[strace/strace] [RFC] Add 64-bit LoongArch support (PR #205)

Dmitry V. Levin notifications at github.com
Sun Jan 9 01:48:49 UTC 2022

> Hmm, can we keep do_syscall() as is and solve the ptrace problem by overriding arch_syscall_enter_tracehook() like this?
> static inline __must_check int arch_syscall_enter_tracehook(struct pt_regs *regs) {
> ```
>     ret = tracehook_report_syscall_entry(regs);
>     if (ret)
>             syscall_set_return_value(current, current_pt_regs(), -ENOSYS, 0);

It's better to use `regs` instead of `current_pt_regs()` here.

>     return ret;
> ```
> }

No, this cannot help to solve the problem because syscall tampering doesn't make `tracehook_report_syscall_entry` return a nonzero value.

However, this approach makes sense for a different reason - the lengthy comment before `tracehook_report_syscall_entry` says:
_Returns zero normally, or nonzero if the calling arch code should abort the system call.  That must prevent normal entry so no system call is made. If @task ever returns to user mode after this, its register state is unspecified, but should be something harmless like an %ENOSYS error return._

Reply to this email directly or view it on GitHub:
You are receiving this because you are subscribed to this thread.

Message ID: <strace/strace/pull/205/c1008210169 at github.com>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.strace.io/pipermail/strace-devel/attachments/20220108/b2ee3091/attachment.htm>

More information about the Strace-devel mailing list