| Message ID | 20240912103151.1520254-1-usama.anjum@collabora.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] kselftests: mm: Fix wrong __NR_userfaultfd value | expand |
On 9/12/24 8:44 PM, Shuah Khan wrote: > On 9/12/24 04:31, Muhammad Usama Anjum wrote: >> The value of __NR_userfaultfd was changed to 282 when >> asm-generic/unistd.h was included. It makes the test to fail every time >> as the correct number of this syscall on x86_64 is 323. Fix the header >> to asm/unistd.h. >> > > "please elaborate every time" - I just built on my x86_64 and built > just fine. The build isn't broken. > I am not saying this isn't a problem, it is good to > understand why and how it is failing before making the change. I mean to say that the test is failing at run time because the correct userfaultfd syscall isn't being found with __NR_userfaultfd = 282. _NR_userfaultfd's value depends on the header. When asm-generic/unistd.h is included, its value (282) is wrong. I've tested on x86_64. The fix is simple. Add the correct header which has _NR_userfaultfd = 323. > >> Fixes: a5c6bc590094 ("selftests/mm: remove local __NR_* definitions") >> Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> >> --- >> tools/testing/selftests/mm/pagemap_ioctl.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/tools/testing/selftests/mm/pagemap_ioctl.c >> b/tools/testing/selftests/mm/pagemap_ioctl.c >> index fc90af2a97b80..bcc73b4e805c6 100644 >> --- a/tools/testing/selftests/mm/pagemap_ioctl.c >> +++ b/tools/testing/selftests/mm/pagemap_ioctl.c >> @@ -15,7 +15,7 @@ >> #include <sys/ioctl.h> >> #include <sys/stat.h> >> #include <math.h> >> -#include <asm-generic/unistd.h> >> +#include <asm/unistd.h> >> #include <pthread.h> >> #include <sys/resource.h> >> #include <assert.h> > > Also please generate a series with these two patches with cover-letter. > > thanks, > -- Shuah
On 9/16/24 00:32, Muhammad Usama Anjum wrote: > On 9/12/24 8:44 PM, Shuah Khan wrote: >> On 9/12/24 04:31, Muhammad Usama Anjum wrote: >>> The value of __NR_userfaultfd was changed to 282 when >>> asm-generic/unistd.h was included. It makes the test to fail every time >>> as the correct number of this syscall on x86_64 is 323. Fix the header >>> to asm/unistd.h. >>> >> >> "please elaborate every time" - I just built on my x86_64 and built >> just fine. > The build isn't broken. > >> I am not saying this isn't a problem, it is good to >> understand why and how it is failing before making the change. > I mean to say that the test is failing at run time because the correct > userfaultfd syscall isn't being found with __NR_userfaultfd = 282. > _NR_userfaultfd's value depends on the header. When asm-generic/unistd.h > is included, its value (282) is wrong. I've tested on x86_64. > Okay - how do you know this is wrong? can you provide more details. git grep _NR_userfaultfd include/uapi/asm-generic/unistd.h:#define __NR_userfaultfd 282 include/uapi/asm-generic/unistd.h:__SYSCALL(__NR_userfaultfd, sys_userfaultfd) tools/include/uapi/asm-generic/unistd.h:#define __NR_userfaultfd 282 > The fix is simple. Add the correct header which has _NR_userfaultfd = 323. I need more details on this number. thanks, -- Shuah
On 9/17/24 6:56 AM, Shuah Khan wrote: > On 9/16/24 00:32, Muhammad Usama Anjum wrote: >> On 9/12/24 8:44 PM, Shuah Khan wrote: >>> On 9/12/24 04:31, Muhammad Usama Anjum wrote: >>>> The value of __NR_userfaultfd was changed to 282 when >>>> asm-generic/unistd.h was included. It makes the test to fail every time >>>> as the correct number of this syscall on x86_64 is 323. Fix the header >>>> to asm/unistd.h. >>>> >>> >>> "please elaborate every time" - I just built on my x86_64 and built >>> just fine. >> The build isn't broken. >> >>> I am not saying this isn't a problem, it is good to >>> understand why and how it is failing before making the change. >> I mean to say that the test is failing at run time because the correct >> userfaultfd syscall isn't being found with __NR_userfaultfd = 282. >> _NR_userfaultfd's value depends on the header. When asm-generic/unistd.h >> is included, its value (282) is wrong. I've tested on x86_64. >> > > Okay - how do you know this is wrong? can you provide more details. > > git grep _NR_userfaultfd > include/uapi/asm-generic/unistd.h:#define __NR_userfaultfd 282 > include/uapi/asm-generic/unistd.h:__SYSCALL(__NR_userfaultfd, > sys_userfaultfd) > tools/include/uapi/asm-generic/unistd.h:#define __NR_userfaultfd 282 > >> The fix is simple. Add the correct header which has _NR_userfaultfd = >> 323. grep -rnIF "#define __NR_userfaultfd" tools/include/uapi/asm-generic/unistd.h:681:#define __NR_userfaultfd 282 arch/x86/include/generated/uapi/asm/unistd_32.h:374:#define __NR_userfaultfd 374 arch/x86/include/generated/uapi/asm/unistd_64.h:327:#define __NR_userfaultfd 323 arch/x86/include/generated/uapi/asm/unistd_x32.h:282:#define __NR_userfaultfd (__X32_SYSCALL_BIT + 323) arch/arm/include/generated/uapi/asm/unistd-eabi.h:347:#define __NR_userfaultfd (__NR_SYSCALL_BASE + 388) arch/arm/include/generated/uapi/asm/unistd-oabi.h:359:#define __NR_userfaultfd (__NR_SYSCALL_BASE + 388) include/uapi/asm-generic/unistd.h:681:#define __NR_userfaultfd 282 The number is dependent on the architecture. The above data shows that: x86 374 x86_64 323 I'm unable to find the history of why it is set to 282 in unistd.h and when this problem happened. > > I need more details on this number. > > thanks, > -- Shuah
On 9/18/24 10:46 AM, Muhammad Usama Anjum wrote: > On 9/17/24 6:56 AM, Shuah Khan wrote: >> On 9/16/24 00:32, Muhammad Usama Anjum wrote: >>> On 9/12/24 8:44 PM, Shuah Khan wrote: >>>> On 9/12/24 04:31, Muhammad Usama Anjum wrote: >>>>> The value of __NR_userfaultfd was changed to 282 when >>>>> asm-generic/unistd.h was included. It makes the test to fail every time >>>>> as the correct number of this syscall on x86_64 is 323. Fix the header >>>>> to asm/unistd.h. >>>>> >>>> >>>> "please elaborate every time" - I just built on my x86_64 and built >>>> just fine. >>> The build isn't broken. >>> >>>> I am not saying this isn't a problem, it is good to >>>> understand why and how it is failing before making the change. >>> I mean to say that the test is failing at run time because the correct >>> userfaultfd syscall isn't being found with __NR_userfaultfd = 282. >>> _NR_userfaultfd's value depends on the header. When asm-generic/unistd.h >>> is included, its value (282) is wrong. I've tested on x86_64. >>> >> >> Okay - how do you know this is wrong? can you provide more details. >> >> git grep _NR_userfaultfd >> include/uapi/asm-generic/unistd.h:#define __NR_userfaultfd 282 >> include/uapi/asm-generic/unistd.h:__SYSCALL(__NR_userfaultfd, >> sys_userfaultfd) >> tools/include/uapi/asm-generic/unistd.h:#define __NR_userfaultfd 282 >> >>> The fix is simple. Add the correct header which has _NR_userfaultfd = >>> 323. > > grep -rnIF "#define __NR_userfaultfd" > tools/include/uapi/asm-generic/unistd.h:681:#define __NR_userfaultfd 282 > arch/x86/include/generated/uapi/asm/unistd_32.h:374:#define > __NR_userfaultfd 374 > arch/x86/include/generated/uapi/asm/unistd_64.h:327:#define > __NR_userfaultfd 323 > arch/x86/include/generated/uapi/asm/unistd_x32.h:282:#define > __NR_userfaultfd (__X32_SYSCALL_BIT + 323) > arch/arm/include/generated/uapi/asm/unistd-eabi.h:347:#define > __NR_userfaultfd (__NR_SYSCALL_BASE + 388) > arch/arm/include/generated/uapi/asm/unistd-oabi.h:359:#define > __NR_userfaultfd (__NR_SYSCALL_BASE + 388) > include/uapi/asm-generic/unistd.h:681:#define __NR_userfaultfd 282 > > The number is dependent on the architecture. The above data shows that: > x86 374 > x86_64 323 > > I'm unable to find the history of why it is set to 282 in unistd.h and > when this problem happened. Does anybody has understanding of this? > >> >> I need more details on this number. >> >> thanks, >> -- Shuah >
On 9/17/24 23:46, Muhammad Usama Anjum wrote: > On 9/17/24 6:56 AM, Shuah Khan wrote: >> On 9/16/24 00:32, Muhammad Usama Anjum wrote: >>> On 9/12/24 8:44 PM, Shuah Khan wrote: >>>> On 9/12/24 04:31, Muhammad Usama Anjum wrote: >>>>> The value of __NR_userfaultfd was changed to 282 when >>>>> asm-generic/unistd.h was included. It makes the test to fail every time >>>>> as the correct number of this syscall on x86_64 is 323. Fix the header >>>>> to asm/unistd.h. >>>>> >>>> >>>> "please elaborate every time" - I just built on my x86_64 and built >>>> just fine. >>> The build isn't broken. >>> >>>> I am not saying this isn't a problem, it is good to >>>> understand why and how it is failing before making the change. >>> I mean to say that the test is failing at run time because the correct >>> userfaultfd syscall isn't being found with __NR_userfaultfd = 282. >>> _NR_userfaultfd's value depends on the header. When asm-generic/unistd.h >>> is included, its value (282) is wrong. I've tested on x86_64. >>> >> >> Okay - how do you know this is wrong? can you provide more details. >> >> git grep _NR_userfaultfd >> include/uapi/asm-generic/unistd.h:#define __NR_userfaultfd 282 >> include/uapi/asm-generic/unistd.h:__SYSCALL(__NR_userfaultfd, >> sys_userfaultfd) >> tools/include/uapi/asm-generic/unistd.h:#define __NR_userfaultfd 282 >> >>> The fix is simple. Add the correct header which has _NR_userfaultfd = >>> 323. > > grep -rnIF "#define __NR_userfaultfd" > tools/include/uapi/asm-generic/unistd.h:681:#define __NR_userfaultfd 282 > arch/x86/include/generated/uapi/asm/unistd_32.h:374:#define > __NR_userfaultfd 374 > arch/x86/include/generated/uapi/asm/unistd_64.h:327:#define > __NR_userfaultfd 323 > arch/x86/include/generated/uapi/asm/unistd_x32.h:282:#define > __NR_userfaultfd (__X32_SYSCALL_BIT + 323) > arch/arm/include/generated/uapi/asm/unistd-eabi.h:347:#define > __NR_userfaultfd (__NR_SYSCALL_BASE + 388) > arch/arm/include/generated/uapi/asm/unistd-oabi.h:359:#define > __NR_userfaultfd (__NR_SYSCALL_BASE + 388) > include/uapi/asm-generic/unistd.h:681:#define __NR_userfaultfd 282 > > The number is dependent on the architecture. The above data shows that: > x86 374 > x86_64 323 Correct and the generated header files do the right thing and it is good to include them as this patch does. This is a good find and fix. I wish you explained this in your changelog. Please add more details when you send v2. There could be other issues lurking based on what I found. The other two files are the problem where they hard code it to 282 without taking the __NR_SYSCALL_BASE for the arch into consideration: tools/include/uapi/asm-generic/unistd.h:681:#define __NR_userfaultfd 282 include/uapi/asm-generic/unistd.h:681:#define __NR_userfaultfd 282 > > I'm unable to find the history of why it is set to 282 in unistd.h and > when this problem happened. According to git history it is added in the following commit to include/uapi/asm-generic/unistd.h: 09f7298100ea9767324298ab0c7979f6d7463183 Subject: [PATCH] userfaultfd: register uapi generic syscall (aarch64) and it is added in the following commit to tools/include/uapi/asm-generic/unistd.h 34b009cfde2b8ce20a69c7bfd6bad4ce0e7cd970 Subject: [PATCH] tools include: Grab copies of arm64 dependent unistd.h files I think, the above defines from include/uapi/asm-generic/unistd.h and tools/include/uapi/asm-generic/unistd.h should be removed. Maybe others familiar with userfaultfd can determine the best course of action. We might have other NR_ defines in these two files that are causing problems for tests and tools that we haven't uncovered yet. thanks, -- Shuah
diff --git a/tools/testing/selftests/mm/pagemap_ioctl.c b/tools/testing/selftests/mm/pagemap_ioctl.c index fc90af2a97b80..bcc73b4e805c6 100644 --- a/tools/testing/selftests/mm/pagemap_ioctl.c +++ b/tools/testing/selftests/mm/pagemap_ioctl.c @@ -15,7 +15,7 @@ #include <sys/ioctl.h> #include <sys/stat.h> #include <math.h> -#include <asm-generic/unistd.h> +#include <asm/unistd.h> #include <pthread.h> #include <sys/resource.h> #include <assert.h>
The value of __NR_userfaultfd was changed to 282 when asm-generic/unistd.h was included. It makes the test to fail every time as the correct number of this syscall on x86_64 is 323. Fix the header to asm/unistd.h. Fixes: a5c6bc590094 ("selftests/mm: remove local __NR_* definitions") Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> --- tools/testing/selftests/mm/pagemap_ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)