On 2025-01-10 11:34, Charlie Jenkins wrote: > On Thu, Dec 26, 2024 at 11:21:59PM +0800, Celeste Liu wrote: >> >> On 2024-12-26 21:35, Dmitry V. Levin wrote: >>> On Thu, Dec 26, 2024 at 06:52:52PM +0800, Celeste Liu wrote: >>>> This test checks that orig_a0 allows a syscall argument to be modified, >>>> and that changing a0 does not change the syscall argument. >>>> >>>> Co-developed-by: Quan Zhou <[email protected]> >>>> Signed-off-by: Quan Zhou <[email protected]> >>>> Co-developed-by: Charlie Jenkins <[email protected]> >>>> Signed-off-by: Charlie Jenkins <[email protected]> >>>> Reviewed-by: Björn Töpel <[email protected]> >>>> Signed-off-by: Celeste Liu <[email protected]> >>> [...] >>>> diff --git a/tools/testing/selftests/riscv/abi/ptrace.c >>>> b/tools/testing/selftests/riscv/abi/ptrace.c >>>> new file mode 100644 >>>> index >>>> 0000000000000000000000000000000000000000..023695352215bb5de3f91c1a6f5ea3b4f9373ff9 >>>> --- /dev/null >>>> +++ b/tools/testing/selftests/riscv/abi/ptrace.c >>> [...] >>>> + if (ptrace(PTRACE_GET_SYSCALL_INFO, pid, PTRACE_SYSCALL_INFO_ENTRY, >>>> &syscall_info_entry)) >>>> + perr_and_exit("failed to get syscall info of entry\n"); >>>> + result->orig_a0 = syscall_info_entry->entry.args[0]; >>>> + if (ptrace(PTRACE_GET_SYSCALL_INFO, pid, PTRACE_SYSCALL_INFO_EXIT, >>>> &syscall_info_exit)) >>>> + perr_and_exit("failed to get syscall info of exit\n"); >>>> + result->a0 = syscall_info_exit->exit.rval; >>> >>> I'm sorry but this is not how PTRACE_GET_SYSCALL_INFO should be used. >>> >>> PTRACE_GET_SYSCALL_INFO operation takes a pointer and a size, >>> and in this example instead of size you pass constants 1 and 2, which >>> essentially means that both syscall_info_entry->entry.args[0] and >>> syscall_info_exit->exit.rval are not going to be assigned >>> and would just contain some garbage from the stack. >>> >>> Also, PTRACE_GET_SYSCALL_INFO operation returns the number of bytes >>> available to be written by the kernel, which is always nonzero on any >>> PTRACE_GET_SYSCALL_INFO-capable kernel. In other words, this example >>> will always end up with perr_and_exit() call. >>> >>> I wonder how this test was tested before the submission. >> >> Oops... It seems I forget sync the code to test board so it runs with the >> old code... >> The code is completely not tested... >> I'm so sorry for my mistake. >> >> I will correct it and test it carefully later... > > It would be great to get this into 6.14. Let me know if you would like > any help!
v5 has been sent. Sorry for delay. My test environment was broken yesterday so I have to spend time to repair it first... https://lore.kernel.org/lkml/[email protected]/T/ > > - Charlie > >> >>> >>> >>
