From d4fdd69c48c02d33dd5fc6f256c5ea3c43178fe6 Mon Sep 17 00:00:00 2001
From: kamil <kamkow256@gmail.com>
Date: Wed, 12 Mar 2025 11:37:23 +0100
Subject: [PATCH] Get breakpoint filename and line number from DWARF

---
 debugus.c         |  9 +++++----
 libelfin_wrap.cpp | 34 ++++++++++++++++++++++++----------
 libelfin_wrap.h   |  7 +++++--
 3 files changed, 34 insertions(+), 16 deletions(-)

diff --git a/debugus.c b/debugus.c
index dcc60d3..ee26696 100644
--- a/debugus.c
+++ b/debugus.c
@@ -152,6 +152,7 @@ typedef struct {
     HashTable brks;
     uintptr_t program_load_offset;
     HashTable js_descs;
+    PLibelfinBinding plibelfin;
 } Dbg;
 
 siginfo_t dbg_get_siginfo(Dbg *dbg)
@@ -178,10 +179,9 @@ void dbg_handle_sigtrap(Dbg *dbg, siginfo_t info)
         case SI_KERNEL:
         case TRAP_BRKPT:
             dbg_set_rip(dbg, dbg_get_rip(dbg) - 1);
-            ai = libelfin_wrap_info_from_rip(dbg_get_rip(dbg));
+            ai = libelfin_wrap_info_from_rip(dbg->plibelfin, dbg_get_rip(dbg) - (uint64_t)dbg->program_load_offset);
             if (ai != NULL) {
-                LOG_INF("Hit breakpoint at 0x%"PRIxPTR", %s:%zu\n", dbg_get_rip(dbg),
-                        ai->file, (size_t)ai->line);
+                LOG_INF("Hit breakpoint at 0x%"PRIxPTR", %s:%zu\n", dbg_get_rip(dbg), ai->file, (size_t)ai->line);
                 libelfin_wrap_free_info(ai);
             } else {
                 LOG_INF("Hit breakpoint at 0x%"PRIxPTR"\n", dbg_get_rip(dbg));
@@ -538,7 +538,7 @@ void dbg_libelfin_wrap_init(Dbg *dbg)
         return;
     }
 
-    libelfin_wrap_init(fileno(bin));
+    dbg->plibelfin = libelfin_wrap_get_binding(fileno(bin));
 
     fclose(bin);
 }
@@ -561,6 +561,7 @@ void dbg_deinit(Dbg *dbg)
     js_freestate(dbg->js);
     hashtable_deinit(&dbg->brks);
     hashtable_deinit(&dbg->js_descs);
+    libelfin_wrap_free_binding(dbg->plibelfin);
 }
 
 void dbg_loop(Dbg *dbg)
diff --git a/libelfin_wrap.cpp b/libelfin_wrap.cpp
index 3d6682a..6048b07 100644
--- a/libelfin_wrap.cpp
+++ b/libelfin_wrap.cpp
@@ -1,25 +1,40 @@
+#include <inttypes.h>
 #include <libelfin/dwarf/dwarf++.hh>
 #include <libelfin/elf/elf++.hh>
 
 #include "libelfin_wrap.h"
 
-static elf::elf gelf;
-static dwarf::dwarf gdwarf;
-
-DEBUGUS_EXTERNC void libelfin_wrap_init(int fd)
+class LibelfinBinding
 {
-    gelf = elf::elf{elf::create_mmap_loader(fd)};
-    gdwarf = dwarf::dwarf{dwarf::elf::create_loader(gelf)};
+    public:
+        LibelfinBinding(int fd)
+            : elf(elf::create_mmap_loader(fd)),
+              dwarf(dwarf::elf::create_loader(this->elf))
+        {
+        }
+
+        elf::elf elf;
+        dwarf::dwarf dwarf;
+};
+
+DEBUGUS_EXTERNC PLibelfinBinding libelfin_wrap_get_binding(int fd)
+{
+    return (PLibelfinBinding)new LibelfinBinding(fd);
 }
 
-DEBUGUS_EXTERNC AddrInfo *libelfin_wrap_info_from_rip(uint64_t rip)
+DEBUGUS_EXTERNC void libelfin_wrap_free_binding(PLibelfinBinding pbind)
 {
-    for (auto &cu : gdwarf.compilation_units()) {
+    delete (LibelfinBinding *)pbind;
+}
+
+DEBUGUS_EXTERNC AddrInfo *libelfin_wrap_info_from_rip(PLibelfinBinding pbind, uint64_t rip)
+{
+    LibelfinBinding *bind = (LibelfinBinding *)pbind;
+    for (auto &cu : bind->dwarf.compilation_units()) {
         if (die_pc_range(cu.root()).contains(rip)) {
             auto &lt = cu.get_line_table();
             auto it = lt.find_address(rip);
             if (it == lt.end()) {
-                printf("ADDR NOT FOUND\n");
                 return NULL;
             } else {
                 AddrInfo *ai = (AddrInfo *)malloc(sizeof(*ai));
@@ -31,7 +46,6 @@ DEBUGUS_EXTERNC AddrInfo *libelfin_wrap_info_from_rip(uint64_t rip)
             }
         }
     }
-    printf("NO CUS\n");
     return NULL;
 }
 
diff --git a/libelfin_wrap.h b/libelfin_wrap.h
index dc2d05b..4715021 100644
--- a/libelfin_wrap.h
+++ b/libelfin_wrap.h
@@ -18,8 +18,11 @@ typedef struct {
     uint64_t addr;
 } AddrInfo;
 
-DEBUGUS_EXTERNC void libelfin_wrap_init(int fd);
-DEBUGUS_EXTERNC AddrInfo *libelfin_wrap_info_from_rip(uint64_t rip);
+typedef void * PLibelfinBinding;
+
+DEBUGUS_EXTERNC PLibelfinBinding libelfin_wrap_get_binding(int fd);
+DEBUGUS_EXTERNC void libelfin_wrap_free_binding(PLibelfinBinding pbind);
+DEBUGUS_EXTERNC AddrInfo *libelfin_wrap_info_from_rip(PLibelfinBinding pbind, uint64_t rip);
 DEBUGUS_EXTERNC void libelfin_wrap_free_info(AddrInfo *ai);
 
 #endif // LIBELFIN_WRAP_H_