uprobe.patch

gistfile1.txt

commit 646676ced3ec352abcd348fd34509d470d59d5bb
Author: lijunlong <[email protected]>
Date:   Thu Jun 5 07:37:00 2025 +0800

    bugfix: buildid check failed because the Offset does not equal to the VirtAddr.
    
    $readelf -l -W envoy
    
    Elf file type is DYN (Position-Independent Executable file)
    Entry point 0x192e000
    There are 12 program headers, starting at offset 64
    Program Headers:
      Type           Offset   VirtAddr           PhysAddr           FileSiz  MemSiz   Flg Align
      PHDR           0x000040 0x0000000000000040 0x0000000000000040 0x0002a0 0x0002a0 R   0x8
      INTERP         0x0002e0 0x00000000000002e0 0x00000000000002e0 0x00001c 0x00001c R   0x1
          [Requesting program interpreter: /lib64/ld-linux-x86-64.so.2]
      LOAD           0x000000 0x0000000000000000 0x0000000000000000 0x192cdec 0x192cdec R   0x1000
      LOAD           0x192d000 0x000000000192e000 0x000000000192e000 0x2c95710 0x2c95710 R E 0x1000
      LOAD           0x45c2740 0x00000000045c4740 0x00000000045c4740 0x267830 0x2678c0 RW  0x1000
      LOAD           0x4829f70 0x000000000482cf70 0x000000000482cf70 0x0b6f70 0xc332b0 RW  0x1000
      TLS            0x45c2740 0x00000000045c4740 0x00000000045c4740 0x000110 0x0026e0 R   0x40
      DYNAMIC        0x48226b8 0x00000000048246b8 0x00000000048246b8 0x000200 0x000200 RW  0x8
      GNU_RELRO      0x45c2740 0x00000000045c4740 0x00000000045c4740 0x267830 0x2678c0 R   0x1
      GNU_EH_FRAME   0x110ae58 0x000000000110ae58 0x000000000110ae58 0x15c30c 0x15c30c R   0x4
      GNU_STACK      0x000000 0x0000000000000000 0x0000000000000000 0x000000 0x000000 RW  0
      NOTE           0x0002fc 0x00000000000002fc 0x00000000000002fc 0x000044 0x000044 R   0x4

diff --git a/dwflpp.h b/dwflpp.h
index d90ce9436..225c0a276 100644
--- a/dwflpp.h
+++ b/dwflpp.h
@@ -124,6 +124,12 @@ typedef std::vector<func_info> func_info_map_t;
 typedef std::vector<inline_instance_info> inline_instance_map_t;
 
 
+struct elf_hdr {
+  Dwarf_Addr file_offset;   // file offset
+  Dwarf_Addr vaddr_start;   // start of the virtual address
+  Dwarf_Addr vaddr_end;     // end of the virtual address
+};
+
 struct
 module_info
 {
@@ -139,6 +145,7 @@ module_info
   std::set<interned_string> inlined_funcs;
   std::set<interned_string> plt_funcs;
   std::set<std::pair<std::string,std::string> > marks; /* <provider,name> */
+  std::vector<struct elf_hdr> hdrs;
 
   void get_symtab();
   void update_symtab(cu_function_cache_t *funcs);
diff --git a/runtime/linux/task_finder2.c b/runtime/linux/task_finder2.c
index 9c2f5ad88..951720d21 100644
--- a/runtime/linux/task_finder2.c
+++ b/runtime/linux/task_finder2.c
@@ -784,6 +784,22 @@ __stp_find_file_based_vma(struct mm_struct *mm, unsigned long addr)
 	return vma;
 }
 
+static unsigned long
+__stp_find_elf_base_addr(struct mm_struct *mm, struct vm_area_struct *target_vma)
+{
+    unsigned long base_addr = target_vma->vm_start;
+    struct vm_area_struct *vma;
+
+    VMA_ITERATOR(vmi, mm, 0);
+    for_each_vma(vmi, vma) {
+        if (vma->vm_file == target_vma->vm_file || vma == target_vma) {
+            base_addr = vma->vm_start;
+            break;
+        }
+    }
+
+    return base_addr;
+}
 
 static void
 __stp_call_mmap_callbacks_with_addr(struct stap_task_finder_target *tgt,
@@ -798,6 +814,7 @@ __stp_call_mmap_callbacks_with_addr(struct stap_task_finder_target *tgt,
 	unsigned long length = 0;
 	unsigned long offset = 0;
 	unsigned long vm_flags = 0;
+	unsigned long base_addr = 0;
 
 	// __stp_call_mmap_callbacks_with_addr() is only called when
 	// tsk is current, so there isn't any danger of mm going
@@ -816,7 +833,9 @@ __stp_call_mmap_callbacks_with_addr(struct stap_task_finder_target *tgt,
 		// Cache information we need from the vma
 		addr = vma->vm_start;
 		length = vma->vm_end - vma->vm_start;
-		offset = (vma->vm_pgoff << PAGE_SHIFT);
+		base_addr = __stp_find_elf_base_addr(mm, vma);
+		//offset = (vma->vm_pgoff << PAGE_SHIFT);
+		offset = addr - base_addr;
 		vm_flags = vma->vm_flags;
 #ifdef STAPCONF_DPATH_PATH
 		dentry = vma->vm_file->f_path.dentry;
@@ -1268,6 +1287,8 @@ __stp_call_mmap_callbacks_for_task(struct stap_task_finder_target *tgt,
 	};
 	struct vma_cache_t *vma_cache = NULL;
 	struct vma_cache_t *vma_cache_p; 
+	struct file *mm_file = NULL;
+	unsigned long base_addr = 0;
 
 	// Call the mmap_callback for every vma associated with
 	// a file.
@@ -1331,9 +1352,15 @@ __stp_call_mmap_callbacks_for_task(struct stap_task_finder_target *tgt,
 			    mntget(vma_cache_p->f_vfsmnt);
 			    vma_cache_p->dentry = vma->vm_file->f_dentry;
 #endif
+			    if (mm_file == NULL || mm_file != vma->vm_file) {
+			        mm_file = vma->vm_file;
+			        base_addr = vma->vm_start;
+			    }
+
 			    vma_cache_p->addr = vma->vm_start;
 			    vma_cache_p->length = vma->vm_end - vma->vm_start;
-			    vma_cache_p->offset = (vma->vm_pgoff << PAGE_SHIFT);
+			    //vma_cache_p->offset = (vma->vm_pgoff << PAGE_SHIFT);
+			    vma_cache_p->offset = vma->vm_start - base_addr;
 			    vma_cache_p->vm_flags = vma->vm_flags;
 			    vma_cache_p++;
 			}
diff --git a/tapsets.cxx b/tapsets.cxx
index 01fec29e3..5cd893b7c 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -2664,6 +2664,30 @@ query_module (Dwfl_Module *mod,
             {
               mi->dwarf_status = info_absent;
             }
+
+          {
+            Dwarf_Addr load_addr;
+            Elf* elf = dwfl_module_getelf (mod, &load_addr);
+
+            // Get the load address, readelf -l -W elf | grep LOAD
+            for (int i = 0; ; i++)
+              {
+                GElf_Phdr mem;
+                GElf_Phdr *phdr;
+                phdr = gelf_getphdr (elf, i, &mem);
+                if (phdr == NULL)
+                  break;
+
+                if (phdr->p_type == PT_LOAD)
+                  {
+                    struct elf_hdr hdr;
+                    hdr.file_offset = phdr->p_offset;
+                    hdr.vaddr_start = phdr->p_vaddr;
+                    hdr.vaddr_end = phdr->p_vaddr + phdr->p_memsz;
+                    mi->hdrs.push_back(hdr);
+                  }
+              }
+          }
         }
       // OK, enough of that module_info caching business.
 
@@ -5610,9 +5634,19 @@ dwarf_derived_probe::dwarf_derived_probe(interned_string funcname,
       // inode-uprobes needs an offset rather than an absolute VM address.
       // ditto for userspace runtimes (dyninst)
       if ((kernel_supports_inode_uprobes(q.dw.sess) || q.dw.sess.runtime_usermode_p()) &&
-          section == ".absolute" && addr == dwfl_addr &&
-          addr >= q.dw.module_start && addr < q.dw.module_end)
-        this->addr = addr - q.dw.module_start;
+          section == ".absolute" && addr == dwfl_addr)
+        {
+          // An ELF file maybe loaded into multiple non-contiguous memory addresses,
+          for (auto it = q.dw.mod_info->hdrs.begin();
+               it != q.dw.mod_info->hdrs.end(); ++it)
+            {
+              if (it->vaddr_start <= addr && addr < it->vaddr_end)
+              {
+                this->addr = addr - it->vaddr_start + it->file_offset;
+                break;
+              }
+            }
+        }
     }
   else
     {