summaryrefslogtreecommitdiff
path: root/kernel/trace/trace_uprobe.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/trace/trace_uprobe.c')
-rw-r--r--kernel/trace/trace_uprobe.c255
1 files changed, 142 insertions, 113 deletions
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index e696667da29a..31ea48eceda1 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -15,6 +15,7 @@
#include <linux/rculist.h>
#include "trace_probe.h"
+#include "trace_probe_tmpl.h"
#define UPROBE_EVENT_SYSTEM "uprobes"
@@ -47,6 +48,7 @@ struct trace_uprobe {
struct inode *inode;
char *filename;
unsigned long offset;
+ unsigned long ref_ctr_offset;
unsigned long nhit;
struct trace_probe tp;
};
@@ -98,74 +100,52 @@ static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
/*
* Uprobes-specific fetch functions
*/
-#define DEFINE_FETCH_stack(type) \
-static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
- void *offset, void *dest) \
-{ \
- *(type *)dest = (type)get_user_stack_nth(regs, \
- ((unsigned long)offset)); \
-}
-DEFINE_BASIC_FETCH_FUNCS(stack)
-/* No string on the stack entry */
-#define fetch_stack_string NULL
-#define fetch_stack_string_size NULL
-
-#define DEFINE_FETCH_memory(type) \
-static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \
- void *addr, void *dest) \
-{ \
- type retval; \
- void __user *vaddr = (void __force __user *) addr; \
- \
- if (copy_from_user(&retval, vaddr, sizeof(type))) \
- *(type *)dest = 0; \
- else \
- *(type *) dest = retval; \
+static nokprobe_inline int
+probe_mem_read(void *dest, void *src, size_t size)
+{
+ void __user *vaddr = (void __force __user *)src;
+
+ return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
}
-DEFINE_BASIC_FETCH_FUNCS(memory)
/*
* Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
* length and relative data location.
*/
-static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
- void *addr, void *dest)
+static nokprobe_inline int
+fetch_store_string(unsigned long addr, void *dest, void *base)
{
long ret;
- u32 rloc = *(u32 *)dest;
- int maxlen = get_rloc_len(rloc);
- u8 *dst = get_rloc_data(dest);
+ u32 loc = *(u32 *)dest;
+ int maxlen = get_loc_len(loc);
+ u8 *dst = get_loc_data(dest, base);
void __user *src = (void __force __user *) addr;
- if (!maxlen)
- return;
+ if (unlikely(!maxlen))
+ return -ENOMEM;
ret = strncpy_from_user(dst, src, maxlen);
- if (ret == maxlen)
- dst[--ret] = '\0';
-
- if (ret < 0) { /* Failed to fetch string */
- ((u8 *)get_rloc_data(dest))[0] = '\0';
- *(u32 *)dest = make_data_rloc(0, get_rloc_offs(rloc));
- } else {
- *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(rloc));
+ if (ret >= 0) {
+ if (ret == maxlen)
+ dst[ret - 1] = '\0';
+ *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
}
+
+ return ret;
}
-static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
- void *addr, void *dest)
+/* Return the length of string -- including null terminal byte */
+static nokprobe_inline int
+fetch_store_strlen(unsigned long addr)
{
int len;
void __user *vaddr = (void __force __user *) addr;
len = strnlen_user(vaddr, MAX_STRING_SIZE);
- if (len == 0 || len > MAX_STRING_SIZE) /* Failed to check length */
- *(u32 *)dest = 0;
- else
- *(u32 *)dest = len;
+ return (len > MAX_STRING_SIZE) ? 0 : len;
}
-static unsigned long translate_user_vaddr(void *file_offset)
+static unsigned long translate_user_vaddr(unsigned long file_offset)
{
unsigned long base_addr;
struct uprobe_dispatch_data *udd;
@@ -173,44 +153,44 @@ static unsigned long translate_user_vaddr(void *file_offset)
udd = (void *) current->utask->vaddr;
base_addr = udd->bp_addr - udd->tu->offset;
- return base_addr + (unsigned long)file_offset;
+ return base_addr + file_offset;
}
-#define DEFINE_FETCH_file_offset(type) \
-static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs, \
- void *offset, void *dest)\
-{ \
- void *vaddr = (void *)translate_user_vaddr(offset); \
- \
- FETCH_FUNC_NAME(memory, type)(regs, vaddr, dest); \
+/* Note that we don't verify it, since the code does not come from user space */
+static int
+process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
+ void *base)
+{
+ unsigned long val;
+
+ /* 1st stage: get value from context */
+ switch (code->op) {
+ case FETCH_OP_REG:
+ val = regs_get_register(regs, code->param);
+ break;
+ case FETCH_OP_STACK:
+ val = get_user_stack_nth(regs, code->param);
+ break;
+ case FETCH_OP_STACKP:
+ val = user_stack_pointer(regs);
+ break;
+ case FETCH_OP_RETVAL:
+ val = regs_return_value(regs);
+ break;
+ case FETCH_OP_IMM:
+ val = code->immediate;
+ break;
+ case FETCH_OP_FOFFS:
+ val = translate_user_vaddr(code->immediate);
+ break;
+ default:
+ return -EILSEQ;
+ }
+ code++;
+
+ return process_fetch_insn_bottom(code, val, dest, base);
}
-DEFINE_BASIC_FETCH_FUNCS(file_offset)
-DEFINE_FETCH_file_offset(string)
-DEFINE_FETCH_file_offset(string_size)
-
-/* Fetch type information table */
-static const struct fetch_type uprobes_fetch_type_table[] = {
- /* Special types */
- [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
- sizeof(u32), 1, "__data_loc char[]"),
- [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
- string_size, sizeof(u32), 0, "u32"),
- /* Basic types */
- ASSIGN_FETCH_TYPE(u8, u8, 0),
- ASSIGN_FETCH_TYPE(u16, u16, 0),
- ASSIGN_FETCH_TYPE(u32, u32, 0),
- ASSIGN_FETCH_TYPE(u64, u64, 0),
- ASSIGN_FETCH_TYPE(s8, u8, 1),
- ASSIGN_FETCH_TYPE(s16, u16, 1),
- ASSIGN_FETCH_TYPE(s32, u32, 1),
- ASSIGN_FETCH_TYPE(s64, u64, 1),
- ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
- ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
- ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
- ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
-
- ASSIGN_FETCH_TYPE_END
-};
+NOKPROBE_SYMBOL(process_fetch_insn)
static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
{
@@ -311,6 +291,35 @@ static int unregister_trace_uprobe(struct trace_uprobe *tu)
return 0;
}
+/*
+ * Uprobe with multiple reference counter is not allowed. i.e.
+ * If inode and offset matches, reference counter offset *must*
+ * match as well. Though, there is one exception: If user is
+ * replacing old trace_uprobe with new one(same group/event),
+ * then we allow same uprobe with new reference counter as far
+ * as the new one does not conflict with any other existing
+ * ones.
+ */
+static struct trace_uprobe *find_old_trace_uprobe(struct trace_uprobe *new)
+{
+ struct trace_uprobe *tmp, *old = NULL;
+ struct inode *new_inode = d_real_inode(new->path.dentry);
+
+ old = find_probe_event(trace_event_name(&new->tp.call),
+ new->tp.call.class->system);
+
+ list_for_each_entry(tmp, &uprobe_list, list) {
+ if ((old ? old != tmp : true) &&
+ new_inode == d_real_inode(tmp->path.dentry) &&
+ new->offset == tmp->offset &&
+ new->ref_ctr_offset != tmp->ref_ctr_offset) {
+ pr_warn("Reference counter offset mismatch.");
+ return ERR_PTR(-EINVAL);
+ }
+ }
+ return old;
+}
+
/* Register a trace_uprobe and probe_event */
static int register_trace_uprobe(struct trace_uprobe *tu)
{
@@ -320,8 +329,12 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
mutex_lock(&uprobe_lock);
/* register as an event */
- old_tu = find_probe_event(trace_event_name(&tu->tp.call),
- tu->tp.call.class->system);
+ old_tu = find_old_trace_uprobe(tu);
+ if (IS_ERR(old_tu)) {
+ ret = PTR_ERR(old_tu);
+ goto end;
+ }
+
if (old_tu) {
/* delete old event */
ret = unregister_trace_uprobe(old_tu);
@@ -352,10 +365,10 @@ end:
static int create_trace_uprobe(int argc, char **argv)
{
struct trace_uprobe *tu;
- char *arg, *event, *group, *filename;
+ char *arg, *event, *group, *filename, *rctr, *rctr_end;
char buf[MAX_EVENT_NAME_LEN];
struct path path;
- unsigned long offset;
+ unsigned long offset, ref_ctr_offset;
bool is_delete, is_return;
int i, ret;
@@ -364,6 +377,7 @@ static int create_trace_uprobe(int argc, char **argv)
is_return = false;
event = NULL;
group = NULL;
+ ref_ctr_offset = 0;
/* argc must be >= 1 */
if (argv[0][0] == '-')
@@ -438,6 +452,26 @@ static int create_trace_uprobe(int argc, char **argv)
goto fail_address_parse;
}
+ /* Parse reference counter offset if specified. */
+ rctr = strchr(arg, '(');
+ if (rctr) {
+ rctr_end = strchr(rctr, ')');
+ if (rctr > rctr_end || *(rctr_end + 1) != 0) {
+ ret = -EINVAL;
+ pr_info("Invalid reference counter offset.\n");
+ goto fail_address_parse;
+ }
+
+ *rctr++ = '\0';
+ *rctr_end = '\0';
+ ret = kstrtoul(rctr, 0, &ref_ctr_offset);
+ if (ret) {
+ pr_info("Invalid reference counter offset.\n");
+ goto fail_address_parse;
+ }
+ }
+
+ /* Parse uprobe offset. */
ret = kstrtoul(arg, 0, &offset);
if (ret)
goto fail_address_parse;
@@ -472,6 +506,7 @@ static int create_trace_uprobe(int argc, char **argv)
goto fail_address_parse;
}
tu->offset = offset;
+ tu->ref_ctr_offset = ref_ctr_offset;
tu->path = path;
tu->filename = kstrdup(filename, GFP_KERNEL);
@@ -522,8 +557,7 @@ static int create_trace_uprobe(int argc, char **argv)
/* Parse fetch argument */
ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,
- is_return, false,
- uprobes_fetch_type_table);
+ is_return ? TPARG_FL_RETURN : 0);
if (ret) {
pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
goto error;
@@ -590,6 +624,9 @@ static int probes_seq_show(struct seq_file *m, void *v)
trace_event_name(&tu->tp.call), tu->filename,
(int)(sizeof(void *) * 2), tu->offset);
+ if (tu->ref_ctr_offset)
+ seq_printf(m, "(0x%lx)", tu->ref_ctr_offset);
+
for (i = 0; i < tu->tp.nr_args; i++)
seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
@@ -833,7 +870,6 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e
struct trace_seq *s = &iter->seq;
struct trace_uprobe *tu;
u8 *data;
- int i;
entry = (struct uprobe_trace_entry_head *)iter->ent;
tu = container_of(event, struct trace_uprobe, tp.call.event);
@@ -850,12 +886,8 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e
data = DATAOF_TRACE_ENTRY(entry, false);
}
- for (i = 0; i < tu->tp.nr_args; i++) {
- struct probe_arg *parg = &tu->tp.args[i];
-
- if (!parg->type->print(s, parg->name, data + parg->offset, entry))
- goto out;
- }
+ if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
+ goto out;
trace_seq_putc(s, '\n');
@@ -905,7 +937,13 @@ probe_event_enable(struct trace_uprobe *tu, struct trace_event_file *file,
tu->consumer.filter = filter;
tu->inode = d_real_inode(tu->path.dentry);
- ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
+ if (tu->ref_ctr_offset) {
+ ret = uprobe_register_refctr(tu->inode, tu->offset,
+ tu->ref_ctr_offset, &tu->consumer);
+ } else {
+ ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
+ }
+
if (ret)
goto err_buffer;
@@ -958,7 +996,7 @@ probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)
static int uprobe_event_define_fields(struct trace_event_call *event_call)
{
- int ret, i, size;
+ int ret, size;
struct uprobe_trace_entry_head field;
struct trace_uprobe *tu = event_call->data;
@@ -970,19 +1008,8 @@ static int uprobe_event_define_fields(struct trace_event_call *event_call)
DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
size = SIZEOF_TRACE_ENTRY(false);
}
- /* Set argument names as fields */
- for (i = 0; i < tu->tp.nr_args; i++) {
- struct probe_arg *parg = &tu->tp.args[i];
-
- ret = trace_define_field(event_call, parg->type->fmttype,
- parg->name, size + parg->offset,
- parg->type->size, parg->type->is_signed,
- FILTER_OTHER);
- if (ret)
- return ret;
- }
- return 0;
+ return traceprobe_define_arg_fields(event_call, size, &tu->tp);
}
#ifdef CONFIG_PERF_EVENTS
@@ -1233,7 +1260,7 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
ucb = uprobe_buffer_get();
- store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
+ store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
if (tu->tp.flags & TP_FLAG_TRACE)
ret |= uprobe_trace_func(tu, regs, ucb, dsize);
@@ -1268,7 +1295,7 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con,
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
ucb = uprobe_buffer_get();
- store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
+ store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
if (tu->tp.flags & TP_FLAG_TRACE)
uretprobe_trace_func(tu, func, regs, ucb, dsize);
@@ -1304,7 +1331,7 @@ static int register_uprobe_event(struct trace_uprobe *tu)
init_trace_event_call(tu, call);
- if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0)
+ if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0)
return -ENOMEM;
ret = register_trace_event(&call->event);
@@ -1340,7 +1367,8 @@ static int unregister_uprobe_event(struct trace_uprobe *tu)
#ifdef CONFIG_PERF_EVENTS
struct trace_event_call *
-create_local_trace_uprobe(char *name, unsigned long offs, bool is_return)
+create_local_trace_uprobe(char *name, unsigned long offs,
+ unsigned long ref_ctr_offset, bool is_return)
{
struct trace_uprobe *tu;
struct path path;
@@ -1372,10 +1400,11 @@ create_local_trace_uprobe(char *name, unsigned long offs, bool is_return)
tu->offset = offs;
tu->path = path;
+ tu->ref_ctr_offset = ref_ctr_offset;
tu->filename = kstrdup(name, GFP_KERNEL);
init_trace_event_call(tu, &tu->tp.call);
- if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
+ if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
ret = -ENOMEM;
goto error;
}