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Diffstat (limited to 'Documentation/powerpc/syscall64-abi.rst')
| -rw-r--r-- | Documentation/powerpc/syscall64-abi.rst | 10 |
1 files changed, 10 insertions, 0 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 ======== |