[PATCH 4/4] Add handling for 64-bit module addresses in Cygwin core dumps

Jon Turney
2020-08-12T19:18:50Z

gdb/ChangeLog:

2020-07-01 Jon Turney <jon.turney@dronecode.org.uk>

* windows-tdep.c (NOTE_INFO_MODULE, NOTE_INFO_MODULE64): Define.
(core_process_module_section): Handle NOTE_INFO_MODULE64.
---
gdb/ChangeLog | 5 +++++
gdb/windows-tdep.c | 30 +++++++++++++++++++++++-------
2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/gdb/windows-tdep.c b/gdb/windows-tdep.c
index 037958a4bf5..dd5f69a9acd 100644
--- a/gdb/windows-tdep.c
+++ b/gdb/windows-tdep.c
@@ -105,6 +105,10 @@ enum
CYGWIN_SIGUSR2 = 31,
};

+/* These constants are defined by Cygwin's core_dump.h */
+static constexpr unsigned int NOTE_INFO_MODULE = 3;
+static constexpr unsigned int NOTE_INFO_MODULE64 = 4;
+
struct cmd_list_element *info_w32_cmdlist;

typedef struct thread_information_block_32
@@ -1101,8 +1105,10 @@ core_process_module_section (bfd *abfd, asection *sect, void *obj)
struct cpms_data *data = (struct cpms_data *) obj;
enum bfd_endian byte_order = gdbarch_byte_order (data->gdbarch);

+ unsigned int data_type;
char *module_name;
size_t module_name_size;
+ size_t module_name_offset;
CORE_ADDR base_addr;

gdb_byte *buf = NULL;
@@ -1123,16 +1129,26 @@ core_process_module_section (bfd *abfd, asection *sect, void *obj)

/* A DWORD (data_type) followed by struct windows_core_module_info. */
+ data_type = extract_unsigned_integer (buf, 4, byte_order);

- base_addr =
- extract_unsigned_integer (buf + 4, 4, byte_order);
-
- module_name_size =
- extract_unsigned_integer (buf + 8, 4, byte_order);
+ if (data_type == NOTE_INFO_MODULE)
+ {
+ base_addr = extract_unsigned_integer (buf + 4, 4, byte_order);
+ module_name_size = extract_unsigned_integer (buf + 8, 4, byte_order);
+ module_name_offset = 12;
+ }
+ else if (data_type == NOTE_INFO_MODULE64)
+ {
+ base_addr = extract_unsigned_integer (buf + 4, 8, byte_order);
+ module_name_size = extract_unsigned_integer (buf + 12, 4, byte_order);
+ module_name_offset = 16;
+ }
+ else
+ goto out;

- if (12 + module_name_size > bfd_section_size (sect))
+ if (module_name_offset + module_name_size > bfd_section_size (sect))
goto out;
- module_name = (char *) buf + 12;
+ module_name = (char *) buf + module_name_offset;

/* The first module is the .exe itself. */
if (data->module_count != 0)
--
2.28.0