ftrace creates entries for each syscall in the tracefs but has failed
since commit 08d0ce30e0e4 ("riscv: Implement syscall wrappers") which
prefixes all riscv syscalls with __riscv_.
So fix this by implementing arch_syscall_match_sym_name() which allows us
to ignore this prefix.
And also ignore compat syscalls like x86/arm64 by implementing
arch_trace_is_compat_syscall().
Fixes: 08d0ce30e0e4 ("riscv: Implement syscall wrappers")
Signed-off-by: Alexandre Ghiti <[email protected]>
---
arch/riscv/include/asm/ftrace.h | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h
index 740a979171e5..2b2f5df7ef2c 100644
--- a/arch/riscv/include/asm/ftrace.h
+++ b/arch/riscv/include/asm/ftrace.h
@@ -31,6 +31,27 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
return addr;
}
+/*
+ * Let's do like x86/arm64 and ignore the compat syscalls.
+ */
+#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
+static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
+{
+ return is_compat_task();
+}
+
+#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
+static inline bool arch_syscall_match_sym_name(const char *sym,
+ const char *name)
+{
+ /*
+ * Since all syscall functions have __riscv_ prefix, we must skip it.
+ * However, as we described above, we decided to ignore compat
+ * syscalls, so we don't care about __riscv_compat_ prefix here.
+ */
+ return !strcmp(sym + 8, name);
+}
+
struct dyn_arch_ftrace {
};
#endif
--
2.39.2
@Conor Dooley This fails checkpatch but the documentation here states
that this is how to do:
https://elixir.bootlin.com/linux/latest/source/Documentation/trace/ftrace-design.rst#L246
On Tue, Oct 3, 2023 at 8:24 PM Alexandre Ghiti <[email protected]> wrote:
>
> ftrace creates entries for each syscall in the tracefs but has failed
> since commit 08d0ce30e0e4 ("riscv: Implement syscall wrappers") which
> prefixes all riscv syscalls with __riscv_.
>
> So fix this by implementing arch_syscall_match_sym_name() which allows us
> to ignore this prefix.
>
> And also ignore compat syscalls like x86/arm64 by implementing
> arch_trace_is_compat_syscall().
>
> Fixes: 08d0ce30e0e4 ("riscv: Implement syscall wrappers")
> Signed-off-by: Alexandre Ghiti <[email protected]>
> ---
> arch/riscv/include/asm/ftrace.h | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h
> index 740a979171e5..2b2f5df7ef2c 100644
> --- a/arch/riscv/include/asm/ftrace.h
> +++ b/arch/riscv/include/asm/ftrace.h
> @@ -31,6 +31,27 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
> return addr;
> }
>
> +/*
> + * Let's do like x86/arm64 and ignore the compat syscalls.
> + */
> +#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
> +static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
> +{
> + return is_compat_task();
> +}
> +
> +#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
> +static inline bool arch_syscall_match_sym_name(const char *sym,
> + const char *name)
> +{
> + /*
> + * Since all syscall functions have __riscv_ prefix, we must skip it.
> + * However, as we described above, we decided to ignore compat
> + * syscalls, so we don't care about __riscv_compat_ prefix here.
> + */
> + return !strcmp(sym + 8, name);
> +}
> +
> struct dyn_arch_ftrace {
> };
> #endif
> --
> 2.39.2
>
On Tue, Oct 3, 2023 at 11:24 AM Alexandre Ghiti <[email protected]> wrote:
>
> ftrace creates entries for each syscall in the tracefs but has failed
> since commit 08d0ce30e0e4 ("riscv: Implement syscall wrappers") which
> prefixes all riscv syscalls with __riscv_.
>
> So fix this by implementing arch_syscall_match_sym_name() which allows us
> to ignore this prefix.
>
> And also ignore compat syscalls like x86/arm64 by implementing
> arch_trace_is_compat_syscall().
>
> Fixes: 08d0ce30e0e4 ("riscv: Implement syscall wrappers")
> Signed-off-by: Alexandre Ghiti <[email protected]>
> ---
> arch/riscv/include/asm/ftrace.h | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h
> index 740a979171e5..2b2f5df7ef2c 100644
> --- a/arch/riscv/include/asm/ftrace.h
> +++ b/arch/riscv/include/asm/ftrace.h
> @@ -31,6 +31,27 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
> return addr;
> }
>
> +/*
> + * Let's do like x86/arm64 and ignore the compat syscalls.
> + */
> +#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
> +static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
> +{
> + return is_compat_task();
> +}
> +
> +#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
> +static inline bool arch_syscall_match_sym_name(const char *sym,
> + const char *name)
> +{
> + /*
> + * Since all syscall functions have __riscv_ prefix, we must skip it.
> + * However, as we described above, we decided to ignore compat
> + * syscalls, so we don't care about __riscv_compat_ prefix here.
> + */
> + return !strcmp(sym + 8, name);
> +}
Good catch, thanks for fixing this!
Reviewed-by: Sami Tolvanen <[email protected]>
Sami
On Tue, 3 Oct 2023 20:24:07 +0200
Alexandre Ghiti <[email protected]> wrote:
> ftrace creates entries for each syscall in the tracefs but has failed
> since commit 08d0ce30e0e4 ("riscv: Implement syscall wrappers") which
> prefixes all riscv syscalls with __riscv_.
>
> So fix this by implementing arch_syscall_match_sym_name() which allows us
> to ignore this prefix.
>
> And also ignore compat syscalls like x86/arm64 by implementing
> arch_trace_is_compat_syscall().
>
Looks good to me,
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Thank you,
> Fixes: 08d0ce30e0e4 ("riscv: Implement syscall wrappers")
> Signed-off-by: Alexandre Ghiti <[email protected]>
> ---
> arch/riscv/include/asm/ftrace.h | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h
> index 740a979171e5..2b2f5df7ef2c 100644
> --- a/arch/riscv/include/asm/ftrace.h
> +++ b/arch/riscv/include/asm/ftrace.h
> @@ -31,6 +31,27 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
> return addr;
> }
>
> +/*
> + * Let's do like x86/arm64 and ignore the compat syscalls.
> + */
> +#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
> +static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
> +{
> + return is_compat_task();
> +}
> +
> +#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
> +static inline bool arch_syscall_match_sym_name(const char *sym,
> + const char *name)
> +{
> + /*
> + * Since all syscall functions have __riscv_ prefix, we must skip it.
> + * However, as we described above, we decided to ignore compat
> + * syscalls, so we don't care about __riscv_compat_ prefix here.
> + */
> + return !strcmp(sym + 8, name);
> +}
> +
> struct dyn_arch_ftrace {
> };
> #endif
> --
> 2.39.2
>
--
Masami Hiramatsu (Google) <[email protected]>
Alexandre Ghiti <[email protected]> writes:
> @Conor Dooley This fails checkpatch but the documentation here states
> that this is how to do:
> https://elixir.bootlin.com/linux/latest/source/Documentation/trace/ftrace-design.rst#L246
FWIW, I'll relax the PW CI checkpatch test going forward. It's way too
strict...
Alexandre Ghiti <[email protected]> writes:
> ftrace creates entries for each syscall in the tracefs but has failed
> since commit 08d0ce30e0e4 ("riscv: Implement syscall wrappers") which
> prefixes all riscv syscalls with __riscv_.
>
> So fix this by implementing arch_syscall_match_sym_name() which allows us
> to ignore this prefix.
>
> And also ignore compat syscalls like x86/arm64 by implementing
> arch_trace_is_compat_syscall().
>
> Fixes: 08d0ce30e0e4 ("riscv: Implement syscall wrappers")
> Signed-off-by: Alexandre Ghiti <[email protected]>
This fix does the BPF test suite happier!
Tested-by: Björn Töpel <[email protected]>
Hello:
This patch was applied to riscv/linux.git (fixes)
by Palmer Dabbelt <[email protected]>:
On Tue, 3 Oct 2023 20:24:07 +0200 you wrote:
> ftrace creates entries for each syscall in the tracefs but has failed
> since commit 08d0ce30e0e4 ("riscv: Implement syscall wrappers") which
> prefixes all riscv syscalls with __riscv_.
>
> So fix this by implementing arch_syscall_match_sym_name() which allows us
> to ignore this prefix.
>
> [...]
Here is the summary with links:
- [-fixes] riscv: Fix ftrace syscall handling which are now prefixed with __riscv_
https://git.kernel.org/riscv/c/a87e7d3e8832
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html