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-rw-r--r--Documentation/trace/kprobetrace.rst9
-rw-r--r--kernel/trace/trace.c2
-rw-r--r--kernel/trace/trace_kprobe.c42
-rw-r--r--kernel/trace/trace_probe.c14
-rw-r--r--kernel/trace/trace_probe.h1
-rw-r--r--kernel/trace/trace_probe_tmpl.h14
-rw-r--r--kernel/trace/trace_uprobe.c12
7 files changed, 84 insertions, 10 deletions
diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst
index 235ce2ab131a..a3ac7c9ac242 100644
--- a/Documentation/trace/kprobetrace.rst
+++ b/Documentation/trace/kprobetrace.rst
@@ -55,7 +55,8 @@ Synopsis of kprobe_events
NAME=FETCHARG : Set NAME as the argument name of FETCHARG.
FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types
(u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal types
- (x8/x16/x32/x64), "string" and bitfield are supported.
+ (x8/x16/x32/x64), "string", "ustring" and bitfield
+ are supported.
(\*1) only for the probe on function entry (offs == 0).
(\*2) only for return probe.
@@ -77,7 +78,11 @@ apply it to registers/stack-entries etc. (for example, '$stack1:x8[8]' is
wrong, but '+8($stack):x8[8]' is OK.)
String type is a special type, which fetches a "null-terminated" string from
kernel space. This means it will fail and store NULL if the string container
-has been paged out.
+has been paged out. "ustring" type is an alternative of string for user-space.
+Note that kprobe-event provides string/ustring types, but doesn't change it
+automatically. So user has to decide if the targe string in kernel or in user
+space carefully. On some arch, if you choose wrong one, it always fails to
+record string data.
The string array type is a bit different from other types. For other base
types, <base-type>[1] is equal to <base-type> (e.g. +0(%di):x32[1] is same
as +0(%di):x32.) But string[1] is not equal to string. The string type itself
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1c80521fd436..d3a477a16e70 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4847,7 +4847,7 @@ static const char readme_msg[] =
"\t $stack<index>, $stack, $retval, $comm\n"
#endif
"\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n"
- "\t b<bit-width>@<bit-offset>/<container-size>,\n"
+ "\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n"
"\t <type>\\[<array-size>\\]\n"
#ifdef CONFIG_HIST_TRIGGERS
"\t field: <stype> <name>;\n"
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 7d736248a070..439bf04d14ce 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -886,6 +886,15 @@ fetch_store_strlen(unsigned long addr)
return (ret < 0) ? ret : len;
}
+/* Return the length of string -- including null terminal byte */
+static nokprobe_inline int
+fetch_store_strlen_user(unsigned long addr)
+{
+ const void __user *uaddr = (__force const void __user *)addr;
+
+ return strnlen_unsafe_user(uaddr, MAX_STRING_SIZE);
+}
+
/*
* Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
* length and relative data location.
@@ -894,19 +903,46 @@ static nokprobe_inline int
fetch_store_string(unsigned long addr, void *dest, void *base)
{
int maxlen = get_loc_len(*(u32 *)dest);
- u8 *dst = get_loc_data(dest, base);
+ void *__dest;
long ret;
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_unsafe(dst, (void *)addr, maxlen);
+ ret = strncpy_from_unsafe(__dest, (void *)addr, maxlen);
+ if (ret >= 0)
+ *(u32 *)dest = make_data_loc(ret, __dest - base);
+
+ return ret;
+}
+/*
+ * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
+ * with max length and relative data location.
+ */
+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_unsafe_user(__dest, uaddr, maxlen);
if (ret >= 0)
- *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
+ *(u32 *)dest = make_data_loc(ret, __dest - base);
+
return ret;
}
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index a347faced959..5a0470f7b9de 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -78,6 +78,8 @@ static const struct fetch_type probe_fetch_types[] = {
/* Special types */
__ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1,
"__data_loc char[]"),
+ __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1,
+ "__data_loc char[]"),
/* Basic types */
ASSIGN_FETCH_TYPE(u8, u8, 0),
ASSIGN_FETCH_TYPE(u16, u16, 0),
@@ -569,7 +571,8 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
goto fail;
/* Store operation */
- if (!strcmp(parg->type->name, "string")) {
+ if (!strcmp(parg->type->name, "string") ||
+ !strcmp(parg->type->name, "ustring")) {
if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_IMM &&
code->op != FETCH_OP_COMM) {
trace_probe_log_err(offset + (t ? (t - arg) : 0),
@@ -590,7 +593,11 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
goto fail;
}
}
- code->op = FETCH_OP_ST_STRING; /* In DEREF case, replace it */
+ /* If op == DEREF, replace it with STRING */
+ if (!strcmp(parg->type->name, "ustring"))
+ code->op = FETCH_OP_ST_USTRING;
+ else
+ code->op = FETCH_OP_ST_STRING;
code->size = parg->type->size;
parg->dynamic = true;
} else if (code->op == FETCH_OP_DEREF) {
@@ -618,7 +625,8 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
/* Loop(Array) operation */
if (parg->count) {
if (scode->op != FETCH_OP_ST_MEM &&
- scode->op != FETCH_OP_ST_STRING) {
+ scode->op != FETCH_OP_ST_STRING &&
+ scode->op != FETCH_OP_ST_USTRING) {
trace_probe_log_err(offset + (t ? (t - arg) : 0),
BAD_STRING);
ret = -EINVAL;
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index f9a8c632188b..c7546e7ff8e2 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -96,6 +96,7 @@ enum fetch_op {
FETCH_OP_ST_RAW, /* Raw: .size */
FETCH_OP_ST_MEM, /* Mem: .offset, .size */
FETCH_OP_ST_STRING, /* String: .offset, .size */
+ FETCH_OP_ST_USTRING, /* User String: .offset, .size */
// Stage 4 (modify) op
FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */
// Stage 5 (loop) op
diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h
index c30c61f12ddd..2e9e4dae8839 100644
--- a/kernel/trace/trace_probe_tmpl.h
+++ b/kernel/trace/trace_probe_tmpl.h
@@ -59,6 +59,9 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs,
static nokprobe_inline int fetch_store_strlen(unsigned long addr);
static nokprobe_inline int
fetch_store_string(unsigned long addr, void *dest, void *base);
+static nokprobe_inline int fetch_store_strlen_user(unsigned long addr);
+static nokprobe_inline int
+fetch_store_string_user(unsigned long addr, void *dest, void *base);
static nokprobe_inline int
probe_mem_read(void *dest, void *src, size_t size);
@@ -91,6 +94,10 @@ stage3:
ret = fetch_store_strlen(val + code->offset);
code++;
goto array;
+ } else if (code->op == FETCH_OP_ST_USTRING) {
+ ret += fetch_store_strlen_user(val + code->offset);
+ code++;
+ goto array;
} else
return -EILSEQ;
}
@@ -106,6 +113,10 @@ stage3:
loc = *(u32 *)dest;
ret = fetch_store_string(val + code->offset, dest, base);
break;
+ case FETCH_OP_ST_USTRING:
+ loc = *(u32 *)dest;
+ ret = fetch_store_string_user(val + code->offset, dest, base);
+ break;
default:
return -EILSEQ;
}
@@ -123,7 +134,8 @@ array:
total += ret;
if (++i < code->param) {
code = s3;
- if (s3->op != FETCH_OP_ST_STRING) {
+ if (s3->op != FETCH_OP_ST_STRING &&
+ s3->op != FETCH_OP_ST_USTRING) {
dest += s3->size;
val += s3->size;
goto stage3;
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index eb7e06b54741..852e998051f6 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -176,6 +176,12 @@ fetch_store_string(unsigned long addr, void *dest, void *base)
return ret;
}
+static nokprobe_inline int
+fetch_store_string_user(unsigned long addr, void *dest, void *base)
+{
+ return fetch_store_string(addr, dest, base);
+}
+
/* Return the length of string -- including null terminal byte */
static nokprobe_inline int
fetch_store_strlen(unsigned long addr)
@@ -191,6 +197,12 @@ fetch_store_strlen(unsigned long addr)
return (len > MAX_STRING_SIZE) ? 0 : len;
}
+static nokprobe_inline int
+fetch_store_strlen_user(unsigned long addr)
+{
+ return fetch_store_strlen(addr);
+}
+
static unsigned long translate_user_vaddr(unsigned long file_offset)
{
unsigned long base_addr;