Walk user/kernel stack in trace_entry rather than trace_return

nanshuaibo · Jan 18, 2022 · b1d8796 · b1d8796
1 parent d3475ad
commit b1d8796
Showing 1 changed file with 44 additions and 28 deletions.
diff --git a/tools/funcslower.py b/tools/funcslower.py
@@ -88,6 +88,13 @@
  u64 args[5];
 #endif
 #endif
+#ifdef USER_STACKS
+ int user_stack_id;
+#endif
+#ifdef KERNEL_STACKS
+ int kernel_stack_id;
+ u64 kernel_ip;
+#endif
 };
 
 struct data_t {
@@ -143,6 +150,40 @@
 #endif
 #endif
 
+#ifdef USER_STACKS
+ entry.user_stack_id = stacks.get_stackid(ctx, BPF_F_USER_STACK);
+#endif
+
+#ifdef KERNEL_STACKS
+ entry.kernel_stack_id = stacks.get_stackid(ctx, 0);
+
+ if (entry.kernel_stack_id >= 0) {
+ u64 ip = PT_REGS_IP(ctx);
+ u64 page_offset;
+
+ // if ip isn't sane, leave key ips as zero for later checking
+#if defined(CONFIG_X86_64) && defined(__PAGE_OFFSET_BASE)
+ // x64, 4.16, ..., 4.11, etc., but some earlier kernel didn't have it
+ page_offset = __PAGE_OFFSET_BASE;
+#elif defined(CONFIG_X86_64) && defined(__PAGE_OFFSET_BASE_L4)
+ // x64, 4.17, and later
+#if defined(CONFIG_DYNAMIC_MEMORY_LAYOUT) && defined(CONFIG_X86_5LEVEL)
+ page_offset = __PAGE_OFFSET_BASE_L5;
+#else
+ page_offset = __PAGE_OFFSET_BASE_L4;
+#endif
+#else
+ // earlier x86_64 kernels, e.g., 4.6, comes here
+ // arm64, s390, powerpc, x86_32
+ page_offset = PAGE_OFFSET;
+#endif
+
+ if (ip > page_offset) {
+ entry.kernel_ip = ip;
+ }
+ }
+#endif
+
  entryinfo.update(&tgid_pid, &entry);
 
  return 0;
@@ -172,37 +213,12 @@
  data.retval = PT_REGS_RC(ctx);
 
 #ifdef USER_STACKS
- data.user_stack_id = stacks.get_stackid(ctx, BPF_F_USER_STACK);
+ data.user_stack_id = entryp->user_stack_id;
 #endif
 
 #ifdef KERNEL_STACKS
- data.kernel_stack_id = stacks.get_stackid(ctx, 0);
-
- if (data.kernel_stack_id >= 0) {
- u64 ip = PT_REGS_IP(ctx);
- u64 page_offset;
-
- // if ip isn't sane, leave key ips as zero for later checking
-#if defined(CONFIG_X86_64) && defined(__PAGE_OFFSET_BASE)
- // x64, 4.16, ..., 4.11, etc., but some earlier kernel didn't have it
- page_offset = __PAGE_OFFSET_BASE;
-#elif defined(CONFIG_X86_64) && defined(__PAGE_OFFSET_BASE_L4)
- // x64, 4.17, and later
-#if defined(CONFIG_DYNAMIC_MEMORY_LAYOUT) && defined(CONFIG_X86_5LEVEL)
- page_offset = __PAGE_OFFSET_BASE_L5;
-#else
- page_offset = __PAGE_OFFSET_BASE_L4;
-#endif
-#else
- // earlier x86_64 kernels, e.g., 4.6, comes here
- // arm64, s390, powerpc, x86_32
- page_offset = PAGE_OFFSET;
-#endif
-
- if (ip > page_offset) {
- data.kernel_ip = ip;
- }
- }
+ data.kernel_stack_id = entryp->kernel_stack_id;
+ data.kernel_ip = entryp->kernel_ip;
 #endif
 
 #ifdef GRAB_ARGS