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Revert "tracing: Add "(fault)" name injection to kernel probes"

This reverts commit 2e9906f84fc7c99388bb7123ade167250d50f1c0. It was turned out that commit 2e9906f84fc7 ("tracing: Add "(fault)" name injection to kernel probes") did not work correctly and probe events still show just '(fault)' (instead of '"(fault)"'). Also, current '(fault)' is more explicit that it faulted. This also moves FAULT_STRING macro to trace.h so that synthetic event can keep using it, and uses it in trace_probe.c too. Link: https://lore.kernel.org/all/168908495772.123124.1250788051922100079.stgit@devnote2/ Link: https://lore.kernel.org/all/20230706230642.3793a593@rorschach.local.home/

Masami Hiramatsu (Google) committed 3 years ago

Commit 4ed8f331 parent e38e2c63 files · +9 −26Browse files

Unified · Split

3 files
  1. kernel/trace/trace.h +2 −0
  2. kernel/trace/trace_probe.c +1 −1
  3. kernel/trace/trace_probe_kernel.h +6 −25
kernel/trace/trace.h+2−0
@@ -113,6 +113,8 @@ enum trace_type { · 112 unmodified lines
113#define MEM_FAIL(condition, fmt, ...) \113#define MEM_FAIL(condition, fmt, ...) \
114 DO_ONCE_LITE_IF(condition, pr_err, "ERROR: " fmt, ##__VA_ARGS__)114 DO_ONCE_LITE_IF(condition, pr_err, "ERROR: " fmt, ##__VA_ARGS__)
115 115
116#define FAULT_STRING "(fault)"
117
116#define HIST_STACKTRACE_DEPTH 16118#define HIST_STACKTRACE_DEPTH 16
117#define HIST_STACKTRACE_SIZE (HIST_STACKTRACE_DEPTH * sizeof(unsigned long))119#define HIST_STACKTRACE_SIZE (HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
118#define HIST_STACKTRACE_SKIP 5120#define HIST_STACKTRACE_SKIP 5
kernel/trace/trace_probe.c+1−1
@@ -65,7 +65,7 @@ int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent) · 64 unmodified lines
65 int len = *(u32 *)data >> 16;65 int len = *(u32 *)data >> 16;
66 66
67 if (!len)67 if (!len)
68 trace_seq_puts(s, "(fault)");68 trace_seq_puts(s, FAULT_STRING);
69 else69 else
70 trace_seq_printf(s, "\"%s\"",70 trace_seq_printf(s, "\"%s\"",
71 (const char *)get_loc_data(data, ent));71 (const char *)get_loc_data(data, ent));
kernel/trace/trace_probe_kernel.h+6−25
@@ -2,8 +2,6 @@ · 1 unmodified line
2#ifndef __TRACE_PROBE_KERNEL_H_2#ifndef __TRACE_PROBE_KERNEL_H_
3#define __TRACE_PROBE_KERNEL_H_3#define __TRACE_PROBE_KERNEL_H_
4 4
5#define FAULT_STRING "(fault)"
6
7/*5/*
8 * This depends on trace_probe.h, but can not include it due to6 * This depends on trace_probe.h, but can not include it due to
9 * the way trace_probe_tmpl.h is used by trace_kprobe.c and trace_eprobe.c.7 * the way trace_probe_tmpl.h is used by trace_kprobe.c and trace_eprobe.c.
@@ -15,16 +13,8 @@ static nokprobe_inline int · 5 unmodified lines
15fetch_store_strlen_user(unsigned long addr)13fetch_store_strlen_user(unsigned long addr)
16{14{
17 const void __user *uaddr = (__force const void __user *)addr;15 const void __user *uaddr = (__force const void __user *)addr;
18 int ret;
19 16
20 ret = strnlen_user_nofault(uaddr, MAX_STRING_SIZE);17 return strnlen_user_nofault(uaddr, MAX_STRING_SIZE);
21 /*
22 * strnlen_user_nofault returns zero on fault, insert the
23 * FAULT_STRING when that occurs.
24 */
25 if (ret <= 0)
26 return strlen(FAULT_STRING) + 1;
27 return ret;
28}18}
29 19
30/* Return the length of string -- including null terminal byte */20/* Return the length of string -- including null terminal byte */
@@ -44,18 +34,7 @@ fetch_store_strlen(unsigned long addr) · 13 unmodified lines
44 len++;34 len++;
45 } while (c && ret == 0 && len < MAX_STRING_SIZE);35 } while (c && ret == 0 && len < MAX_STRING_SIZE);
46 36
47 /* For faults, return enough to hold the FAULT_STRING */37 return (ret < 0) ? ret : len;
48 return (ret < 0) ? strlen(FAULT_STRING) + 1 : len;
49}
50
51static nokprobe_inline void set_data_loc(int ret, void *dest, void *__dest, void *base, int len)
52{
53 if (ret >= 0) {
54 *(u32 *)dest = make_data_loc(ret, __dest - base);
55 } else {
56 strscpy(__dest, FAULT_STRING, len);
57 ret = strlen(__dest) + 1;
58 }
59}38}
60 39
61/*40/*
@@ -76,7 +55,8 @@ fetch_store_string_user(unsigned long addr, void *dest, void *base) · 14 unmodified lines
76 __dest = get_loc_data(dest, base);55 __dest = get_loc_data(dest, base);
77 56
78 ret = strncpy_from_user_nofault(__dest, uaddr, maxlen);57 ret = strncpy_from_user_nofault(__dest, uaddr, maxlen);
79 set_data_loc(ret, dest, __dest, base, maxlen);58 if (ret >= 0)
59 *(u32 *)dest = make_data_loc(ret, __dest - base);
80 60
81 return ret;61 return ret;
82}62}
@@ -107,7 +87,8 @@ fetch_store_string(unsigned long addr, void *dest, void *base) · 24 unmodified lines
107 * probing.87 * probing.
108 */88 */
109 ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen);89 ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen);
110 set_data_loc(ret, dest, __dest, base, maxlen);90 if (ret >= 0)
91 *(u32 *)dest = make_data_loc(ret, __dest - base);
111 92
112 return ret;93 return ret;
113}94}