From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
Date: Wed, 12 Oct 2022 06:40:56 -0400
Subject: tracing: Move duplicate code of trace_kprobe/eprobe.c into header
Git-commit: f1d3cbfaafc10464550c6d3a125f4fc802bbaed5
Patch-mainline: v6.1-rc1
References: git-fixes
The functions:
fetch_store_strlen_user()
fetch_store_strlen()
fetch_store_string_user()
fetch_store_string()
are identical in both trace_kprobe.c and trace_eprobe.c. Move them into
a new header file trace_probe_kernel.h to share it. This code will later
be used by the synthetic events as well.
Marked for stable as a fix for a crash in synthetic events requires it.
Link: https://lkml.kernel.org/r/20221012104534.467668078@goodmis.org
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Fixes: bd82631d7ccdc ("tracing: Add support for dynamic strings to synthetic events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
[ppavlu: Drop updates to kernel/trace/trace_eprobe.c because we don't
have the new eprobes functionality which was added in
commit 7491e2c44278 ("tracing: Add a probe that attaches to trace events").]
Acked-by: Petr Pavlu <petr.pavlu@suse.com>
---
kernel/trace/trace_eprobe.c | 60 ++----------------------
kernel/trace/trace_kprobe.c | 60 ++----------------------
kernel/trace/trace_probe_kernel.h | 96 +++++++++++++++++++++++++++++++++++++++
3 files changed, 106 insertions(+), 110 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 23f7f0ec4f4c..5a75b039e586 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -20,6 +20,7 @@
#include "trace_kprobe_selftest.h"
#include "trace_probe.h"
#include "trace_probe_tmpl.h"
+#include "trace_probe_kernel.h"
#define KPROBE_EVENT_SYSTEM "kprobes"
#define KRETPROBE_MAXACTIVE_MAX 4096
@@ -1223,29 +1224,14 @@ static const struct file_operations kprobe_profile_ops = {
static nokprobe_inline int
fetch_store_strlen_user(unsigned long addr)
{
- const void __user *uaddr = (__force const void __user *)addr;
-
- return strnlen_user_nofault(uaddr, MAX_STRING_SIZE);
+ return kern_fetch_store_strlen_user(addr);
}
/* Return the length of string -- including null terminal byte */
static nokprobe_inline int
fetch_store_strlen(unsigned long addr)
{
- int ret, len = 0;
- u8 c;
-
-#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
- if (addr < TASK_SIZE)
- return fetch_store_strlen_user(addr);
-#endif
-
- do {
- ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1);
- len++;
- } while (c && ret == 0 && len < MAX_STRING_SIZE);
-
- return (ret < 0) ? ret : len;
+ return kern_fetch_store_strlen(addr);
}
/*
@@ -1255,21 +1241,7 @@ fetch_store_strlen(unsigned long addr)
static nokprobe_inline int
fetch_store_string_user(unsigned long addr, void *dest, void *base)
{
- const void __user *uaddr = (__force const void __user *)addr;
- int maxlen = get_loc_len(*(u32 *)dest);
- void *__dest;
- long ret;
-
- if (unlikely(!maxlen))
- return -ENOMEM;
-
- __dest = get_loc_data(dest, base);
-
- ret = strncpy_from_user_nofault(__dest, uaddr, maxlen);
- if (ret >= 0)
- *(u32 *)dest = make_data_loc(ret, __dest - base);
-
- return ret;
+ return kern_fetch_store_string_user(addr, dest, base);
}
/*
@@ -1279,29 +1251,7 @@ fetch_store_string_user(unsigned long addr, void *dest, void *base)
static nokprobe_inline int
fetch_store_string(unsigned long addr, void *dest, void *base)
{
- int maxlen = get_loc_len(*(u32 *)dest);
- void *__dest;
- long ret;
-
-#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
- if ((unsigned long)addr < TASK_SIZE)
- return fetch_store_string_user(addr, dest, base);
-#endif
-
- if (unlikely(!maxlen))
- return -ENOMEM;
-
- __dest = get_loc_data(dest, base);
-
- /*
- * Try to get string again, since the string can be changed while
- * probing.
- */
- ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen);
- if (ret >= 0)
- *(u32 *)dest = make_data_loc(ret, __dest - base);
-
- return ret;
+ return kern_fetch_store_string(addr, dest, base);
}
static nokprobe_inline int
diff --git a/kernel/trace/trace_probe_kernel.h b/kernel/trace/trace_probe_kernel.h
new file mode 100644
index 000000000000..1d43df29a1f8
--- /dev/null
+++ b/kernel/trace/trace_probe_kernel.h
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __TRACE_PROBE_KERNEL_H_
+#define __TRACE_PROBE_KERNEL_H_
+
+/*
+ * This depends on trace_probe.h, but can not include it due to
+ * the way trace_probe_tmpl.h is used by trace_kprobe.c and trace_eprobe.c.
+ * Which means that any other user must include trace_probe.h before including
+ * this file.
+ */
+/* Return the length of string -- including null terminal byte */
+static nokprobe_inline int
+kern_fetch_store_strlen_user(unsigned long addr)
+{
+ const void __user *uaddr = (__force const void __user *)addr;
+
+ return strnlen_user_nofault(uaddr, MAX_STRING_SIZE);
+}
+
+/* Return the length of string -- including null terminal byte */
+static nokprobe_inline int
+kern_fetch_store_strlen(unsigned long addr)
+{
+ int ret, len = 0;
+ u8 c;
+
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+ if (addr < TASK_SIZE)
+ return kern_fetch_store_strlen_user(addr);
+#endif
+
+ do {
+ ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1);
+ len++;
+ } while (c && ret == 0 && len < MAX_STRING_SIZE);
+
+ return (ret < 0) ? ret : len;
+}
+
+/*
+ * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
+ * with max length and relative data location.
+ */
+static nokprobe_inline int
+kern_fetch_store_string_user(unsigned long addr, void *dest, void *base)
+{
+ const void __user *uaddr = (__force const void __user *)addr;
+ int maxlen = get_loc_len(*(u32 *)dest);
+ void *__dest;
+ long ret;
+
+ if (unlikely(!maxlen))
+ return -ENOMEM;
+
+ __dest = get_loc_data(dest, base);
+
+ ret = strncpy_from_user_nofault(__dest, uaddr, maxlen);
+ if (ret >= 0)
+ *(u32 *)dest = make_data_loc(ret, __dest - base);
+
+ return ret;
+}
+
+/*
+ * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
+ * length and relative data location.
+ */
+static nokprobe_inline int
+kern_fetch_store_string(unsigned long addr, void *dest, void *base)
+{
+ int maxlen = get_loc_len(*(u32 *)dest);
+ void *__dest;
+ long ret;
+
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+ if ((unsigned long)addr < TASK_SIZE)
+ return kern_fetch_store_string_user(addr, dest, base);
+#endif
+
+ if (unlikely(!maxlen))
+ return -ENOMEM;
+
+ __dest = get_loc_data(dest, base);
+
+ /*
+ * Try to get string again, since the string can be changed while
+ * probing.
+ */
+ ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen);
+ if (ret >= 0)
+ *(u32 *)dest = make_data_loc(ret, __dest - base);
+
+ return ret;
+}
+
+#endif /* __TRACE_PROBE_KERNEL_H_ */