) built on top of /proc/sys. sysctl(2) was a practically > unmaintained bit-rotting pile, that was never adequately maintained or > tested. Yeah, you're probably right (especially because Linux tends not to focus on sysctl(3) like the BSDs do). > At this point nothing should change again until such time as the code > is disabled/removed by default. Hmmm... ok. I assume that sysctl(2) is going completely out the window in the future, in favor of what (just out of curiosity)? 100% sysfs only tunables maybe? Thanks, -Garrett ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [LTP] [PATCH] sysctl03: sysctl returns EACCES after 2.6.33-rc1 2010-03-05 7:20 ` Garrett Cooper @ 2010-03-05 7:50 ` Eric W. Biederman 0 siblings, 0 replies; 5+ messages in thread From: Eric W. Biederman @ 2010-03-05 7:50 UTC (permalink / raw) To: Garrett Cooper; +Cc: Shi Weihua, Rishikesh K Rajak, LTP, linux-kernel Garrett Cooper <yanegomi@gmail.com> writes: > On Thu, Mar 4, 2010 at 11:57 AM, Eric W. Biederman > <ebiederm@xmission.com> wrote: >> Garrett Cooper <yanegomi@gmail.com> writes: >>> >>> Wow... that's a fair amount of code refactoring and additions to the syscall. >>> >>> Yes, all of the issues with opening a directory and reading/writing >>> now apply to sysctl(2), especially if someone attempts to read from a >>> write-only descriptor, or vice versa. >> >> No mismatches of file descriptor modes and how the descriptor is >> accessed can not occur. There is a file descriptor but the file >> descriptor is completely internal to binary_sysctl(), and it is opened >> with the mode of what we are trying to use. There are no user space >> controllable parts there. >> >> Looking through the old sysctl code it appears that it was a bug that >> kept it from returning EACCES. The code has had this beautiful snippet >> in it for ages: >> >> static int test_perm(int mode, int op) >> { >> if (!current->euid) >> mode >>= 6; >> else if (in_egroup_p(0)) >> mode >>= 3; >> if ((mode & op & 0007) == op) >> return 0; >> return -EACCES; >> } > > Wow. Took a second for me to stare and it and see what you mean, > but yeah -- that is pretty dang awesome that it was always hardwired > to return 0. Sorry that wasn't clear without context. What used to happen where all of the callers of that function did: if (test_perm(...)) return -EPERM; Instead of the much more conventional: err = test_perm() if (err) return err; >> I admit that the manpage doesn't document EACCES but the manpage >> has always said don't use sysctl(2) so... > > Well, if someone bumbles across this later, it will be a confusing > issue to work through. It's better to be documented instead of > undocumented. I'll file the bug upstream to document this, but it > would be nice to determine if there are any more immediate gaps which > need to be addressed in the changes. I think the linux test project may be nearly the only caller of sysctl(2) at this point. At least until recently there was one caller in arm glibc. But finding any program that uses sysctl(2) is nearly impossible. >> You may see a slightly different error code from sysctl(2) on failure >> but otherwise sysctl(2) should be unchanged, and yes I did test it. >> Of course I was not being picky about which error code I got on failure. > > Hmmm.. ok. We just get 20 questions when something fails and it's > not documented why it should fail in a particular manner :). >> What exists today is simply a backwards compatibility wrapper of >> sysctl(2) built on top of /proc/sys. sysctl(2) was a practically >> unmaintained bit-rotting pile, that was never adequately maintained or >> tested. > > Yeah, you're probably right (especially because Linux tends not to > focus on sysctl(3) like the BSDs do). > >> At this point nothing should change again until such time as the code >> is disabled/removed by default. > > Hmmm... ok. I assume that sysctl(2) is going completely out the > window in the future, in favor of what (just out of curiosity)? 100% > sysfs only tunables maybe? /proc/sys is going to stay. Which is what people have actually used. Even /sbin/sysctl has always used /proc/sys. Nothing anyone actually uses is going to go away. Just the practically dead code that is the syscall is slowly going away. Since I have written the emulation layer the need for it to disappear is less immediate than it once was, but I will strongly discourage anyone from using it. Eric ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2010-03-05 7:50 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <4B7BA24F.2010705@linux.vnet.ibm.com>
[not found] ` <364299f41002170910i336abf6eh72acbcbec9b72e7b@mail.gmail.com>
[not found] ` <20100218042532.GC13013@rishikesh.in.ibm.com>
[not found] ` <4B822F2E.9030609@cn.fujitsu.com>
[not found] ` <364299f41002212344v4873843ej986f1b39ec3494df@mail.gmail.com>
[not found] ` <4B8333ED.5080709@cn.fujitsu.com>
[not found] ` <364299f41002241718g4be216d1pbec918821b7027b0@mail.gmail.com>
[not found] ` <4B8F716E.5070207@cn.fujitsu.com>
2010-03-04 18:35 ` [LTP] [PATCH] sysctl03: sysctl returns EACCES after 2.6.33-rc1 Garrett Cooper
2010-03-04 18:37 ` Garrett Cooper
2010-03-04 19:57 ` Eric W. Biederman
2010-03-05 7:20 ` Garrett Cooper
2010-03-05 7:50 ` Eric W. Biederman
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox