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Subject[PATCH 4/4] kernel/trace/uprobe: Use new APIs to process uprobe arguments
Date
Trace probe introduces new APIs to process probe arguments, so
eprobe shall remove old implementations and turn to those new
APIs.

Signed-off-by: Song Chen <chensong_2000@189.cn>
---
kernel/trace/trace_probe.c | 5 +
kernel/trace/trace_probe.h | 6 ++
kernel/trace/trace_probe_user.h | 13 +++
kernel/trace/trace_uprobe.c | 177 ++------------------------------
4 files changed, 31 insertions(+), 170 deletions(-)

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 303f057bd2f7..56097d241290 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -1443,6 +1443,11 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
case FETCH_OP_TP_ARG:
val = get_event_field(code, rec);
break;
+#ifdef CONFIG_UPROBES
+ case FETCH_OP_FOFFS:
+ val = translate_user_vaddr(code->immediate);
+ break;
+#endif
default:
return -EILSEQ;
}
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 4f044047b748..918466087583 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -223,6 +223,12 @@ struct probe_arg {
const struct fetch_type *type; /* Type of this argument */
};

+struct uprobe_dispatch_data {
+ struct trace_uprobe *tu;
+ unsigned long bp_addr;
+ unsigned long offset;
+};
+
struct trace_uprobe_filter {
rwlock_t rwlock;
int nr_systemwide;
diff --git a/kernel/trace/trace_probe_user.h b/kernel/trace/trace_probe_user.h
index 2104ccb44d56..5a69b9074f3c 100644
--- a/kernel/trace/trace_probe_user.h
+++ b/kernel/trace/trace_probe_user.h
@@ -92,4 +92,17 @@ static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
return ret;
}

+#ifdef CONFIG_UPROBES
+static unsigned long translate_user_vaddr(unsigned long file_offset)
+{
+ unsigned long base_addr;
+ struct uprobe_dispatch_data *udd;
+
+ udd = (void *) current->utask->vaddr;
+
+ base_addr = udd->bp_addr - udd->offset;
+ return base_addr + file_offset;
+}
+#endif
+
#endif /* __TRACE_PROBE_USER_H_ */
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index fb58e86dd117..abce09295f05 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -20,7 +20,6 @@

#include "trace_dynevent.h"
#include "trace_probe.h"
-#include "trace_probe_tmpl.h"

#define UPROBE_EVENT_SYSTEM "uprobes"

@@ -88,174 +87,10 @@ static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
static int register_uprobe_event(struct trace_uprobe *tu);
static int unregister_uprobe_event(struct trace_uprobe *tu);

-struct uprobe_dispatch_data {
- struct trace_uprobe *tu;
- unsigned long bp_addr;
-};
-
static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
static int uretprobe_dispatcher(struct uprobe_consumer *con,
unsigned long func, struct pt_regs *regs);

-#ifdef CONFIG_STACK_GROWSUP
-static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
-{
- return addr - (n * sizeof(long));
-}
-#else
-static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
-{
- return addr + (n * sizeof(long));
-}
-#endif
-
-static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
-{
- unsigned long ret;
- unsigned long addr = user_stack_pointer(regs);
-
- addr = adjust_stack_addr(addr, n);
-
- if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
- return 0;
-
- return ret;
-}
-
-/*
- * Uprobes-specific fetch functions
- */
-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;
-}
-
-static nokprobe_inline int
-probe_mem_read_user(void *dest, void *src, size_t size)
-{
- return probe_mem_read(dest, src, size);
-}
-
-/*
- * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
- * length and relative data location.
- */
-static nokprobe_inline int
-fetch_store_string(unsigned long addr, void *dest, void *base)
-{
- long ret;
- 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 (unlikely(!maxlen))
- return -ENOMEM;
-
- if (addr == FETCH_TOKEN_COMM)
- ret = strlcpy(dst, current->comm, maxlen);
- else
- ret = strncpy_from_user(dst, src, maxlen);
- if (ret >= 0) {
- if (ret == maxlen)
- dst[ret - 1] = '\0';
- else
- /*
- * Include the terminating null byte. In this case it
- * was copied by strncpy_from_user but not accounted
- * for in ret.
- */
- ret++;
- *(u32 *)dest = make_data_loc(ret, (void *)dst - 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)
-{
- int len;
- void __user *vaddr = (void __force __user *) addr;
-
- if (addr == FETCH_TOKEN_COMM)
- len = strlen(current->comm) + 1;
- else
- len = strnlen_user(vaddr, MAX_STRING_SIZE);
-
- 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;
- struct uprobe_dispatch_data *udd;
-
- udd = (void *) current->utask->vaddr;
-
- base_addr = udd->bp_addr - udd->tu->offset;
- return base_addr + file_offset;
-}
-
-/* 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, void *rec, void *dest,
- void *base)
-{
- struct pt_regs *regs = rec;
- 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_COMM:
- val = FETCH_TOKEN_COMM;
- break;
- case FETCH_OP_DATA:
- val = (unsigned long)code->data;
- 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);
-}
-NOKPROBE_SYMBOL(process_fetch_insn)
-
static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
{
rwlock_init(&filter->rwlock);
@@ -1041,7 +876,7 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e
data = DATAOF_TRACE_ENTRY(entry, false);
}

- if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
+ if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
goto out;

trace_seq_putc(s, '\n');
@@ -1485,6 +1320,7 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
tu->nhit++;

udd.tu = tu;
+ udd.offset = tu->offset;
udd.bp_addr = instruction_pointer(regs);

current->utask->vaddr = (unsigned long) &udd;
@@ -1492,11 +1328,11 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
if (WARN_ON_ONCE(!uprobe_cpu_buffer))
return 0;

- dsize = __get_data_size(&tu->tp, regs);
+ dsize = trace_probe_get_data_size(&tu->tp, regs);
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));

ucb = uprobe_buffer_get();
- store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
+ trace_probe_store_args(ucb->buf, &tu->tp, regs, esize, dsize);

if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
ret |= uprobe_trace_func(tu, regs, ucb, dsize);
@@ -1520,6 +1356,7 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con,
tu = container_of(con, struct trace_uprobe, consumer);

udd.tu = tu;
+ udd.offset = tu->offset;
udd.bp_addr = func;

current->utask->vaddr = (unsigned long) &udd;
@@ -1527,11 +1364,11 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con,
if (WARN_ON_ONCE(!uprobe_cpu_buffer))
return 0;

- dsize = __get_data_size(&tu->tp, regs);
+ dsize = trace_probe_get_data_size(&tu->tp, regs);
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));

ucb = uprobe_buffer_get();
- store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
+ trace_probe_store_args(ucb->buf, &tu->tp, regs, esize, dsize);

if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
uretprobe_trace_func(tu, func, regs, ucb, dsize);
--
2.25.1
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