On 2025/11/24 23:23, Kevin Brodsky wrote:

On 24/11/2025 10:34, Jinjie Ruan wrote:

quoted

On 2025/11/19 1:13, Kevin Brodsky wrote:

quoted

On 17/11/2025 14:30, Jinjie Ruan wrote:

quoted

[...]

diff --git a/kernel/entry/syscall-common.c b/kernel/entry/syscall-common.c
index 66e6ba7fa80c..27310e611567 100644
--- a/kernel/entry/syscall-common.c
+++ b/kernel/entry/syscall-common.c

@@ -17,6 +17,25 @@ static inline void syscall_enter_audit(struct pt_regs *regs, long syscall)
 	}
 }
 
+/**
+ * arch_ptrace_report_syscall_entry - Architecture specific
+ *				      ptrace_report_syscall_entry().
+ *
+ * Invoked from syscall_trace_enter() to wrap ptrace_report_syscall_entry().
+ * Defaults to ptrace_report_syscall_entry.
+ *
+ * The main purpose is to support arch-specific ptrace_report_syscall_entry()
+ * implementation.
+ */
+static __always_inline int arch_ptrace_report_syscall_entry(struct pt_regs *regs);
+
+#ifndef arch_ptrace_report_syscall_entry
+static __always_inline int arch_ptrace_report_syscall_entry(struct pt_regs *regs)
+{
+	return ptrace_report_syscall_entry(regs);

I saw that Thomas suggested this approach on v4, and it makes sense to
me, but I find the naming surprising. If an architecture does need extra
handling, then the generic function should never be called from generic
code. So it seems to me that the more logical change would be:

* Rename: ptrace_report_syscall_entry -> __ptrace_report_syscall_entry
* Introduce ptrace_report_syscall_entry(), defaults to
__ptrace_report_syscall_entry()

If ptrace_report_syscall_entry() is defined in linux/ptrace.h, and an
architecture also needs to redefine this function, but the
architecture's own <asm/entry-common.h> must include <linux/ptrace.h>,
the function will end up being defined twice and cause a "duplicate
definition" compile error.

There's plenty of arch-defined functions in <linux/ptrace.h> already.
__ptrace_report_syscall_entry() should be defined inside an #ifndef and
architectures can define their own implementation in <asm/ptrace.h>,
like force_successful_syscall_return() for instance.

Shared functions like ptrace_report_syscall() are all defined in
<linux/ptrace.h>.
When we want to override __ptrace_report_syscall_entry() in
<asm/ptrace.h> we still have to include <linux/ptrace.h> again,then the
redefine problem occurs again.

What we actually need to reuse is ptrace_report_syscall_entry() (or
__ptrace_report_syscall_entry()).

The arch version need to reuse and wrap ptrace_report_syscall_entry(),
because for instance arm64 needs to perform additional operations before
and after this step. Therefore, I believe the current implementation is
appropriate.

- Kevin

quoted

quoted

All this would be done in <linux/ptrace.h>, where it clearly belongs.
The __ prefix makes it clear that the generic function is not the main
interface. Even better, no need to change any caller with that approach.

- Kevin

quoted

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