From 319e1b85d278bad90caeb5b13c41a0f4ca81cb00 Mon Sep 17 00:00:00 2001
From: Yasumasa Suenaga <yasuenag@gmail.com>
Date: Sun, 19 Apr 2026 13:42:26 +0900
Subject: [PATCH 1/7] Use lib->base directly

---
 src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp      | 2 +-
 src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.c | 1 -
 src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.h | 1 -
 3 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp b/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp
index 28eb92a285f2e..8ce0046fdb732 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp
@@ -334,7 +334,7 @@ bool DwarfParser::process_dwarf(const uintptr_t pc) {
     uint32_t id = *(reinterpret_cast<uint32_t *>(_buf));
     _buf += 4;
     if (id != 0) { // FDE
-      uintptr_t pc_begin = get_decoded_value() + _lib->eh_frame.library_base_addr;
+      uintptr_t pc_begin = get_decoded_value() + _lib->base;
       uintptr_t pc_end = pc_begin + get_pc_range();
 
       if ((pc >= pc_begin) && (pc < pc_end)) {
diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.c b/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.c
index 815902045cff8..52d2ad5f404d0 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.c
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.c
@@ -231,7 +231,6 @@ bool read_eh_frame(struct ps_prochandle* ph, lib_info* lib) {
 
   for (cnt = 0, sh = shbuf; cnt < ehdr.e_shnum; cnt++, sh++) {
     if (strcmp(".eh_frame", sh->sh_name + strtab) == 0) {
-      lib->eh_frame.library_base_addr = lib->base;
       lib->eh_frame.v_addr = sh->sh_addr;
       lib->eh_frame.data = read_section_data(lib->fd, &ehdr, sh);
       lib->eh_frame.size = sh->sh_size;
diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.h b/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.h
index d5aa74e73ad74..be0b584108b85 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.h
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.h
@@ -36,7 +36,6 @@
 
 // .eh_frame data
 typedef struct eh_frame_info {
-  uintptr_t library_base_addr;
   uintptr_t v_addr;
   unsigned char* data;
   int size;

From 0682a312f8202592e2ad6bc2210b27f5190c4ce0 Mon Sep 17 00:00:00 2001
From: Yasumasa Suenaga <yasuenag@gmail.com>
Date: Sun, 19 Apr 2026 14:53:10 +0900
Subject: [PATCH 2/7] Move debuginfo related code to salibelf from symtab

---
 .../linux/native/libsaproc/salibelf.c         | 249 +++++++++++++++++
 .../linux/native/libsaproc/salibelf.h         |  12 +
 .../linux/native/libsaproc/symtab.c           | 260 +-----------------
 3 files changed, 268 insertions(+), 253 deletions(-)

diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.c b/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.c
index 6e39b95e7eca5..ee8db71d754b6 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.c
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.c
@@ -29,6 +29,255 @@
 
 extern void print_debug(const char*,...);
 
+// Directory that contains global debuginfo files.  In theory it
+// should be possible to change this, but in a Java environment there
+// is no obvious place to put a user interface to do it.  Maybe this
+// could be set with an environment variable.
+static const char debug_file_directory[] = "/usr/lib/debug";
+
+/* The CRC used in gnu_debuglink, retrieved from
+   http://sourceware.org/gdb/current/onlinedocs/gdb/Separate-Debug-Files.html#Separate-Debug-Files. */
+unsigned int gnu_debuglink_crc32 (unsigned int crc,
+                                  unsigned char *buf, size_t len)
+{
+  static const unsigned int crc32_table[256] =
+    {
+      0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
+      0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
+      0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
+      0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
+      0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
+      0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
+      0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
+      0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+      0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
+      0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
+      0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
+      0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+      0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
+      0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
+      0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
+      0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+      0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
+      0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+      0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
+      0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
+      0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
+      0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
+      0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
+      0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+      0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
+      0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
+      0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
+      0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
+      0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
+      0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
+      0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
+      0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+      0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
+      0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
+      0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
+      0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+      0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
+      0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
+      0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
+      0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+      0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
+      0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+      0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
+      0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
+      0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
+      0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
+      0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
+      0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+      0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
+      0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
+      0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
+      0x2d02ef8d
+    };
+  unsigned char *end;
+
+  crc = ~crc & 0xffffffff;
+  for (end = buf + len; buf < end; ++buf)
+    crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8);
+  return ~crc & 0xffffffff;
+}
+
+/* Open a debuginfo file and check its CRC.  If it exists and the CRC
+   matches return its fd.  */
+static int
+open_debug_file (const char *pathname, unsigned int crc)
+{
+  unsigned int file_crc = 0;
+  unsigned char buffer[8 * 1024];
+
+  int fd = pathmap_open(pathname);
+
+  if (fd < 0)
+    return -1;
+
+  lseek(fd, 0, SEEK_SET);
+
+  for (;;) {
+    int len = read(fd, buffer, sizeof buffer);
+    if (len <= 0)
+      break;
+    file_crc = gnu_debuglink_crc32(file_crc, buffer, len);
+  }
+
+  if (crc == file_crc)
+    return fd;
+  else {
+    close(fd);
+    return -1;
+  }
+}
+
+/* Look for a ".gnu_debuglink" section.  If one exists, try to open a
+   suitable debuginfo file.  */
+static int open_debuginfo_from_debug_link(const char *name,
+                                          int fd,
+                                          ELF_EHDR *ehdr,
+                                          struct elf_section *scn_cache)
+{
+  int debug_fd;
+  struct elf_section *debug_link = find_section_by_name(".gnu_debuglink", fd, ehdr,
+                                                         scn_cache);
+  if (debug_link == NULL)
+    return -1;
+  char *debug_filename = debug_link->c_data;
+  int offset = (strlen(debug_filename) + 4) >> 2;
+  static unsigned int crc;
+  crc = ((unsigned int*)debug_link->c_data)[offset];
+  char *debug_pathname = malloc(strlen(debug_filename)
+                                + strlen(name)
+                                + strlen(".debug/")
+                                + strlen(debug_file_directory)
+                                + 2);
+  if (debug_pathname == NULL) {
+    return -1;
+  }
+  strcpy(debug_pathname, name);
+  char *last_slash = strrchr(debug_pathname, '/');
+  if (last_slash == NULL) {
+    free(debug_pathname);
+    return -1;
+  }
+
+  /* Look in the same directory as the object.  */
+  strcpy(last_slash+1, debug_filename);
+  debug_fd = open_debug_file(debug_pathname, crc);
+  if (debug_fd >= 0) {
+    free(debug_pathname);
+    return debug_fd;
+  }
+
+  /* Look in a subdirectory named ".debug".  */
+  strcpy(last_slash+1, ".debug/");
+  strcat(last_slash, debug_filename);
+
+  debug_fd = open_debug_file(debug_pathname, crc);
+  if (debug_fd >= 0) {
+    free(debug_pathname);
+    return debug_fd;
+  }
+  /* Look in /usr/lib/debug + the full pathname.  */
+  strcpy(debug_pathname, debug_file_directory);
+  strcat(debug_pathname, name);
+  last_slash = strrchr(debug_pathname, '/');
+  strcpy(last_slash+1, debug_filename);
+
+  debug_fd = open_debug_file(debug_pathname, crc);
+  if (debug_fd >= 0) {
+    free(debug_pathname);
+    return debug_fd;
+  }
+
+  free(debug_pathname);
+  return -1;
+}
+
+static char* build_id_to_debug_filename (size_t size, unsigned char* data) {
+  char *filename, *s;
+
+  filename = malloc(strlen (debug_file_directory) + (sizeof "/.build-id/" - 1) + 1
+                    + 2 * size + (sizeof ".debug" - 1) + 1);
+  if (filename == NULL) {
+    return NULL;
+  }
+  s = filename + sprintf (filename, "%s/.build-id/", debug_file_directory);
+  if (size > 0) {
+    size--;
+    s += sprintf (s, "%02x", *data++);
+  }
+  if (size > 0) {
+    *s++ = '/';
+  }
+  while (size-- > 0) {
+    s += sprintf (s, "%02x", *data++);
+  }
+  strcpy (s, ".debug");
+
+  return filename;
+}
+
+static int open_debuginfo_from_build_id(ELF_SHDR* shbuf, ELF_EHDR* ehdr, struct elf_section* scn_cache) {
+#ifdef NT_GNU_BUILD_ID
+  int cnt = 0;
+  ELF_SHDR* cursct = NULL;
+
+  // First we look for a Build ID
+  for (cursct = shbuf, cnt = 0; cnt < ehdr->e_shnum; cnt++) {
+    if (cursct->sh_type == SHT_NOTE) {
+      Elf64_Nhdr *note = (Elf64_Nhdr *)scn_cache[cnt].c_data;
+      if (note->n_type == NT_GNU_BUILD_ID) {
+        unsigned char *bytes = (unsigned char*)(note+1) + note->n_namesz;
+        char *filename = build_id_to_debug_filename(note->n_descsz, bytes);
+        if (filename != NULL) {
+          int fd = pathmap_open(filename);
+          free(filename);
+          return fd;
+        }
+      }
+    }
+    cursct++;
+  }
+#endif
+  return -1;
+}
+
+int open_debuginfo(const char* filename, int fd) {
+  // prepare (load ELF sections)
+  ELF_EHDR ehdr;
+  read_elf_header(fd, &ehdr);
+  ELF_SHDR* shbuf = read_section_header_table(fd, &ehdr);
+  struct elf_section *scn_cache = (struct elf_section *)calloc(ehdr.e_shnum, sizeof(struct elf_section));
+  for (int cnt = 0; cnt < ehdr.e_shnum; cnt++) {
+    scn_cache[cnt].c_shdr = &shbuf[cnt];
+    if (shbuf[cnt].sh_type == SHT_NOTE || shbuf[cnt].sh_type == SHT_STRTAB) {
+      scn_cache[cnt].c_data = read_section_data(fd, &ehdr, &shbuf[cnt]);
+    }
+  }
+
+  // attempt to open debuginfo
+  int debug_fd = open_debuginfo_from_debug_link(filename, fd, &ehdr, scn_cache);
+  if (debug_fd == -1) {
+    // try again with build id.
+    debug_fd = open_debuginfo_from_build_id(shbuf, &ehdr, scn_cache);
+  }
+
+  // cleanup
+  for (int cnt = 0; cnt < ehdr.e_shnum; cnt++) {
+    if (shbuf[cnt].sh_type == SHT_NOTE) {
+      free(scn_cache[cnt].c_data);
+    }
+  }
+  free(scn_cache);
+  free(shbuf);
+
+  return debug_fd;
+}
+
 // ELF file parsing helpers. Note that we do *not* use libelf here.
 int read_elf_header(int fd, ELF_EHDR* ehdr) {
    if (pread(fd, ehdr, sizeof (ELF_EHDR), 0) != sizeof (ELF_EHDR) ||
diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.h b/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.h
index 59b5039416e85..a675b6f92e304 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.h
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.h
@@ -34,6 +34,13 @@ struct elf_section {
   void       *c_data;
 };
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// open debuginfo
+int open_debuginfo(const char* filename, int fd);
+
 // read ELF file header.
 int read_elf_header(int fd, ELF_EHDR* ehdr);
 
@@ -60,4 +67,9 @@ struct elf_section *find_section_by_name(char *name,
                                          int fd,
                                          ELF_EHDR *ehdr,
                                          struct elf_section *scn_cache);
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* _SALIBELF_H_ */
diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/symtab.c b/src/jdk.hotspot.agent/linux/native/libsaproc/symtab.c
index 8f8ce28be1e78..153ea1e73139d 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/symtab.c
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/symtab.c
@@ -49,245 +49,20 @@ typedef struct symtab {
 } symtab_t;
 
 
-// Directory that contains global debuginfo files.  In theory it
-// should be possible to change this, but in a Java environment there
-// is no obvious place to put a user interface to do it.  Maybe this
-// could be set with an environment variable.
-static const char debug_file_directory[] = "/usr/lib/debug";
-
-/* The CRC used in gnu_debuglink, retrieved from
-   http://sourceware.org/gdb/current/onlinedocs/gdb/Separate-Debug-Files.html#Separate-Debug-Files. */
-unsigned int gnu_debuglink_crc32 (unsigned int crc,
-                                  unsigned char *buf, size_t len)
-{
-  static const unsigned int crc32_table[256] =
-    {
-      0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
-      0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
-      0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
-      0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
-      0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
-      0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
-      0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
-      0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
-      0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
-      0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
-      0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
-      0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
-      0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
-      0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
-      0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
-      0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
-      0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
-      0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
-      0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
-      0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
-      0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
-      0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
-      0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
-      0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
-      0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
-      0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
-      0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
-      0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
-      0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
-      0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
-      0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
-      0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
-      0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
-      0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
-      0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
-      0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
-      0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
-      0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
-      0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
-      0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
-      0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
-      0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
-      0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
-      0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
-      0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
-      0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
-      0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
-      0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
-      0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
-      0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
-      0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
-      0x2d02ef8d
-    };
-  unsigned char *end;
-
-  crc = ~crc & 0xffffffff;
-  for (end = buf + len; buf < end; ++buf)
-    crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8);
-  return ~crc & 0xffffffff;
-}
-
-/* Open a debuginfo file and check its CRC.  If it exists and the CRC
-   matches return its fd.  */
-static int
-open_debug_file (const char *pathname, unsigned int crc)
-{
-  unsigned int file_crc = 0;
-  unsigned char buffer[8 * 1024];
-
-  int fd = pathmap_open(pathname);
-
-  if (fd < 0)
-    return -1;
-
-  lseek(fd, 0, SEEK_SET);
-
-  for (;;) {
-    int len = read(fd, buffer, sizeof buffer);
-    if (len <= 0)
-      break;
-    file_crc = gnu_debuglink_crc32(file_crc, buffer, len);
-  }
-
-  if (crc == file_crc)
-    return fd;
-  else {
-    close(fd);
-    return -1;
-  }
-}
-
-/* Look for a ".gnu_debuglink" section.  If one exists, try to open a
-   suitable debuginfo file.  */
-static int open_file_from_debug_link(const char *name,
-                                     int fd,
-                                     ELF_EHDR *ehdr,
-                                     struct elf_section *scn_cache)
-{
-  int debug_fd;
-  struct elf_section *debug_link = find_section_by_name(".gnu_debuglink", fd, ehdr,
-                                                         scn_cache);
-  if (debug_link == NULL)
-    return -1;
-  char *debug_filename = debug_link->c_data;
-  int offset = (strlen(debug_filename) + 4) >> 2;
-  static unsigned int crc;
-  crc = ((unsigned int*)debug_link->c_data)[offset];
-  char *debug_pathname = malloc(strlen(debug_filename)
-                                + strlen(name)
-                                + strlen(".debug/")
-                                + strlen(debug_file_directory)
-                                + 2);
-  if (debug_pathname == NULL) {
-    return -1;
-  }
-  strcpy(debug_pathname, name);
-  char *last_slash = strrchr(debug_pathname, '/');
-  if (last_slash == NULL) {
-    free(debug_pathname);
-    return -1;
-  }
-
-  /* Look in the same directory as the object.  */
-  strcpy(last_slash+1, debug_filename);
-  debug_fd = open_debug_file(debug_pathname, crc);
-  if (debug_fd >= 0) {
-    free(debug_pathname);
-    return debug_fd;
-  }
-
-  /* Look in a subdirectory named ".debug".  */
-  strcpy(last_slash+1, ".debug/");
-  strcat(last_slash, debug_filename);
-
-  debug_fd = open_debug_file(debug_pathname, crc);
-  if (debug_fd >= 0) {
-    free(debug_pathname);
-    return debug_fd;
-  }
-
-  /* Look in /usr/lib/debug + the full pathname.  */
-  strcpy(debug_pathname, debug_file_directory);
-  strcat(debug_pathname, name);
-  last_slash = strrchr(debug_pathname, '/');
-  strcpy(last_slash+1, debug_filename);
-
-  debug_fd = open_debug_file(debug_pathname, crc);
-  if (debug_fd >= 0) {
-    free(debug_pathname);
-    return debug_fd;
-  }
-
-  free(debug_pathname);
-  return -1;
-}
-
 static struct symtab* build_symtab_internal(int fd, const char *filename, bool try_debuginfo);
 
-/* Look for a ".gnu_debuglink" section.  If one exists, try to open a
-   suitable debuginfo file and read a symbol table from it.  */
-static struct symtab *build_symtab_from_debug_link(const char *name,
-                                     int fd,
-                                     ELF_EHDR *ehdr,
-                                     struct elf_section *scn_cache)
-{
-  fd = open_file_from_debug_link(name, fd, ehdr, scn_cache);
-
-  if (fd >= 0) {
-    struct symtab *symtab = build_symtab_internal(fd, NULL, /* try_debuginfo */ false);
-    close(fd);
+/* Try to open a suitable debuginfo file and read a symbol table from it. */
+static struct symtab *build_symtab_from_debuginfo(const char* filename, int fd) {
+  int debug_fd = open_debuginfo(filename, fd);
+  if (debug_fd >= 0) {
+    struct symtab *symtab = build_symtab_internal(debug_fd, NULL, /* try_debuginfo */ false);
+    close(debug_fd);
     return symtab;
   }
 
   return NULL;
 }
 
-// Given a build_id, find the associated debuginfo file
-static char *
-build_id_to_debug_filename (size_t size, unsigned char *data)
-{
-  char *filename, *s;
-
-  filename = malloc(strlen (debug_file_directory) + (sizeof "/.build-id/" - 1) + 1
-                    + 2 * size + (sizeof ".debug" - 1) + 1);
-  if (filename == NULL) {
-    return NULL;
-  }
-  s = filename + sprintf (filename, "%s/.build-id/", debug_file_directory);
-  if (size > 0)
-    {
-      size--;
-      s += sprintf (s, "%02x", *data++);
-    }
-  if (size > 0)
-    *s++ = '/';
-  while (size-- > 0)
-    s += sprintf (s, "%02x", *data++);
-  strcpy (s, ".debug");
-
-  return filename;
-}
-
-// Read a build ID note.  Try to open any associated debuginfo file
-// and return its symtab
-static struct symtab* build_symtab_from_build_id(Elf64_Nhdr *note)
-{
-  int fd;
-  struct symtab *symtab = NULL;
-
-  unsigned char *bytes
-    = (unsigned char*)(note+1) + note->n_namesz;
-  char *filename
-    = (build_id_to_debug_filename (note->n_descsz, bytes));
-  if (filename == NULL) {
-    return NULL;
-  }
-  fd = pathmap_open(filename);
-  if (fd >= 0) {
-    symtab = build_symtab_internal(fd, NULL, /* try_debuginfo */ false);
-    close(fd);
-  }
-  free(filename);
-
-  return symtab;
-}
-
 // read symbol table from given fd.  If try_debuginfo) is true, also
 // try to open an associated debuginfo file
 static struct symtab* build_symtab_internal(int fd, const char *filename, bool try_debuginfo) {
@@ -464,28 +239,7 @@ static struct symtab* build_symtab_internal(int fd, const char *filename, bool t
     // the debuginfo file.  We stash a copy of the old symtab in case
     // there is no debuginfo.
     struct symtab* prev_symtab = symtab;
-    symtab = NULL;
-
-#ifdef NT_GNU_BUILD_ID
-    // First we look for a Build ID
-    for (cursct = shbuf, cnt = 0;
-         symtab == NULL && cnt < ehdr.e_shnum;
-         cnt++) {
-      if (cursct->sh_type == SHT_NOTE) {
-        Elf64_Nhdr *note = (Elf64_Nhdr *)scn_cache[cnt].c_data;
-        if (note->n_type == NT_GNU_BUILD_ID) {
-          symtab = build_symtab_from_build_id(note);
-        }
-      }
-      cursct++;
-    }
-#endif
-
-    // Then, if that doesn't work, the debug link
-    if (symtab == NULL) {
-      symtab = build_symtab_from_debug_link(filename, fd, &ehdr,
-                                            scn_cache);
-    }
+    symtab = build_symtab_from_debuginfo(filename, fd);
 
     // If we still haven't found a symtab, use the object's own symtab.
     if (symtab != NULL) {

From 662b373f316eeb920dc7b6a0df155a5b7c852ef1 Mon Sep 17 00:00:00 2001
From: Yasumasa Suenaga <yasuenag@gmail.com>
Date: Sun, 19 Apr 2026 14:54:30 +0900
Subject: [PATCH 3/7] Rename "eh_frame_info" to "frame_info"

---
 src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp | 10 +++++-----
 src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.hpp |  2 +-
 .../linux/native/libsaproc/libproc_impl.c              | 10 +++++-----
 .../linux/native/libsaproc/libproc_impl.h              |  8 ++++----
 4 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp b/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp
index 8ce0046fdb732..85fe67c5d6098 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp
@@ -268,14 +268,14 @@ uint32_t DwarfParser::get_decoded_value() {
   //   https://gcc.gnu.org/ml/gcc-help/2010-09/msg00166.html
 #if defined(_LP64)
   if (size == 8) {
-    result += _lib->eh_frame.v_addr + static_cast<uintptr_t>(_buf - _lib->eh_frame.data);
+    result += _lib->frame.v_addr + static_cast<uintptr_t>(_buf - _lib->frame.data);
     size = 4;
   } else
 #endif
   if ((_encoding & 0x70) == 0x10) { // 0x10 = DW_EH_PE_pcrel
-    result += _lib->eh_frame.v_addr + static_cast<uintptr_t>(_buf - _lib->eh_frame.data);
+    result += _lib->frame.v_addr + static_cast<uintptr_t>(_buf - _lib->frame.data);
   } else  if (size == 2) {
-    result = static_cast<int>(result) + _lib->eh_frame.v_addr + static_cast<uintptr_t>(_buf - _lib->eh_frame.data);
+    result = static_cast<int>(result) + _lib->frame.v_addr + static_cast<uintptr_t>(_buf - _lib->frame.data);
     size = 4;
   }
 
@@ -322,8 +322,8 @@ unsigned int DwarfParser::get_pc_range() {
 
 bool DwarfParser::process_dwarf(const uintptr_t pc) {
   // https://refspecs.linuxfoundation.org/LSB_3.0.0/LSB-PDA/LSB-PDA/ehframechpt.html
-  _buf = _lib->eh_frame.data;
-  unsigned char *end = _lib->eh_frame.data + _lib->eh_frame.size;
+  _buf = _lib->frame.data;
+  unsigned char *end = _lib->frame.data + _lib->frame.size;
   while (_buf <= end) {
     uint64_t length = get_entry_length();
     if (length == 0L) {
diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.hpp b/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.hpp
index 2bfdba65a78f7..33b18f91f1d1f 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.hpp
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.hpp
@@ -93,7 +93,7 @@ class DwarfParser {
     }
 
     bool is_parseable() {
-      return _lib->eh_frame.data != NULL;
+      return _lib->frame.data != NULL;
     }
 };
 
diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.c b/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.c
index 52d2ad5f404d0..cc8f956bb0c17 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.c
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.c
@@ -128,7 +128,7 @@ static void destroy_lib_info(struct ps_prochandle* ph) {
      if (lib->symtab) {
         destroy_symtab(lib->symtab);
      }
-     free(lib->eh_frame.data);
+     free(lib->frame.data);
      free(lib);
      lib = next;
    }
@@ -231,9 +231,9 @@ bool read_eh_frame(struct ps_prochandle* ph, lib_info* lib) {
 
   for (cnt = 0, sh = shbuf; cnt < ehdr.e_shnum; cnt++, sh++) {
     if (strcmp(".eh_frame", sh->sh_name + strtab) == 0) {
-      lib->eh_frame.v_addr = sh->sh_addr;
-      lib->eh_frame.data = read_section_data(lib->fd, &ehdr, sh);
-      lib->eh_frame.size = sh->sh_size;
+      lib->frame.v_addr = sh->sh_addr;
+      lib->frame.data = read_section_data(lib->fd, &ehdr, sh);
+      lib->frame.size = sh->sh_size;
       break;
     }
   }
@@ -241,7 +241,7 @@ bool read_eh_frame(struct ps_prochandle* ph, lib_info* lib) {
   free(strtab);
   free(shbuf);
   lseek(lib->fd, current_pos, SEEK_SET);
-  return lib->eh_frame.data != NULL;
+  return lib->frame.data != NULL;
 }
 
 lib_info* add_lib_info_fd(struct ps_prochandle* ph, const char* libname, int fd, uintptr_t base) {
diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.h b/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.h
index be0b584108b85..44dc902d7c030 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.h
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.h
@@ -34,12 +34,12 @@
 
 #define BUF_SIZE     (PATH_MAX + NAME_MAX + 1)
 
-// .eh_frame data
-typedef struct eh_frame_info {
+// frame data (.eh_frame / .debug_frame)
+typedef struct frame_info {
   uintptr_t v_addr;
   unsigned char* data;
   int size;
-} eh_frame_info;
+} frame_info;
 
 // list of shared objects
 typedef struct lib_info {
@@ -48,7 +48,7 @@ typedef struct lib_info {
   uintptr_t        end;
   uintptr_t        exec_start;
   uintptr_t        exec_end;
-  eh_frame_info    eh_frame;
+  frame_info       frame;
   struct symtab*   symtab;
   int              fd;        // file descriptor for lib
   struct lib_info* next;

From 0e4477ac9bc95026283c1ad085c1bbb43b399ef0 Mon Sep 17 00:00:00 2001
From: Yasumasa Suenaga <yasuenag@gmail.com>
Date: Sun, 19 Apr 2026 15:07:37 +0900
Subject: [PATCH 4/7] Use .debug_frame if DWARF parser could not find PC from
 .eh_frame

---
 .../linux/native/libsaproc/dwarf.cpp          | 70 +++++++++++++++----
 .../linux/native/libsaproc/dwarf.hpp          |  2 +-
 .../linux/native/libsaproc/libproc_impl.c     | 27 +++----
 .../linux/native/libsaproc/libproc_impl.h     |  9 +++
 .../linux/native/libsaproc/ps_proc.c          |  5 --
 5 files changed, 82 insertions(+), 31 deletions(-)

diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp b/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp
index 85fe67c5d6098..d21eb3c5d881e 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.cpp
@@ -23,10 +23,12 @@
  *
  */
 
+#include <cstdlib>
 #include <cstring>
 #include <stack>
 
 #include "dwarf.hpp"
+#include "salibelf.h"
 #include "libproc_impl.h"
 
 DwarfParser::DwarfParser(lib_info *lib) : _lib(lib),
@@ -75,7 +77,7 @@ uintptr_t DwarfParser::read_leb(bool sign) {
 uint64_t DwarfParser::get_entry_length() {
   uint64_t length = *(reinterpret_cast<uint32_t *>(_buf));
   _buf += 4;
-  if (length == 0xffffffff) {
+  if (!_lib->frame.is_debug_frame && length == 0xffffffff) {
     length = *(reinterpret_cast<uint64_t *>(_buf));
     _buf += 8;
   }
@@ -84,7 +86,11 @@ uint64_t DwarfParser::get_entry_length() {
 
 bool DwarfParser::process_cie(unsigned char *start_of_entry, uint32_t id) {
   unsigned char *orig_pos = _buf;
-  _buf = start_of_entry - id;
+
+  // CIE pointer means the offset from FDE in .eh_frame.
+  // In .debug_frame, CIE pointer means the offset from start of .debug_frame .
+  _buf = _lib->frame.is_debug_frame ? _lib->frame.data + id
+                                    : start_of_entry - id;
 
   uint64_t length = get_entry_length();
   if (length == 0L) {
@@ -92,8 +98,8 @@ bool DwarfParser::process_cie(unsigned char *start_of_entry, uint32_t id) {
   }
   unsigned char *end = _buf + length;
 
-  _buf += 4; // Skip ID (This value of CIE would be always 0)
-  _buf++;    // Skip version (assume to be "1")
+  _buf += 4; // Skip ID (This value of CIE would be always 0 in .eh_frame / 0xffffffff in .debug_frame)
+  _buf++;    // Skip version
 
   char *augmentation_string = reinterpret_cast<char *>(_buf);
   bool has_ehdata = (strcmp("eh", augmentation_string) == 0);
@@ -327,15 +333,28 @@ bool DwarfParser::process_dwarf(const uintptr_t pc) {
   while (_buf <= end) {
     uint64_t length = get_entry_length();
     if (length == 0L) {
-      return false;
+      break; // it means "terminator" in .eh_frame, so go through to .debug_frame
     }
     unsigned char *next_entry = _buf + length;
     unsigned char *start_of_entry = _buf;
     uint32_t id = *(reinterpret_cast<uint32_t *>(_buf));
     _buf += 4;
-    if (id != 0) { // FDE
-      uintptr_t pc_begin = get_decoded_value() + _lib->base;
-      uintptr_t pc_end = pc_begin + get_pc_range();
+    // ID for CIE is 0 in .eh_frame, 0xffffffff in .debug_frame
+    bool is_fde = (_lib->frame.is_debug_frame ? 0xffffffff : 0) != id;
+    if (is_fde) {
+      uintptr_t begin_ofs = 0L;
+      uintptr_t inst_sz = 0L;
+      if (_lib->frame.is_debug_frame) {
+        begin_ofs = *(reinterpret_cast<uintptr_t *>(_buf));
+        _buf += sizeof(void*);
+        inst_sz = *(reinterpret_cast<uintptr_t *>(_buf));
+        _buf += sizeof(void*);
+      } else {
+        begin_ofs = get_decoded_value();
+        inst_sz = get_pc_range();
+      }
+      uintptr_t pc_begin = begin_ofs + _lib->base;
+      uintptr_t pc_end = pc_begin + inst_sz;
 
       if ((pc >= pc_begin) && (pc < pc_end)) {
         // Process CIE
@@ -343,9 +362,11 @@ bool DwarfParser::process_dwarf(const uintptr_t pc) {
           return false;
         }
 
-        // Skip Augumenation
-        uintptr_t augmentation_length = read_leb(false);
-        _buf += augmentation_length; // skip
+        // Skip Augumenation if .eh_frame
+        if (!_lib->frame.is_debug_frame) {
+          uintptr_t augmentation_length = read_leb(false);
+          _buf += augmentation_length; // skip
+        }
 
         // Process FDE
         parse_dwarf_instructions(pc_begin, pc, next_entry);
@@ -356,5 +377,30 @@ bool DwarfParser::process_dwarf(const uintptr_t pc) {
     _buf = next_entry;
   }
 
-  return false;
+  bool result = false;
+  // try again with .debug_frame section if it hasn't been tried yet.
+  if (!_lib->frame.tried_debug_frame && _lib->fd != -1) {
+    // attempts to load .debug_frame from executables.
+    frame_info frame = {};
+    if (!read_frame(".debug_frame", _lib->fd, &frame)) {
+      // attempts again to load .debug_frame from debuginfo if it could not be loaded from executables.
+      int debug_fd = open_debuginfo(_lib->name, _lib->fd);
+      if (debug_fd != -1 && read_frame(".debug_frame", debug_fd, &frame)) {
+        close(debug_fd);
+      }
+    }
+    frame.tried_debug_frame = true;
+    _lib->frame.tried_debug_frame = true;
+
+    // try process_dwarf() again with .debug_frame.
+    if (frame.data != NULL) {
+      if (_lib->frame.data != NULL) {
+        free(_lib->frame.data);
+      }
+      memcpy(&_lib->frame, &frame, sizeof(frame_info));
+      result = process_dwarf(pc);
+    }
+  }
+
+  return result;
 }
diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.hpp b/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.hpp
index 33b18f91f1d1f..130efe37aaeb7 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.hpp
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/dwarf.hpp
@@ -61,7 +61,7 @@ struct DwarfState {
  */
 class DwarfParser {
   private:
-    const lib_info *_lib;
+    lib_info *_lib;
     unsigned char *_buf;
     unsigned char _encoding;
     unsigned int _code_factor;
diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.c b/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.c
index cc8f956bb0c17..d6542c2219f23 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.c
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.c
@@ -214,7 +214,7 @@ static bool fill_addr_info(lib_info* lib) {
   return (lib->end != -1L) && (lib->exec_start != -1L) && (lib->exec_end != -1L);
 }
 
-bool read_eh_frame(struct ps_prochandle* ph, lib_info* lib) {
+bool read_frame(const char* section, int fd, frame_info* frame) {
   off_t current_pos = -1;
   ELF_EHDR ehdr;
   ELF_SHDR* shbuf = NULL;
@@ -222,26 +222,27 @@ bool read_eh_frame(struct ps_prochandle* ph, lib_info* lib) {
   char* strtab = NULL;
   int cnt;
 
-  current_pos = lseek(lib->fd, (off_t)0L, SEEK_CUR);
-  lseek(lib->fd, (off_t)0L, SEEK_SET);
+  current_pos = lseek(fd, (off_t)0L, SEEK_CUR);
+  lseek(fd, (off_t)0L, SEEK_SET);
 
-  read_elf_header(lib->fd, &ehdr);
-  shbuf = read_section_header_table(lib->fd, &ehdr);
-  strtab = read_section_data(lib->fd, &ehdr, &shbuf[ehdr.e_shstrndx]);
+  read_elf_header(fd, &ehdr);
+  shbuf = read_section_header_table(fd, &ehdr);
+  strtab = read_section_data(fd, &ehdr, &shbuf[ehdr.e_shstrndx]);
 
   for (cnt = 0, sh = shbuf; cnt < ehdr.e_shnum; cnt++, sh++) {
-    if (strcmp(".eh_frame", sh->sh_name + strtab) == 0) {
-      lib->frame.v_addr = sh->sh_addr;
-      lib->frame.data = read_section_data(lib->fd, &ehdr, sh);
-      lib->frame.size = sh->sh_size;
+    if (strcmp(section, sh->sh_name + strtab) == 0) {
+      frame->v_addr = sh->sh_addr;
+      frame->data = read_section_data(fd, &ehdr, sh);
+      frame->size = sh->sh_size;
+      frame->is_debug_frame = strcmp(section, ".debug_frame") == 0;
       break;
     }
   }
 
   free(strtab);
   free(shbuf);
-  lseek(lib->fd, current_pos, SEEK_SET);
-  return lib->frame.data != NULL;
+  lseek(fd, current_pos, SEEK_SET);
+  return frame->data != NULL;
 }
 
 lib_info* add_lib_info_fd(struct ps_prochandle* ph, const char* libname, int fd, uintptr_t base) {
@@ -285,7 +286,7 @@ lib_info* add_lib_info_fd(struct ps_prochandle* ph, const char* libname, int fd,
    }
 
    if (fill_addr_info(newlib)) {
-     if (!read_eh_frame(ph, newlib)) {
+     if (!read_frame(".eh_frame", newlib->fd, &newlib->frame)) {
        print_debug("Could not find .eh_frame section in %s\n", newlib->name);
      }
    } else {
diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.h b/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.h
index 44dc902d7c030..0e7feaf0b23bc 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.h
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/libproc_impl.h
@@ -39,6 +39,12 @@ typedef struct frame_info {
   uintptr_t v_addr;
   unsigned char* data;
   int size;
+
+  // Following fields should be declared as int instead of bool
+  // because "bool" would be defined as int in C in libproc.h.
+  // It causes unexpected memory access.
+  int is_debug_frame; // true if this info comes from .debug_frame
+  int tried_debug_frame; // true if .debug_frame was tried to load.
 } frame_info;
 
 // list of shared objects
@@ -130,6 +136,9 @@ void print_debug(const char* format,...);
 void print_error(const char* format,...);
 bool is_debug();
 
+// read frame information for unwinding from specified ELF section.
+bool read_frame(const char* section, int fd, frame_info* frame);
+
 // deletes a thread from the thread list
 void delete_thread_info(struct ps_prochandle* ph, thread_info* thr);
 
diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/ps_proc.c b/src/jdk.hotspot.agent/linux/native/libsaproc/ps_proc.c
index 9cbde7319f016..530d1abd1822c 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/ps_proc.c
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/ps_proc.c
@@ -408,11 +408,6 @@ static bool read_lib_info(struct ps_prochandle* ph) {
 #endif
        if ((lib = add_lib_info(ph, word[5], (uintptr_t)base)) == NULL)
           continue; // ignore, add_lib_info prints error
-
-       // we don't need to keep the library open, symtab is already
-       // built. Only for core dump we need to keep the fd open.
-       close(lib->fd);
-       lib->fd = -1;
     }
   }
   fclose(fp);

From ec4a08d3d4457c1bb70bb1a73e9978fd018eab1a Mon Sep 17 00:00:00 2001
From: Yasumasa Suenaga <yasuenag@gmail.com>
Date: Sun, 19 Apr 2026 15:10:06 +0900
Subject: [PATCH 5/7] Validate sender SP before to return sender frame in
 LinuxAMD64CFrame.java

---
 .../jvm/hotspot/debugger/linux/amd64/LinuxAMD64CFrame.java | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/linux/amd64/LinuxAMD64CFrame.java b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/linux/amd64/LinuxAMD64CFrame.java
index e58e2facdd7c9..35af269196710 100644
--- a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/linux/amd64/LinuxAMD64CFrame.java
+++ b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/linux/amd64/LinuxAMD64CFrame.java
@@ -79,6 +79,11 @@ private Address getSenderCFA(DwarfParser senderDwarf, Address senderSP, Address
      };
    }
 
+   // In SysV AMD64, the stack must be consumed because return address would be stored on the stack.
+   protected boolean isValidFrame(Address senderCFA, Address senderFP, Address senderSP) {
+     return super.isValidFrame(senderCFA, senderFP) && sp().lessThan(senderSP);
+   }
+
    @Override
    public CFrame sender(ThreadProxy th, Address senderSP, Address senderFP, Address senderPC) {
      if (linuxDbg().isSignalTrampoline(pc())) {
@@ -118,7 +123,7 @@ public CFrame sender(ThreadProxy th, Address senderSP, Address senderFP, Address
 
      try {
        Address senderCFA = getSenderCFA(senderDwarf, senderSP, senderFP);
-       return isValidFrame(senderCFA, senderFP)
+       return isValidFrame(senderCFA, senderFP, senderSP)
          ? new LinuxAMD64CFrame(linuxDbg(), senderSP, senderFP, senderCFA, senderPC, senderDwarf, fallback)
          : null;
      } catch (DebuggerException e) {

From de27835d7ae58bc7547f25fefe1613af47757c82 Mon Sep 17 00:00:00 2001
From: Yasumasa Suenaga <yasuenag@gmail.com>
Date: Sun, 19 Apr 2026 15:13:01 +0900
Subject: [PATCH 6/7] Re-enable mixed jstack tests on musl C

---
 test/hotspot/jtreg/serviceability/sa/ClhsdbPstack.java     | 4 ----
 .../jtreg/serviceability/sa/TestJhsdbJstackMixed.java      | 6 ------
 .../jtreg/serviceability/sa/TestJhsdbJstackMixedCore.java  | 5 -----
 .../serviceability/sa/TestJhsdbJstackMixedWithXComp.java   | 7 -------
 .../serviceability/sa/TestJhsdbJstackPrintVMLocks.java     | 6 ------
 5 files changed, 28 deletions(-)

diff --git a/test/hotspot/jtreg/serviceability/sa/ClhsdbPstack.java b/test/hotspot/jtreg/serviceability/sa/ClhsdbPstack.java
index 6921a7ec0ca34..51738be355462 100644
--- a/test/hotspot/jtreg/serviceability/sa/ClhsdbPstack.java
+++ b/test/hotspot/jtreg/serviceability/sa/ClhsdbPstack.java
@@ -54,10 +54,6 @@
 public class ClhsdbPstack {
 
     public static void main(String[] args) throws Exception {
-        if (Platform.isMusl()) {
-            throw new SkippedException("This test does not work on musl libc.");
-        }
-
         boolean withCore = Boolean.parseBoolean(args[0]);
         System.out.println("Starting ClhsdbPstack test: withCore==" + withCore);
 
diff --git a/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackMixed.java b/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackMixed.java
index a5750edf360fc..e3808aa670628 100644
--- a/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackMixed.java
+++ b/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackMixed.java
@@ -33,8 +33,6 @@
 import jdk.test.lib.apps.LingeredApp;
 import jdk.test.lib.process.OutputAnalyzer;
 
-import jtreg.SkippedException;
-
 /**
  * @test
  * @key randomness
@@ -176,10 +174,6 @@ private static void runJstackMixedInLoop(LingeredApp app) throws Exception {
     }
 
     public static void main(String... args) throws Exception {
-        if (Platform.isMusl()) {
-            throw new SkippedException("This test does not work on musl libc.");
-        }
-
         SATestUtils.skipIfCannotAttach(); // throws SkippedException if attach not expected to work.
         LingeredApp app = null;
 
diff --git a/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackMixedCore.java b/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackMixedCore.java
index 99232ed981315..55107727b2bb6 100644
--- a/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackMixedCore.java
+++ b/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackMixedCore.java
@@ -26,7 +26,6 @@
 
 import jdk.test.lib.JDKToolFinder;
 import jdk.test.lib.JDKToolLauncher;
-import jdk.test.lib.Platform;
 import jdk.test.lib.SA.SATestUtils;
 import jdk.test.lib.Utils;
 import jdk.test.lib.apps.LingeredApp;
@@ -72,10 +71,6 @@ private static void runJstackMixed(String coreFileName) throws Exception {
     }
 
     public static void main(String... args) throws Throwable {
-        if (Platform.isMusl()) {
-            throw new SkippedException("This test does not work on musl libc.");
-        }
-
         // Check whether the symbol of signal trampoline is available.
         var libc = SATestUtils.getLibCPath();
 
diff --git a/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackMixedWithXComp.java b/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackMixedWithXComp.java
index 70a9e67e40601..b264258701dd4 100644
--- a/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackMixedWithXComp.java
+++ b/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackMixedWithXComp.java
@@ -27,14 +27,11 @@
 import java.util.List;
 
 import jdk.test.lib.JDKToolLauncher;
-import jdk.test.lib.Platform;
 import jdk.test.lib.SA.SATestUtils;
 import jdk.test.lib.Utils;
 import jdk.test.lib.apps.LingeredApp;
 import jdk.test.lib.process.OutputAnalyzer;
 
-import jtreg.SkippedException;
-
 /**
  * @test id=xcomp
  * @bug 8370176
@@ -114,10 +111,6 @@ private static void runJstack(LingeredApp app) throws Exception {
     }
 
     public static void main(String... args) throws Exception {
-        if (Platform.isMusl()) {
-            throw new SkippedException("This test does not work on musl libc.");
-        }
-
         SATestUtils.skipIfCannotAttach(); // throws SkippedException if attach not expected to work.
         LingeredApp app = null;
 
diff --git a/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackPrintVMLocks.java b/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackPrintVMLocks.java
index e0774917f8076..c0a6f4faf5415 100644
--- a/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackPrintVMLocks.java
+++ b/test/hotspot/jtreg/serviceability/sa/TestJhsdbJstackPrintVMLocks.java
@@ -22,11 +22,9 @@
  */
 
 import jdk.test.lib.JDKToolLauncher;
-import jdk.test.lib.Platform;
 import jdk.test.lib.SA.SATestUtils;
 import jdk.test.lib.apps.LingeredApp;
 import jdk.test.lib.process.OutputAnalyzer;
-import jtreg.SkippedException;
 
 /**
  * @test
@@ -44,10 +42,6 @@ public class TestJhsdbJstackPrintVMLocks {
 
     final static int MAX_ATTEMPTS = 5;
     public static void main(String[] args) throws Exception {
-        if (Platform.isMusl()) {
-            throw new SkippedException("This test does not work on musl libc.");
-        }
-
         SATestUtils.skipIfCannotAttach(); // throws SkippedException if attach not expected to work.
 
         LingeredApp theApp = null;

From 2dc4f1dfa101f511a0305ede04aed027eb87c1f0 Mon Sep 17 00:00:00 2001
From: Yasumasa Suenaga <yasuenag@gmail.com>
Date: Sun, 19 Apr 2026 17:12:54 +0900
Subject: [PATCH 7/7] Update copyright year

---
 src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.c | 2 +-
 src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.c b/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.c
index ee8db71d754b6..a63e95e439dd9 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.c
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
diff --git a/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.h b/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.h
index a675b6f92e304..d82bf794af262 100644
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.h
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/salibelf.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it