diff options
| -rw-r--r-- | Documentation/powerpc/syscall64-abi.rst | 10 | ||||
| -rw-r--r-- | tools/testing/selftests/seccomp/seccomp_bpf.c | 27 |
2 files changed, 28 insertions, 9 deletions
diff --git a/Documentation/powerpc/syscall64-abi.rst b/Documentation/powerpc/syscall64-abi.rst index dabee3729e5a..56490c4c0c07 100644 --- a/Documentation/powerpc/syscall64-abi.rst +++ b/Documentation/powerpc/syscall64-abi.rst @@ -109,6 +109,16 @@ auxiliary vector. scv 0 syscalls will always behave as PPC_FEATURE2_HTM_NOSC. +ptrace +------ +When ptracing system calls (PTRACE_SYSCALL), the pt_regs.trap value contains +the system call type that can be used to distinguish between sc and scv 0 +system calls, and the different register conventions can be accounted for. + +If the value of (pt_regs.trap & 0xfff0) is 0xc00 then the system call was +performed with the sc instruction, if it is 0x3000 then the system call was +performed with the scv 0 instruction. + vsyscall ======== diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index 98c3b647f54d..e3d5c77a8612 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -1753,16 +1753,25 @@ TEST_F(TRACE_poke, getpid_runs_normally) # define SYSCALL_RET_SET(_regs, _val) \ do { \ typeof(_val) _result = (_val); \ - /* \ - * A syscall error is signaled by CR0 SO bit \ - * and the code is stored as a positive value. \ - */ \ - if (_result < 0) { \ - SYSCALL_RET(_regs) = -_result; \ - (_regs).ccr |= 0x10000000; \ - } else { \ + if ((_regs.trap & 0xfff0) == 0x3000) { \ + /* \ + * scv 0 system call uses -ve result \ + * for error, so no need to adjust. \ + */ \ SYSCALL_RET(_regs) = _result; \ - (_regs).ccr &= ~0x10000000; \ + } else { \ + /* \ + * A syscall error is signaled by the \ + * CR0 SO bit and the code is stored as \ + * a positive value. \ + */ \ + if (_result < 0) { \ + SYSCALL_RET(_regs) = -_result; \ + (_regs).ccr |= 0x10000000; \ + } else { \ + SYSCALL_RET(_regs) = _result; \ + (_regs).ccr &= ~0x10000000; \ + } \ } \ } while (0) # define SYSCALL_RET_SET_ON_PTRACE_EXIT |