[PATCH 2/4] kernel/trace/kprobe: Use new APIs to process kprobe arguments

From: Song Chen
Date: Wed Nov 16 2022 - 07:22:29 EST


Trace probe introduces new APIs to process probe arguments, so
kprobe shall remove old implementations and turn to those new
APIs.

Signed-off-by: Song Chen <chensong_2000@xxxxxx>
---
kernel/trace/trace_kprobe.c | 125 +++---------------------------------
1 file changed, 10 insertions(+), 115 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 5a75b039e586..d734602f2898 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -19,8 +19,6 @@
#include "trace_dynevent.h"
#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
@@ -1218,109 +1216,6 @@ static const struct file_operations kprobe_profile_ops = {
.release = seq_release,
};

-/* Kprobe specific fetch functions */
-
-/* Return the length of string -- including null terminal byte */
-static nokprobe_inline int
-fetch_store_strlen_user(unsigned long addr)
-{
- 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)
-{
- return kern_fetch_store_strlen(addr);
-}
-
-/*
- * 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)
-{
- return kern_fetch_store_string_user(addr, dest, base);
-}
-
-/*
- * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
- * length and relative data location.
- */
-static nokprobe_inline int
-fetch_store_string(unsigned long addr, void *dest, void *base)
-{
- return kern_fetch_store_string(addr, dest, base);
-}
-
-static nokprobe_inline int
-probe_mem_read_user(void *dest, void *src, size_t size)
-{
- const void __user *uaddr = (__force const void __user *)src;
-
- return copy_from_user_nofault(dest, uaddr, size);
-}
-
-static nokprobe_inline int
-probe_mem_read(void *dest, void *src, size_t size)
-{
-#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
- if ((unsigned long)src < TASK_SIZE)
- return probe_mem_read_user(dest, src, size);
-#endif
- return copy_from_kernel_nofault(dest, src, size);
-}
-
-/* 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;
-
-retry:
- /* 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 = regs_get_kernel_stack_nth(regs, code->param);
- break;
- case FETCH_OP_STACKP:
- val = kernel_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 = (unsigned long)current->comm;
- break;
- case FETCH_OP_DATA:
- val = (unsigned long)code->data;
- break;
-#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
- case FETCH_OP_ARG:
- val = regs_get_kernel_argument(regs, code->param);
- break;
-#endif
- case FETCH_NOP_SYMBOL: /* Ignore a place holder */
- code++;
- goto retry;
- default:
- return -EILSEQ;
- }
- code++;
-
- return process_fetch_insn_bottom(code, val, dest, base);
-}
-NOKPROBE_SYMBOL(process_fetch_insn)
-
/* Kprobe handler */
static nokprobe_inline void
__kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
@@ -1336,7 +1231,7 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
if (trace_trigger_soft_disabled(trace_file))
return;

- dsize = __get_data_size(&tk->tp, regs);
+ dsize = trace_probe_get_data_size(&tk->tp, regs);

entry = trace_event_buffer_reserve(&fbuffer, trace_file,
sizeof(*entry) + tk->tp.size + dsize);
@@ -1346,7 +1241,7 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
fbuffer.regs = regs;
entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
entry->ip = (unsigned long)tk->rp.kp.addr;
- store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
+ trace_probe_store_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);

trace_event_buffer_commit(&fbuffer);
}
@@ -1377,7 +1272,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
if (trace_trigger_soft_disabled(trace_file))
return;

- dsize = __get_data_size(&tk->tp, regs);
+ dsize = trace_probe_get_data_size(&tk->tp, regs);

entry = trace_event_buffer_reserve(&fbuffer, trace_file,
sizeof(*entry) + tk->tp.size + dsize);
@@ -1388,7 +1283,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
entry->func = (unsigned long)tk->rp.kp.addr;
entry->ret_ip = get_kretprobe_retaddr(ri);
- store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
+ trace_probe_store_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);

trace_event_buffer_commit(&fbuffer);
}
@@ -1426,7 +1321,7 @@ print_kprobe_event(struct trace_iterator *iter, int flags,

trace_seq_putc(s, ')');

- if (print_probe_args(s, tp->args, tp->nr_args,
+ if (trace_probe_print_args(s, tp->args, tp->nr_args,
(u8 *)&field[1], field) < 0)
goto out;

@@ -1461,7 +1356,7 @@ print_kretprobe_event(struct trace_iterator *iter, int flags,

trace_seq_putc(s, ')');

- if (print_probe_args(s, tp->args, tp->nr_args,
+ if (trace_probe_print_args(s, tp->args, tp->nr_args,
(u8 *)&field[1], field) < 0)
goto out;

@@ -1536,7 +1431,7 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
if (hlist_empty(head))
return 0;

- dsize = __get_data_size(&tk->tp, regs);
+ dsize = trace_probe_get_data_size(&tk->tp, regs);
__size = sizeof(*entry) + tk->tp.size + dsize;
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
@@ -1547,7 +1442,7 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)

entry->ip = (unsigned long)tk->rp.kp.addr;
memset(&entry[1], 0, dsize);
- store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
+ trace_probe_store_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
head, NULL);
return 0;
@@ -1572,7 +1467,7 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
if (hlist_empty(head))
return;

- dsize = __get_data_size(&tk->tp, regs);
+ dsize = trace_probe_get_data_size(&tk->tp, regs);
__size = sizeof(*entry) + tk->tp.size + dsize;
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
@@ -1583,7 +1478,7 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,

entry->func = (unsigned long)tk->rp.kp.addr;
entry->ret_ip = get_kretprobe_retaddr(ri);
- store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
+ trace_probe_store_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
head, NULL);
}
--
2.25.1