| Message ID | 20250115233747.GA28541@strace.io |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] selftests/ptrace/get_syscall_info: fix for MIPS n32 | expand |
Could somebody pick up this patch, please? Nothing has changed since v2, so I have nothing new to add. v2: https://lore.kernel.org/all/20250115233747.GA28541@strace.io/ On Thu, Jan 16, 2025 at 01:37:47AM +0200, Dmitry V. Levin wrote: > MIPS n32 is one of two ILP32 architectures supported by the kernel > that have 64-bit syscall arguments (another one is x32). > > When this test passed 32-bit arguments to syscall(), they were > sign-extended in libc, PTRACE_GET_SYSCALL_INFO reported these > sign-extended 64-bit values, and the test complained about the mismatch. > > Fix this by passing arguments of the appropriate type to syscall(), > which is "unsigned long long" on MIPS n32, and __kernel_ulong_t on other > architectures. > > As a side effect, this also extends the test on all 64-bit architectures > by choosing constants that don't fit into 32-bit integers. > > Signed-off-by: Dmitry V. Levin <ldv@strace.io> > --- > > v2: Fixed MIPS #ifdef. > > .../selftests/ptrace/get_syscall_info.c | 53 +++++++++++-------- > 1 file changed, 32 insertions(+), 21 deletions(-) > > diff --git a/tools/testing/selftests/ptrace/get_syscall_info.c b/tools/testing/selftests/ptrace/get_syscall_info.c > index 5bcd1c7b5be6..2970f72d66d3 100644 > --- a/tools/testing/selftests/ptrace/get_syscall_info.c > +++ b/tools/testing/selftests/ptrace/get_syscall_info.c > @@ -11,8 +11,19 @@ > #include <err.h> > #include <signal.h> > #include <asm/unistd.h> > +#include <linux/types.h> > #include "linux/ptrace.h" > > +#if defined(_MIPS_SIM) && _MIPS_SIM == _MIPS_SIM_NABI32 > +/* > + * MIPS N32 is the only architecture where __kernel_ulong_t > + * does not match the bitness of syscall arguments. > + */ > +typedef unsigned long long kernel_ulong_t; > +#else > +typedef __kernel_ulong_t kernel_ulong_t; > +#endif > + > static int > kill_tracee(pid_t pid) > { > @@ -42,37 +53,37 @@ sys_ptrace(int request, pid_t pid, unsigned long addr, unsigned long data) > > TEST(get_syscall_info) > { > - static const unsigned long args[][7] = { > + const kernel_ulong_t args[][7] = { > /* a sequence of architecture-agnostic syscalls */ > { > __NR_chdir, > - (unsigned long) "", > - 0xbad1fed1, > - 0xbad2fed2, > - 0xbad3fed3, > - 0xbad4fed4, > - 0xbad5fed5 > + (uintptr_t) "", > + (kernel_ulong_t) 0xdad1bef1bad1fed1ULL, > + (kernel_ulong_t) 0xdad2bef2bad2fed2ULL, > + (kernel_ulong_t) 0xdad3bef3bad3fed3ULL, > + (kernel_ulong_t) 0xdad4bef4bad4fed4ULL, > + (kernel_ulong_t) 0xdad5bef5bad5fed5ULL > }, > { > __NR_gettid, > - 0xcaf0bea0, > - 0xcaf1bea1, > - 0xcaf2bea2, > - 0xcaf3bea3, > - 0xcaf4bea4, > - 0xcaf5bea5 > + (kernel_ulong_t) 0xdad0bef0caf0bea0ULL, > + (kernel_ulong_t) 0xdad1bef1caf1bea1ULL, > + (kernel_ulong_t) 0xdad2bef2caf2bea2ULL, > + (kernel_ulong_t) 0xdad3bef3caf3bea3ULL, > + (kernel_ulong_t) 0xdad4bef4caf4bea4ULL, > + (kernel_ulong_t) 0xdad5bef5caf5bea5ULL > }, > { > __NR_exit_group, > 0, > - 0xfac1c0d1, > - 0xfac2c0d2, > - 0xfac3c0d3, > - 0xfac4c0d4, > - 0xfac5c0d5 > + (kernel_ulong_t) 0xdad1bef1fac1c0d1ULL, > + (kernel_ulong_t) 0xdad2bef2fac2c0d2ULL, > + (kernel_ulong_t) 0xdad3bef3fac3c0d3ULL, > + (kernel_ulong_t) 0xdad4bef4fac4c0d4ULL, > + (kernel_ulong_t) 0xdad5bef5fac5c0d5ULL > } > }; > - const unsigned long *exp_args; > + const kernel_ulong_t *exp_args; > > pid_t pid = fork(); > > @@ -154,7 +165,7 @@ TEST(get_syscall_info) > } > ASSERT_LT(0, (rc = sys_ptrace(PTRACE_GET_SYSCALL_INFO, > pid, size, > - (unsigned long) &info))) { > + (uintptr_t) &info))) { > LOG_KILL_TRACEE("PTRACE_GET_SYSCALL_INFO: %m"); > } > ASSERT_EQ(expected_none_size, rc) { > @@ -177,7 +188,7 @@ TEST(get_syscall_info) > case SIGTRAP | 0x80: > ASSERT_LT(0, (rc = sys_ptrace(PTRACE_GET_SYSCALL_INFO, > pid, size, > - (unsigned long) &info))) { > + (uintptr_t) &info))) { > LOG_KILL_TRACEE("PTRACE_GET_SYSCALL_INFO: %m"); > } > switch (ptrace_stop) { > -- > ldv
On 1/15/25 16:37, Dmitry V. Levin wrote: > MIPS n32 is one of two ILP32 architectures supported by the kernel > that have 64-bit syscall arguments (another one is x32). > > When this test passed 32-bit arguments to syscall(), they were > sign-extended in libc, PTRACE_GET_SYSCALL_INFO reported these > sign-extended 64-bit values, and the test complained about the mismatch. > > Fix this by passing arguments of the appropriate type to syscall(), > which is "unsigned long long" on MIPS n32, and __kernel_ulong_t on other > architectures. > > As a side effect, this also extends the test on all 64-bit architectures > by choosing constants that don't fit into 32-bit integers. > > Signed-off-by: Dmitry V. Levin <ldv@strace.io> > --- > > v2: Fixed MIPS #ifdef. > > .../selftests/ptrace/get_syscall_info.c | 53 +++++++++++-------- > 1 file changed, 32 insertions(+), 21 deletions(-) > > diff --git a/tools/testing/selftests/ptrace/get_syscall_info.c b/tools/testing/selftests/ptrace/get_syscall_info.c > index 5bcd1c7b5be6..2970f72d66d3 100644 > --- a/tools/testing/selftests/ptrace/get_syscall_info.c > +++ b/tools/testing/selftests/ptrace/get_syscall_info.c > @@ -11,8 +11,19 @@ > #include <err.h> > #include <signal.h> > #include <asm/unistd.h> > +#include <linux/types.h> > #include "linux/ptrace.h" > > +#if defined(_MIPS_SIM) && _MIPS_SIM == _MIPS_SIM_NABI32 > +/* > + * MIPS N32 is the only architecture where __kernel_ulong_t > + * does not match the bitness of syscall arguments. > + */ > +typedef unsigned long long kernel_ulong_t; > +#else > +typedef __kernel_ulong_t kernel_ulong_t; > +#endif > + What's the reason for adding these typedefs? checkpatch should have warned you about adding new typedefs. Also this introduces kernel_ulong_t in user-space test code. Something to avoid. > static int > kill_tracee(pid_t pid) > { > @@ -42,37 +53,37 @@ sys_ptrace(int request, pid_t pid, unsigned long addr, unsigned long data) > > TEST(get_syscall_info) > { > - static const unsigned long args[][7] = { > + const kernel_ulong_t args[][7] = { > /* a sequence of architecture-agnostic syscalls */ > { > __NR_chdir, > - (unsigned long) "", > - 0xbad1fed1, > - 0xbad2fed2, > - 0xbad3fed3, > - 0xbad4fed4, > - 0xbad5fed5 > + (uintptr_t) "", You could use ifdef here. > + (kernel_ulong_t) 0xdad1bef1bad1fed1ULL, > + (kernel_ulong_t) 0xdad2bef2bad2fed2ULL, > + (kernel_ulong_t) 0xdad3bef3bad3fed3ULL, > + (kernel_ulong_t) 0xdad4bef4bad4fed4ULL, > + (kernel_ulong_t) 0xdad5bef5bad5fed5ULL > }, > { > __NR_gettid, > - 0xcaf0bea0, > - 0xcaf1bea1, > - 0xcaf2bea2, > - 0xcaf3bea3, > - 0xcaf4bea4, > - 0xcaf5bea5 > + (kernel_ulong_t) 0xdad0bef0caf0bea0ULL, > + (kernel_ulong_t) 0xdad1bef1caf1bea1ULL, > + (kernel_ulong_t) 0xdad2bef2caf2bea2ULL, > + (kernel_ulong_t) 0xdad3bef3caf3bea3ULL, > + (kernel_ulong_t) 0xdad4bef4caf4bea4ULL, > + (kernel_ulong_t) 0xdad5bef5caf5bea5ULL > }, > { > __NR_exit_group, > 0, > - 0xfac1c0d1, > - 0xfac2c0d2, > - 0xfac3c0d3, > - 0xfac4c0d4, > - 0xfac5c0d5 > + (kernel_ulong_t) 0xdad1bef1fac1c0d1ULL, > + (kernel_ulong_t) 0xdad2bef2fac2c0d2ULL, > + (kernel_ulong_t) 0xdad3bef3fac3c0d3ULL, > + (kernel_ulong_t) 0xdad4bef4fac4c0d4ULL, > + (kernel_ulong_t) 0xdad5bef5fac5c0d5ULL > } > }; > - const unsigned long *exp_args; > + const kernel_ulong_t *exp_args; > > pid_t pid = fork(); > > @@ -154,7 +165,7 @@ TEST(get_syscall_info) > } > ASSERT_LT(0, (rc = sys_ptrace(PTRACE_GET_SYSCALL_INFO, > pid, size, > - (unsigned long) &info))) { > + (uintptr_t) &info))) { > LOG_KILL_TRACEE("PTRACE_GET_SYSCALL_INFO: %m"); > } > ASSERT_EQ(expected_none_size, rc) { > @@ -177,7 +188,7 @@ TEST(get_syscall_info) > case SIGTRAP | 0x80: > ASSERT_LT(0, (rc = sys_ptrace(PTRACE_GET_SYSCALL_INFO, > pid, size, > - (unsigned long) &info))) { > + (uintptr_t) &info))) { > LOG_KILL_TRACEE("PTRACE_GET_SYSCALL_INFO: %m"); > } > switch (ptrace_stop) { thanks, -- Shuah
On Sat, 29 Mar 2025, Dmitry V. Levin wrote: > > > +#if defined(_MIPS_SIM) && _MIPS_SIM == _MIPS_SIM_NABI32 > > > +/* > > > + * MIPS N32 is the only architecture where __kernel_ulong_t > > > + * does not match the bitness of syscall arguments. > > > + */ > > > +typedef unsigned long long kernel_ulong_t; > > > +#else > > > +typedef __kernel_ulong_t kernel_ulong_t; > > > +#endif > > > + > > > > What's the reason for adding these typedefs? checkpatch should > > have warned you about adding new typedefs. > > > > Also this introduces kernel_ulong_t in user-space test code. > > Something to avoid. > > There has to be a new type for this test, and the natural way to do this > is to use typedef. The alternative would be to #define kernel_ulong_t > which is ugly. By the way, there are quite a few typedefs in selftests, > and there seems to be given no rationale why adding new types in selftests > is a bad idea. FWIW I agree, and I fail to see a reason why this would be a problem in a standalone test program where the typedef does not propagate anywhere. The only potential issue I can identify would be a namespace clash, so perhaps the new type could have a name prefix specific to the test, but it doesn't appear to me a widespread practice across our selftests and then `kernel_' ought to be pretty safe against ISO C or POSIX, so perhaps let's leave the things alone? Maciej
On 3/29/25 08:02, Maciej W. Rozycki wrote: > On Sat, 29 Mar 2025, Dmitry V. Levin wrote: > >>>> +#if defined(_MIPS_SIM) && _MIPS_SIM == _MIPS_SIM_NABI32 >>>> +/* >>>> + * MIPS N32 is the only architecture where __kernel_ulong_t >>>> + * does not match the bitness of syscall arguments. >>>> + */ >>>> +typedef unsigned long long kernel_ulong_t; >>>> +#else >>>> +typedef __kernel_ulong_t kernel_ulong_t; >>>> +#endif >>>> + >>> >>> What's the reason for adding these typedefs? checkpatch should >>> have warned you about adding new typedefs. >>> >>> Also this introduces kernel_ulong_t in user-space test code. >>> Something to avoid. >> >> There has to be a new type for this test, and the natural way to do this >> is to use typedef. The alternative would be to #define kernel_ulong_t >> which is ugly. By the way, there are quite a few typedefs in selftests, >> and there seems to be given no rationale why adding new types in selftests >> is a bad idea. > It causes problems down the road for maintenance. I would rather not see these types of kernel typedefs added to user-space. > FWIW I agree, and I fail to see a reason why this would be a problem in a > standalone test program where the typedef does not propagate anywhere. > > The only potential issue I can identify would be a namespace clash, so > perhaps the new type could have a name prefix specific to the test, but it > doesn't appear to me a widespread practice across our selftests and then > `kernel_' ought to be pretty safe against ISO C or POSIX, so perhaps let's > leave the things alone? > Can't this be solved with ifdef? thanks, -- Shuah
diff --git a/tools/testing/selftests/ptrace/get_syscall_info.c b/tools/testing/selftests/ptrace/get_syscall_info.c index 5bcd1c7b5be6..2970f72d66d3 100644 --- a/tools/testing/selftests/ptrace/get_syscall_info.c +++ b/tools/testing/selftests/ptrace/get_syscall_info.c @@ -11,8 +11,19 @@ #include <err.h> #include <signal.h> #include <asm/unistd.h> +#include <linux/types.h> #include "linux/ptrace.h" +#if defined(_MIPS_SIM) && _MIPS_SIM == _MIPS_SIM_NABI32 +/* + * MIPS N32 is the only architecture where __kernel_ulong_t + * does not match the bitness of syscall arguments. + */ +typedef unsigned long long kernel_ulong_t; +#else +typedef __kernel_ulong_t kernel_ulong_t; +#endif + static int kill_tracee(pid_t pid) { @@ -42,37 +53,37 @@ sys_ptrace(int request, pid_t pid, unsigned long addr, unsigned long data) TEST(get_syscall_info) { - static const unsigned long args[][7] = { + const kernel_ulong_t args[][7] = { /* a sequence of architecture-agnostic syscalls */ { __NR_chdir, - (unsigned long) "", - 0xbad1fed1, - 0xbad2fed2, - 0xbad3fed3, - 0xbad4fed4, - 0xbad5fed5 + (uintptr_t) "", + (kernel_ulong_t) 0xdad1bef1bad1fed1ULL, + (kernel_ulong_t) 0xdad2bef2bad2fed2ULL, + (kernel_ulong_t) 0xdad3bef3bad3fed3ULL, + (kernel_ulong_t) 0xdad4bef4bad4fed4ULL, + (kernel_ulong_t) 0xdad5bef5bad5fed5ULL }, { __NR_gettid, - 0xcaf0bea0, - 0xcaf1bea1, - 0xcaf2bea2, - 0xcaf3bea3, - 0xcaf4bea4, - 0xcaf5bea5 + (kernel_ulong_t) 0xdad0bef0caf0bea0ULL, + (kernel_ulong_t) 0xdad1bef1caf1bea1ULL, + (kernel_ulong_t) 0xdad2bef2caf2bea2ULL, + (kernel_ulong_t) 0xdad3bef3caf3bea3ULL, + (kernel_ulong_t) 0xdad4bef4caf4bea4ULL, + (kernel_ulong_t) 0xdad5bef5caf5bea5ULL }, { __NR_exit_group, 0, - 0xfac1c0d1, - 0xfac2c0d2, - 0xfac3c0d3, - 0xfac4c0d4, - 0xfac5c0d5 + (kernel_ulong_t) 0xdad1bef1fac1c0d1ULL, + (kernel_ulong_t) 0xdad2bef2fac2c0d2ULL, + (kernel_ulong_t) 0xdad3bef3fac3c0d3ULL, + (kernel_ulong_t) 0xdad4bef4fac4c0d4ULL, + (kernel_ulong_t) 0xdad5bef5fac5c0d5ULL } }; - const unsigned long *exp_args; + const kernel_ulong_t *exp_args; pid_t pid = fork(); @@ -154,7 +165,7 @@ TEST(get_syscall_info) } ASSERT_LT(0, (rc = sys_ptrace(PTRACE_GET_SYSCALL_INFO, pid, size, - (unsigned long) &info))) { + (uintptr_t) &info))) { LOG_KILL_TRACEE("PTRACE_GET_SYSCALL_INFO: %m"); } ASSERT_EQ(expected_none_size, rc) { @@ -177,7 +188,7 @@ TEST(get_syscall_info) case SIGTRAP | 0x80: ASSERT_LT(0, (rc = sys_ptrace(PTRACE_GET_SYSCALL_INFO, pid, size, - (unsigned long) &info))) { + (uintptr_t) &info))) { LOG_KILL_TRACEE("PTRACE_GET_SYSCALL_INFO: %m"); } switch (ptrace_stop) {
MIPS n32 is one of two ILP32 architectures supported by the kernel that have 64-bit syscall arguments (another one is x32). When this test passed 32-bit arguments to syscall(), they were sign-extended in libc, PTRACE_GET_SYSCALL_INFO reported these sign-extended 64-bit values, and the test complained about the mismatch. Fix this by passing arguments of the appropriate type to syscall(), which is "unsigned long long" on MIPS n32, and __kernel_ulong_t on other architectures. As a side effect, this also extends the test on all 64-bit architectures by choosing constants that don't fit into 32-bit integers. Signed-off-by: Dmitry V. Levin <ldv@strace.io> --- v2: Fixed MIPS #ifdef. .../selftests/ptrace/get_syscall_info.c | 53 +++++++++++-------- 1 file changed, 32 insertions(+), 21 deletions(-)