From a87e7d3e8832271ecb7d5eaaabc5b49fe25a469b Mon Sep 17 00:00:00 2001
From: Alexandre Ghiti <alexghiti@rivosinc.com>
Date: Tue, 3 Oct 2023 20:24:07 +0200
Subject: [PATCH] riscv: Fix ftrace syscall handling which are now prefixed
with __riscv_
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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 <alexghiti@rivosinc.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20231003182407.32198-1-alexghiti@rivosinc.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
---
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 740a979171e56..2b2f5df7ef2c7 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
--
2.30.2