This serie is a first attempt to provide a solution to bug 57308 [1](https://bugs.winehq.org/show_bug.cgi?id=57308).
Basically, Arch distro is looking for Wine support in distributing debug information for Wine PE modules separated from image.
A quick overview of distro (Debian, Fedora, Arch) situation i (I may have missed a couple of items), but:
- no distro ship separate debug information for PE modules (they do it for ELF ones though) - at best, they ship unstripped PE modules.
IMO, we need to help them pave the way to what should be the best expected situation (in Wine and wrt distros) to support separate debug information for PE images.
First, I believe we need to use a (solid) key to bind the stripped image and the file holding the debug information. In ELF format, this is typically done by inserting a .note.gnu.build-id section (in both stripped image and debug information file) which contains the key. This key is used to either search in fixed location (eg /usr/lib/.debug), or as key to download the debug information from a remote server (debuginfod). The key is generally made of a hash of (some sections of) the image file. This allows (esp. in the case of downloading the debug information from a debugger) to discriminate between several versions of the same module.
I think we should target this kind of solution instead of storing the debug information alongside the module (usually done as ntdll.dll.debug). This wouldn't let debuggers download the expected debug info upon request.
Fortunately, gcc and clang provide a build-id option (when generating PE images) which stores this key in the PE image.
What this serie does:
- fixes & improves dbghelp in the support of the build-id information from gcc/mingw & clang, - improves Wine's configure script so that clang can be used to generate dwarf debug information and build-id information in PE builds, - adds a couple of additional search locations for debug information files,
It takes the following assumptions for the storage:
- debug information files for PE images are stored in same hierarchy as debug information files for ELF images (eg /usr/lib/.debug) - naming of such files is done as ELF, ie by using the hex string generated from the binary blob of the key. This is _NOT_ the usual way how the GUID will be printed (because the first 3 integers of the GUID are stored in little-endian format). (Note: I had to make a choice here. I don't have strong arguments one way or the other, but we need to agree on the convention here).
What distro should do to support separate debug info:
- configure Wine with --enable-build-id - adapt at least the packaging tool to extract the key out of unstripped image [2], - if binutils isn't compiled with PE support (this is apparently the Arch case), adapt the scripts to use x86_64-objcopy instead of objcopy (and friends).
I marked this MR as draft for now, as:
- I still need to polish some items (like the default location for looking up debug information files), - wait for feedback on this proposal (it does make a couple of assumptions that need sharing IMO),
Further steps:
- the steps above are mainly targetted to have a solution for packaged download of debug information files, - this should be integrated in debuginfod (server side: ingestion of PE files and client side: ensure gdb, lldb are compatible; implement debuginfod in winedbg).
Feed back welcomed!
[2]:
The least invasive readelf replacement (assuming binutils is compiled with PE support). (otherwise, use x86_64-objdump)
``` BUILDID=`objdump -p "$INPUT" | sed -n "/RSDS signature / {s/.*signature //; s/ age.*//p; q;}"` BUILDID=${BUILDID:6:2}${BUILDID:4:2}${BUILDID:2:2}${BUILDID:0:2}${BUILDID:10:2}${BUILDID:8:2}${BUILDID:14:2}${BUILDID:12:2}${BUILDID:16} ```
Additional note: gcc/mingw puts the desired debug entry inside a dedicated section (.buildid), while clangs keeps it in .rdata (as msvc does). So, this invalidates any attempt to get information from the .buildid section (as stated in bug report).
-- v3: configure.ac: Ensure dwarf debug sections are kept with clang with build-id enabled. dbghelp: Search debug info with buildid for RSDS debug entry w/o filenames. dbghelp: Extend search for buildid in system directories.
From: Eric Pouech epouech@codeweavers.com
Search for files <buildid> and <buildid>.debug Fedora (at least) now put the debug info here (instead of /usr/lib/debug/.build). So search both directories.
Signed-off-by: Eric Pouech epouech@codeweavers.com --- dlls/dbghelp/module.c | 88 +++++++++++++++++++++++-------------------- 1 file changed, 47 insertions(+), 41 deletions(-)
diff --git a/dlls/dbghelp/module.c b/dlls/dbghelp/module.c index 4b4dbbaf595..478017900dd 100644 --- a/dlls/dbghelp/module.c +++ b/dlls/dbghelp/module.c @@ -664,69 +664,75 @@ static WCHAR* append_hex(WCHAR* dst, const BYTE* id, const BYTE* end) return dst; }
-/****************************************************************** - * image_locate_build_id_target - * - * Try to find the .so file containing the debug info out of the build-id note information - */ -static struct image_file_map* image_locate_build_id_target(const BYTE* id, unsigned idlen) +static BOOL image_locate_build_id_target_in_dir(struct image_file_map *fmap_link, const BYTE* id, unsigned idlen, const WCHAR *from) { - struct image_file_map* fmap_link = NULL; - DWORD sz; - WCHAR* p; - WCHAR* z; + size_t from_len = wcslen(from); + BOOL found = FALSE; + WCHAR *p, *z;
- fmap_link = HeapAlloc(GetProcessHeap(), 0, sizeof(*fmap_link)); - if (!fmap_link) return NULL; - - p = malloc(sizeof(L"/usr/lib/debug/.build-id/") + - (idlen * 2 + 1) * sizeof(WCHAR) + sizeof(L".debug")); - if (!p) goto fail; - wcscpy(p, L"/usr/lib/debug/.build-id/"); - z = p + wcslen(p); - if (idlen) + if ((p = malloc((from_len + idlen * 2 + 1) * sizeof(WCHAR) + sizeof(L".debug")))) { + memcpy(p, from, from_len * sizeof(WCHAR)); + z = p + from_len; z = append_hex(z, id, id + 1); if (idlen > 1) { *z++ = L'/'; z = append_hex(z, id + 1, id + idlen); } - } - wcscpy(z, L".debug"); - TRACE("checking %s\n", debugstr_w(p)); + wcscpy(z, L".debug"); + TRACE("checking %s\n", debugstr_w(p)); + found = image_check_debug_link_gnu_id(p, fmap_link, id, idlen);
- if (image_check_debug_link_gnu_id(p, fmap_link, id, idlen)) - { free(p); - return fmap_link; } + return found; +} + +/****************************************************************** + * image_locate_build_id_target + * + * Try to find an image file containing the debug info out of the build-id + * note information. + */ +static struct image_file_map* image_locate_build_id_target(const BYTE* id, unsigned idlen) +{ + struct image_file_map* fmap_link; + DWORD sz; + + if (!idlen) return NULL; + + if (!(fmap_link = HeapAlloc(GetProcessHeap(), 0, sizeof(*fmap_link)))) + return NULL; + if (image_locate_build_id_target_in_dir(fmap_link, id, idlen, L"/usr/lib/debug/.build-id/")) + return fmap_link; + if (image_locate_build_id_target_in_dir(fmap_link, id, idlen, L"/usr/lib/.build-id/")) + return fmap_link;
sz = GetEnvironmentVariableW(L"WINEHOMEDIR", NULL, 0); if (sz) { - z = realloc(p, sz * sizeof(WCHAR) + - sizeof(L"\.cache\debuginfod_client\") + - idlen * 2 * sizeof(WCHAR) + sizeof(L"\debuginfo") + 500); - if (!z) goto fail; - p = z; - GetEnvironmentVariableW(L"WINEHOMEDIR", p, sz); - z = p + sz - 1; - wcscpy(z, L"\.cache\debuginfod_client\"); - z += wcslen(z); - z = append_hex(z, id, id + idlen); - wcscpy(z, L"\debuginfo"); - TRACE("checking %ls\n", p); - if (image_check_debug_link_gnu_id(p, fmap_link, id, idlen)) + WCHAR *p, *z; + p = malloc(sz * sizeof(WCHAR) + + sizeof(L"\.cache\debuginfod_client\") + + idlen * 2 * sizeof(WCHAR) + sizeof(L"\debuginfo") + 500); + if (p && GetEnvironmentVariableW(L"WINEHOMEDIR", p, sz) == sz - 1) { + BOOL found; + + wcscpy(p + sz - 1, L"\.cache\debuginfod_client\"); + z = p + wcslen(p); + z = append_hex(z, id, id + idlen); + wcscpy(z, L"\debuginfo"); + TRACE("checking %ls\n", p); + found = image_check_debug_link_gnu_id(p, fmap_link, id, idlen); free(p); - return fmap_link; + if (found) return fmap_link; } }
TRACE("not found\n"); -fail: - free(p); + HeapFree(GetProcessHeap(), 0, fmap_link); return NULL; }
From: Eric Pouech epouech@codeweavers.com
Signed-off-by: Eric Pouech epouech@codeweavers.com --- dlls/dbghelp/dbghelp_private.h | 2 ++ dlls/dbghelp/module.c | 20 ++++++++++++++++++-- dlls/dbghelp/pe_module.c | 24 ++++++++++++++++++++++++ 3 files changed, 44 insertions(+), 2 deletions(-)
diff --git a/dlls/dbghelp/dbghelp_private.h b/dlls/dbghelp/dbghelp_private.h index d8761bd599a..8def6a7dae6 100644 --- a/dlls/dbghelp/dbghelp_private.h +++ b/dlls/dbghelp/dbghelp_private.h @@ -788,6 +788,8 @@ extern BOOL pe_unmap_directory(struct module* module, int dirno, const c extern DWORD pe_get_file_indexinfo(void* image, DWORD size, SYMSRV_INDEX_INFOW* info); extern const BYTE* pe_lock_region_from_rva(struct module *module, DWORD rva, DWORD size, DWORD *length); extern BOOL pe_unlock_region(struct module *module, const BYTE* region); +struct image_file_map; +extern BOOL pe_has_buildid_debug(struct image_file_map *fmap, GUID *guid);
/* source.c */ extern unsigned source_new(struct module* module, const char* basedir, const char* source); diff --git a/dlls/dbghelp/module.c b/dlls/dbghelp/module.c index 478017900dd..b8848f4010a 100644 --- a/dlls/dbghelp/module.c +++ b/dlls/dbghelp/module.c @@ -527,6 +527,7 @@ static BOOL image_check_debug_link_gnu_id(const WCHAR* file, struct image_file_m { struct image_section_map buildid_sect; DWORD read_bytes; + GUID guid; HANDLE handle; WCHAR *path; WORD magic; @@ -545,6 +546,9 @@ static BOOL image_check_debug_link_gnu_id(const WCHAR* file, struct image_file_m ret = elf_map_handle(handle, fmap); CloseHandle(handle);
+ if (ret && pe_has_buildid_debug(fmap, &guid)) + return TRUE; + if (ret && image_find_section(fmap, ".note.gnu.build-id", &buildid_sect)) { const UINT32* note; @@ -557,12 +561,13 @@ static BOOL image_check_debug_link_gnu_id(const WCHAR* file, struct image_file_m { if (note[1] == idlen && !memcmp(note + 3 + ((note[0] + 3) >> 2), id, idlen)) return TRUE; - WARN("mismatch in buildid information for %s\n", debugstr_w(file)); } } image_unmap_section(&buildid_sect); image_unmap_file(fmap); } + if (ret) + WARN("mismatch in buildid information for %s\n", debugstr_w(file)); return FALSE; }
@@ -844,7 +849,18 @@ BOOL image_check_alternate(struct image_file_map* fmap, const struct module* mod struct image_file_map* fmap_link = NULL;
/* if present, add the .gnu_debuglink file as an alternate to current one */ - if (image_find_section(fmap, ".note.gnu.build-id", &buildid_sect)) + if (fmap->modtype == DMT_PE) + { + GUID guid; + + if (pe_has_buildid_debug(fmap, &guid)) + { + /* reorder bytes to match little endian order */ + fmap_link = image_locate_build_id_target((const BYTE*)&guid, sizeof(guid)); + } + } + /* if present, add the .note.gnu.build-id as an alternate to current one */ + if (!fmap_link && image_find_section(fmap, ".note.gnu.build-id", &buildid_sect)) { const UINT32* note;
diff --git a/dlls/dbghelp/pe_module.c b/dlls/dbghelp/pe_module.c index 75060e2dfa6..bd3d6000535 100644 --- a/dlls/dbghelp/pe_module.c +++ b/dlls/dbghelp/pe_module.c @@ -1036,3 +1036,27 @@ DWORD pe_get_file_indexinfo(void* image, DWORD size, SYMSRV_INDEX_INFOW* info) } return msc_get_file_indexinfo(image, dbg, dirsize / sizeof(*dbg), info); } + +/* check if image contains a debug entry that contains a gcc/mingw - clang build-id information */ +BOOL pe_has_buildid_debug(struct image_file_map *fmap, GUID *guid) +{ + BOOL ret = FALSE; + + if (fmap->modtype == DMT_PE) + { + SYMSRV_INDEX_INFOW info = {.sizeofstruct = sizeof(info)}; + const void *image = pe_map_full(fmap, NULL); + + if (image) + { + DWORD retval = pe_get_file_indexinfo((void*)image, GetFileSize(fmap->u.pe.hMap, NULL), &info); + if ((retval == ERROR_SUCCESS || retval == ERROR_BAD_EXE_FORMAT) && info.age && !info.pdbfile[0]) + { + *guid = info.guid; + ret = TRUE; + } + pe_unmap_full(fmap); + } + } + return ret; +}
From: Eric Pouech epouech@codeweavers.com
Signed-off-by: Eric Pouech epouech@codeweavers.com --- configure.ac | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/configure.ac b/configure.ac index 74fed2f681e..da17838ec4d 100644 --- a/configure.ac +++ b/configure.ac @@ -1004,16 +1004,24 @@ This is an error since --enable-archs=$wine_arch was requested.])]) if test "x$ac_debug_format_seen" = x then case $wine_crossdebug in - *dwarf) WINE_TRY_PE_CFLAGS([-gdwarf-4]) ;; + dnl clang refuses by default to generate the dwarf sections with long names + *dwarf) WINE_TRY_PE_CFLAGS([-gdwarf-4],[AS_VAR_APPEND([${wine_arch}_CFLAGS],[" -gdwarf-4"])], + [WINE_TRY_PE_CFLAGS([-gdwarf-4 -Wl,-debug:dwarf], + [AS_VAR_APPEND([${wine_arch}_CFLAGS],[" -gdwarf-4"]) + AS_VAR_APPEND([${wine_arch}_LDFLAGS],[" -Wl,-debug:dwarf"])])]) ;; pdb) WINE_TRY_PE_CFLAGS([-gcodeview]) ;; esac fi AS_VAR_SET([${wine_arch}_DEBUG],[$wine_crossdebug])
test "x$enable_werror" != xyes || WINE_TRY_PE_CFLAGS([-Werror]) + dnl gcc/mingw uses --build-id, while clang uses -build-id test "x$enable_build_id" != xyes || WINE_TRY_PE_CFLAGS([-Wl,--build-id], - [AS_VAR_APPEND([${wine_arch}_CFLAGS],[" -Wl,--build-id"]) - AS_VAR_APPEND([${wine_arch}_LDFLAGS],[" -Wl,--build-id"])]) + [AS_VAR_APPEND([${wine_arch}_CFLAGS],[" -Wl,--build-id"]) + AS_VAR_APPEND([${wine_arch}_LDFLAGS],[" -Wl,--build-id"])], + [WINE_TRY_PE_CFLAGS([-Wl,-build-id], + [AS_VAR_APPEND([${wine_arch}_CFLAGS],[" -Wl,-build-id"]) + AS_VAR_APPEND([${wine_arch}_LDFLAGS],[" -Wl,-build-id"])])])
done
On Sat Nov 23 15:16:39 2024 +0000, Chih-Hsuan Yen wrote:
But I can't repro here. Could you share your configure options? Maybe
I didn't retest with your combination. Regarding the issue with `-g` and `-gdwarf-4`, I can still reproduce with the AUR package wine-git (see [PKGBUILD](https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=wine-git#n109) for configure options). I can see mingw compilers are invoked with `-g` instead of `-gdwarf-4` in build logs. Complete logs: [wine-git-9.22.r0.g51ccd95c49c-1-x86_64-build.log.gz](/uploads/827938ba7eacbec7d561b0d25ff74163/wine-git-9.22.r0.g51ccd95c49c-1-x86_64-build.log.gz) Here the wine-git package undergoes similar modifications below, while without `-g` -> `-gdwarf-4` changes.
dbghelp (with this MR) searches both /usr/lib/debug/.build-id/xxx/yyy
and /usr/lib/debug/.build-id/xxx/yyy.debug so something else must be going wrong. It seems dbghelp stops after it doesn't find debug symbols in /usr/lib/debug/.build-id/xxx/yyy. I ran a test program which crashes in msvcrt.exe and got:
017c:trace:dbghelp:image_locate_build_id_target_in_dir checking L"/usr/lib/debug/.build-id/b7/7e9f19b7d1e8f889b2b790d6116a1d" 017c:trace:dbghelp:image_check_debug_link_gnu_id Located debug information file at L"/usr/lib/debug/.build-id/b7/7e9f19b7d1e8f889b2b790d6116a1d" 017c:trace:dbghelp:pe_load_stabs failed to load the STABS debug info 017c:trace:dbghelp_dwarf:dwarf2_parse Loading Dwarf2 information for L"msvcrt" 017c:trace:dbghelp:image_load_debugaltlink No .gnu_debugaltlink section found for L"msvcrt" 017c:trace:dbghelp:pe_load_dwarf successfully loaded the DWARF debug infoHere /usr/lib/debug/.build-id/b7/7e9f19b7d1e8f889b2b790d6116a1d points to /usr/lib/wine/x86_64-windows/msvcrt.dll. Complete wine logs: [winedbg.log](/uploads/5b93c494acfd801b282b8cae3cb0154b/winedbg.log) Test program: [test-debugging-symbols.c](/uploads/cc7979fadadec245c548b49355106383/test-debugging-symbols.c) Here wine is built using wine-git AUR package with the following modifications:
diff --git a/PKGBUILD b/PKGBUILD index e679471..ccdf826 100644 --- a/PKGBUILD +++ b/PKGBUILD @@ -88,6 +88,15 @@ sha256sums=('SKIP' prepare() { rm -rf build-{32,64} mkdir -p build-{32,64} + + cd wine + + # https://gitlab.winehq.org/wine/wine/-/merge_requests/6715 + git cherry-pick -n 3e0eda8986172fe77c3f871100d46f62c9fcd2d6 + git cherry-pick -n 4fb40e04a6d41508beb53a70a70470cc1102a863 + git cherry-pick -n 8283999ec06e5cd8af5fd4fdf6d29765571c6f63 + + autoreconf -ifv } pkgver() { @@ -98,8 +107,8 @@ build() { export CFLAGS+=' -ffat-lto-objects' # apply flags for cross-compilation - export CROSSCFLAGS="${CFLAGS/-Werror=format-security/} -g" - export CROSSCXXFLAGS="${CXXFLAGS/-Werror=format-security/} -g" + export CROSSCFLAGS="${CFLAGS/-Werror=format-security/} -gdwarf-4" + export CROSSCXXFLAGS="${CXXFLAGS/-Werror=format-security/} -gdwarf-4" export CROSSLDFLAGS="${LDFLAGS//-Wl,-z*([^[:space:]])/}" # build wine 64-bit @@ -112,6 +121,7 @@ build() { --with-x \ --with-wayland \ --with-gstreamer \ + --enable-build-id \ --enable-win64 make @@ -125,6 +135,7 @@ build() { --with-x \ --with-wayland \ --with-gstreamer \ + --enable-build-id \ --with-wine64="${srcdir}/build-64" make }
thanks for taking the time to retest
Regarding the issue with `-g` and `-gdwarf-4`, I can still reproduce with the AUR package wine-git (see [PKGBUILD](https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=wine-git#n109) for configure options). I can see mingw compilers are invoked with `-g` instead of `-gdwarf-4` in build logs.
updated the MR, hopefully this should work now
It seems dbghelp stops after it doesn't find debug symbols in /usr/lib/debug/.build-id/xxx/yyy. I ran a test program which crashes in msvcrt.exe and got:
it's likely we shouldn't try `/usr/lib/debug/.build-id/xxx/yyy` (which points to the stripped image) but `/usr/lib/debug/.build-id/xxx/yyy.debug` instead. (updated MR to only try the later, previously was trying the former first, and in case of failure the later)
Side note: looks like your test program is not compiled in dwarf-4 (but that shouldn't matter for getting the right information for the rest of the backtrace)
017c:trace:dbghelp_dwarf:dwarf2_parse Loading Dwarf2 information for L"test-debugging-symbols" 017c:trace:dbghelp:image_load_debugaltlink No .gnu_debugaltlink section found for L"test-debugging-symbols" 017c:trace:dbghelp_dwarf:dwarf2_parse_compilation_unit_head Compilation Unit Header found at 0x0: 017c:trace:dbghelp_dwarf:dwarf2_parse_compilation_unit_head - length: 9868 017c:trace:dbghelp_dwarf:dwarf2_parse_compilation_unit_head - version: 5 017c:trace:dbghelp_dwarf:dwarf2_parse_compilation_unit_head - abbrev_offset: 2049 017c:trace:dbghelp_dwarf:dwarf2_parse_compilation_unit_head - word_size: 0 017c:trace:dbghelp_dwarf:dwarf2_parse_compilation_unit_head - offset_size: 4
and there's a crash when quitting the debugger
V3 pushed:
* amended search logic in /usr/lib/debug/.build-id * amended clang configuration
Jacek Caban (@jacek) commented about configure.ac:
if test "x$ac_debug_format_seen" = x then case $wine_crossdebug in
*dwarf) WINE_TRY_PE_CFLAGS([-gdwarf-4]) ;;
dnl clang refuses by default to generate the dwarf sections with long names*dwarf) WINE_TRY_PE_CFLAGS([-gdwarf-4],[AS_VAR_APPEND([${wine_arch}_CFLAGS],[" -gdwarf-4"])],[WINE_TRY_PE_CFLAGS([-gdwarf-4 -Wl,-debug:dwarf],[AS_VAR_APPEND([${wine_arch}_CFLAGS],[" -gdwarf-4"])AS_VAR_APPEND([${wine_arch}_LDFLAGS],[" -Wl,-debug:dwarf"])])]) ;;
This looks more complicated than it needs to be, how about checking just `-Wl,-debug:dwarf` first: ``` WINE_TRY_PE_CFLAGS([-Wl,-debug:dwarf],[AS_VAR_APPEND([${wine_arch}_LDFLAGS],[" -Wl,-debug:dwarf"]) CFLAGS="$CFLAGS -Wl,-debug:dwarf"]) WINE_TRY_PE_CFLAGS([-gdwarf-4]) ```
Jacek Caban (@jacek) commented about configure.ac:
AS_VAR_APPEND([${wine_arch}_LDFLAGS],[" -Wl,-debug:dwarf"])])]) ;; pdb) WINE_TRY_PE_CFLAGS([-gcodeview]) ;; esacfi AS_VAR_SET([${wine_arch}_DEBUG],[$wine_crossdebug])
test "x$enable_werror" != xyes || WINE_TRY_PE_CFLAGS([-Werror])
dnl gcc/mingw uses --build-id, while clang uses -build-id test "x$enable_build_id" != xyes || WINE_TRY_PE_CFLAGS([-Wl,--build-id],
[AS_VAR_APPEND([${wine_arch}_CFLAGS],[" -Wl,--build-id"])AS_VAR_APPEND([${wine_arch}_LDFLAGS],[" -Wl,--build-id"])])
[AS_VAR_APPEND([${wine_arch}_CFLAGS],[" -Wl,--build-id"])AS_VAR_APPEND([${wine_arch}_LDFLAGS],[" -Wl,--build-id"])],[WINE_TRY_PE_CFLAGS([-Wl,-build-id],[AS_VAR_APPEND([${wine_arch}_CFLAGS],[" -Wl,-build-id"])AS_VAR_APPEND([${wine_arch}_LDFLAGS],[" -Wl,-build-id"])])])
It looks like a job for winegcc, it could understand `-Wl,--build-id` and use its correct form depending on the target.
updated the MR, hopefully this should work now
Yes, it works now.
it's likely we shouldn't try `/usr/lib/debug/.build-id/xxx/yyy` (which points to the stripped image) but `/usr/lib/debug/.build-id/xxx/yyy.debug` instead. (updated MR to only try the later, previously was trying the former first, and in case of failure the later)
Thanks for the change. Now debugging symbols are correctly loaded.
-
Chih-Hsuan Yen (＠yan12125) -
Eric Pouech
-
eric pouech (＠epo)
-
Jacek Caban (＠jacek)