gh-137293 Clear exceptions before search_elf_file_for_section

Author: uxioandrade

Python/remote_debug.h

@@ -572,23 +572,35 @@ search_elf_file_for_section(
 
     int fd = open(elf_file, O_RDONLY);
     if (fd < 0) {
+        PyErr_Format(PyExc_OSError,
+            "Cannot open ELF file '%s' for section '%s' search: %s",
+            elf_file, secname, strerror(errno));
         goto exit;
     }
 
     struct stat file_stats;
     if (fstat(fd, &file_stats) != 0) {
+        PyErr_Format(PyExc_OSError,
+            "Cannot get file size for ELF file '%s' during section '%s' search: %s",
+            elf_file, secname, strerror(errno));
         goto exit;
     }
 
     file_memory = mmap(NULL, file_stats.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
     if (file_memory == MAP_FAILED) {
+        PyErr_Format(PyExc_OSError,
+            "Cannot memory map ELF file '%s' (size: %lld bytes) for section '%s' search: %s",
+            elf_file, (long long)file_stats.st_size, secname, strerror(errno));
         goto exit;
     }
 
     Elf_Ehdr* elf_header = (Elf_Ehdr*)file_memory;
 
     // Validate ELF header
     if (elf_header->e_shstrndx >= elf_header->e_shnum) {
+        PyErr_Format(PyExc_RuntimeError,
+            "Invalid ELF file '%s': string table index %u >= section count %u",
+            elf_file, elf_header->e_shstrndx, elf_header->e_shnum);
         goto exit;
     }
 
@@ -623,6 +635,9 @@ search_elf_file_for_section(
     }
 
     if (first_load_segment == NULL) {
+        PyErr_Format(PyExc_RuntimeError,
+            "No PT_LOAD segment found in ELF file '%s' (%u program headers examined)",
+            elf_file, elf_header->e_phnum);
         goto exit;
     }
 
@@ -635,6 +650,9 @@ search_elf_file_for_section(
         munmap(file_memory, file_stats.st_size);
     }
     if (fd >= 0 && close(fd) != 0) {
+        PyErr_Format(PyExc_OSError,
+            "Failed to close ELF file '%s': %s",
+            elf_file, strerror(errno));
         result = 0;
     }
     return result;
@@ -710,6 +728,7 @@ search_linux_map_for_section(proc_handle_t *handle, const char* secname, const c
         }
 
         if (strstr(filename, substr)) {
+            PyErr_Clear();
             retval = search_elf_file_for_section(handle, secname, start, path);
             if (retval) {
                 break;