diff options
author | Josh Kunz <jkz@google.com> | 2019-08-16 16:34:22 -0700 |
---|---|---|
committer | Laurent Vivier <laurent@vivier.eu> | 2019-09-11 08:46:52 +0200 |
commit | dc12567a53c88d7a91b9d71db3775782c7f35c84 (patch) | |
tree | 67a0c2b6e805448a0c6aaa16e9c8bf8bd775f636 | |
parent | 0b689da375a689efe04ad8381f607d1292471d96 (diff) |
linux-user: Support gdb 'qOffsets' query for ELF
This is needed to support debugging PIE ELF binaries running under QEMU
user mode. Currently, `code_offset` and `data_offset` remain unset for
all ELF binaries, so GDB is unable to correctly locate the position of
the binary's text and data.
The fields `code_offset`, and `data_offset` were originally added way
back in 2006 to support debugging of bFMT executables (978efd6aac6),
and support was just never added for ELF. Since non-PIE binaries are
loaded at exactly the address specified in the binary, GDB does not need
to relocate any symbols, so the buggy behavior is not normally observed.
http://sourceware.org/gdb/onlinedocs/gdb/General-Query-Packets.html#index-qOffsets-packet
Buglink: https://bugs.launchpad.net/qemu/+bug/1528239
Signed-off-by: Josh Kunz <jkz@google.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190816233422.16715-1-jkz@google.com>
[lv: added link to documentation]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
-rw-r--r-- | linux-user/elfload.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 43c16a846d..f6693e5760 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -2403,6 +2403,8 @@ static void load_elf_image(const char *image_name, int image_fd, } info->load_bias = load_bias; + info->code_offset = load_bias; + info->data_offset = load_bias; info->load_addr = load_addr; info->entry = ehdr->e_entry + load_bias; info->start_code = -1; |