Effectively implementing the debugger interface as described in https://sourceware.org/git/?p=glibc.git;a=blob;f=elf/rtld-debugger-interface...
This is an actual attempt at having this upstream, split from https://gitlab.winehq.org/wine/wine/-/merge_requests/1074 which people have been finding useful for debugging Wine directly in GDB. This supports everything you would expect, from automatic symbol loading as well as cross-syscall backtraces with the new Python unwinder.
-- v4: ntdll: Maintain a PE module link map and expose it to GDB. loader: Expose the standard debugging symbols for GDB.
From: Rémi Bernon rbernon@codeweavers.com
--- loader/main.c | 3 ++- loader/preloader.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 45 insertions(+), 1 deletion(-)
diff --git a/loader/main.c b/loader/main.c index c258e025183..5a208cc048c 100644 --- a/loader/main.c +++ b/loader/main.c @@ -38,7 +38,8 @@
extern char **environ;
-/* the preloader will set this variable */ +/* the preloader will set these variables */ +__attribute((visibility("default"))) struct r_debug *wine_r_debug = NULL; const __attribute((visibility("default"))) struct wine_preload_info *wine_main_preload_info = NULL;
/* canonicalize path and return its directory name */ diff --git a/loader/preloader.c b/loader/preloader.c index d0551bae63a..776f593608d 100644 --- a/loader/preloader.c +++ b/loader/preloader.c @@ -79,12 +79,16 @@ #ifdef HAVE_ELF_H # include <elf.h> #endif + +/* define _r_debug so we can re-define it as r_debug_extended */ +#define _r_debug no_r_debug; #ifdef HAVE_LINK_H # include <link.h> #endif #ifdef HAVE_SYS_LINK_H # include <sys/link.h> #endif +#undef _r_debug
#include "wine/asm.h" #include "main.h" @@ -1387,6 +1391,33 @@ static void set_process_name( int argc, char *argv[] ) for (i = 1; i < argc; i++) argv[i] -= off; }
+/* GDB integration, _dl_debug_state is *required* for GDB to hook the preloader */ +__attribute((visibility("default"))) void _dl_debug_state(void) {} +__attribute((visibility("default"))) struct r_debug_extended _r_debug = {{0}}; + +/* sets the preloader r_debug address into DT_DEBUG */ +static void init_r_debug( struct wld_auxv *av ) +{ + ElfW(Phdr) *phdr, *ph; + ElfW(Dyn) *dyn = NULL; + char *l_addr; + int phnum; + + _r_debug.base.r_version = 2; + _r_debug.base.r_brk = (ElfW(Addr))_dl_debug_state; + + if (!(phnum = get_auxiliary( av, AT_PHNUM, 0 ))) return; + if (!(phdr = (void *)get_auxiliary( av, AT_PHDR, 0 ))) return; + l_addr = (char *)phdr - sizeof(ElfW(Ehdr)); + _r_debug.base.r_ldbase = (ElfW(Addr))l_addr; + + for (ph = phdr; ph < &phdr[phnum]; ++ph) if (ph->p_type == PT_DYNAMIC) break; + if (ph >= &phdr[phnum]) return; + + dyn = (void *)(ph->p_vaddr + l_addr); + while (dyn->d_tag != DT_DEBUG && dyn->d_tag != DT_NULL) dyn++; + if (dyn->d_tag == DT_DEBUG) dyn->d_un.d_ptr = (uintptr_t)&_r_debug; +}
/* * wld_start @@ -1403,6 +1434,7 @@ void* wld_start( void **stack ) struct wld_auxv new_av[8], delete_av[3], *av; struct wld_link_map main_binary_map, ld_so_map; struct wine_preload_info **wine_main_preload_info; + struct r_debug *ld_so_r_debug, **wine_r_debug;
pargc = *stack; argv = (char **)pargc + 1; @@ -1432,6 +1464,8 @@ void* wld_start( void **stack ) dump_auxiliary( av ); #endif
+ init_r_debug( av ); + /* reserve memory that Wine needs */ if (reserve) preload_reserve( reserve ); for (i = 0; preload_info[i].size; i++) @@ -1470,6 +1504,15 @@ void* wld_start( void **stack ) interp = (char *)main_binary_map.l_addr + main_binary_map.l_interp; map_so_lib( interp, &ld_so_map );
+ /* expose ld.so _r_debug as a separate namespace in r_next */ + ld_so_r_debug = find_symbol( &ld_so_map, "_r_debug", STT_OBJECT ); + if (ld_so_r_debug) _r_debug.r_next = (struct r_debug_extended *)ld_so_r_debug; + else wld_printf( "_r_debug not found in ld.so\n" ); + + wine_r_debug = find_symbol( &main_binary_map, "wine_r_debug", STT_OBJECT ); + if (wine_r_debug) *wine_r_debug = &_r_debug.base; + else wld_printf( "wine_r_debug not found\n" ); + /* store pointer to the preload info into the appropriate main binary variable */ wine_main_preload_info = find_symbol( &main_binary_map, "wine_main_preload_info", STT_OBJECT ); if (wine_main_preload_info) *wine_main_preload_info = preload_info;
From: Rémi Bernon rbernon@codeweavers.com
--- dlls/ntdll/unix/virtual.c | 124 +++++++++++++++++++++++++++++++++++++- 1 file changed, 123 insertions(+), 1 deletion(-)
diff --git a/dlls/ntdll/unix/virtual.c b/dlls/ntdll/unix/virtual.c index 02c0bebe879..e32d4bd6677 100644 --- a/dlls/ntdll/unix/virtual.c +++ b/dlls/ntdll/unix/virtual.c @@ -51,6 +51,12 @@ #ifdef HAVE_SYS_USER_H # include <sys/user.h> #endif +#ifdef HAVE_LINK_H +# include <link.h> +#endif +#ifdef HAVE_SYS_LINK_H +# include <sys/link.h> +#endif #ifdef HAVE_LIBPROCSTAT_H # include <libprocstat.h> #endif @@ -79,6 +85,114 @@ WINE_DEFAULT_DEBUG_CHANNEL(virtual); WINE_DECLARE_DEBUG_CHANNEL(module); WINE_DECLARE_DEBUG_CHANNEL(virtual_ranges);
+/* Gdb integration, in loader/main.c */ +static struct r_debug *wine_r_debug; + +#if defined(HAVE_LINK_H) || defined(HAVE_SYS_LINK_H) + +struct link_map_entry +{ + struct link_map map; + const void *module; +}; +static struct link_map link_map = {.l_name = (char *)""}; + +static void r_debug_set_state( int state ) +{ + wine_r_debug->r_map = &link_map; + wine_r_debug->r_state = state; + ((void (*)(void))wine_r_debug->r_brk)(); +} + +static char *r_debug_realpath( const char *path ) +{ + char *real; + if (!path) return NULL; + if (!(real = realpath( path, NULL ))) return strdup( path ); + return real; +} + +static void r_debug_add_module( void *module, const WCHAR *filename, INT_PTR offset ) +{ + UNICODE_STRING redir, nt_name; + OBJECT_ATTRIBUTES attr; + char *unix_path = NULL; + + if (!wine_r_debug) return; + + RtlInitUnicodeString( &nt_name, filename ); + InitializeObjectAttributes( &attr, &nt_name, OBJ_CASE_INSENSITIVE, 0, 0 ); + get_redirect( &attr, &redir ); + + if (!nt_to_unix_file_name( &attr, &unix_path, FILE_OPEN )) + { + struct link_map *ptr = link_map.l_next, *next; + struct link_map_entry *entry; + + while (ptr) + { + entry = LIST_ENTRY(ptr, struct link_map_entry, map); + if (entry->module == module) break; + ptr = ptr->l_next; + } + + r_debug_set_state( RT_ADD ); + + if (ptr) entry->map.l_addr = offset; + else if ((entry = calloc( 1, sizeof(*entry) ))) + { + entry->module = module; + entry->map.l_addr = offset; + entry->map.l_name = r_debug_realpath( unix_path ); + + entry->map.l_next = link_map.l_next; + if ((next = entry->map.l_next)) next->l_prev = &entry->map; + entry->map.l_prev = &link_map; + link_map.l_next = &entry->map; + } + + r_debug_set_state( RT_CONSISTENT ); + } + + free( redir.Buffer ); + free( unix_path ); +} + +static void r_debug_remove_module( void *module ) +{ + struct link_map *ptr = link_map.l_next, *next; + struct link_map_entry *entry; + + if (!wine_r_debug) return; + + while (ptr) + { + entry = LIST_ENTRY(ptr, struct link_map_entry, map); + if (entry->module == module) break; + ptr = ptr->l_next; + } + if (!ptr) return; + + r_debug_set_state( RT_DELETE ); + + entry->map.l_prev->l_next = entry->map.l_next; + if ((next = entry->map.l_next)) next->l_prev = entry->map.l_prev; + + r_debug_set_state( RT_CONSISTENT ); + + free( entry->map.l_name ); + free( entry ); +} + +#else /* defined(HAVE_LINK_H) || defined(HAVE_SYS_LINK_H) */ + +#define RT_CONSISTENT 0 +static void r_debug_set_state( int state ) {} +static void r_debug_add_module( void *module, const WCHAR *filename, INT_PTR offset ) {} +static void r_debug_remove_module( void *module ) {} + +#endif /* defined(HAVE_LINK_H) || defined(HAVE_SYS_LINK_H) */ + struct preload_info { void *addr; @@ -2924,6 +3038,7 @@ static NTSTATUS map_image_into_view( struct file_view *view, const WCHAR *filena #ifdef VALGRIND_LOAD_PDB_DEBUGINFO VALGRIND_LOAD_PDB_DEBUGINFO(fd, ptr, total_size, ptr - (char *)wine_server_get_ptr( image_info->base )); #endif + r_debug_add_module( ptr, filename, ptr - (char *)wine_server_get_ptr( image_info->base ) ); return STATUS_SUCCESS; }
@@ -3279,11 +3394,14 @@ static void *alloc_virtual_heap( SIZE_T size ) void virtual_init(void) { const struct preload_info **preload_info = dlsym( RTLD_DEFAULT, "wine_main_preload_info" ); + struct r_debug **r_debug = dlsym( RTLD_DEFAULT, "wine_r_debug" ); const char *preload = getenv( "WINEPRELOADRESERVE" ); size_t size; int i; pthread_mutexattr_t attr;
+ if (r_debug && (wine_r_debug = *r_debug)) r_debug_set_state( RT_CONSISTENT ); + pthread_mutexattr_init( &attr ); pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE ); pthread_mutex_init( &virtual_mutex, &attr ); @@ -5641,7 +5759,11 @@ static NTSTATUS unmap_view_of_section( HANDLE process, PVOID addr, ULONG flags ) SERVER_END_REQ; if (!status) { - if (view->protect & SEC_IMAGE) release_builtin_module( view->base ); + if (view->protect & SEC_IMAGE) + { + r_debug_remove_module( view->base ); + release_builtin_module( view->base ); + } if (flags & MEM_PRESERVE_PLACEHOLDER) free_pages_preserve_placeholder( view, view->base, view->size ); else delete_view( view ); }
Hi,
It looks like your patch introduced the new failures shown below. Please investigate and fix them before resubmitting your patch. If they are not new, fixing them anyway would help a lot. Otherwise please ask for the known failures list to be updated.
The full results can be found at: https://testbot.winehq.org/JobDetails.pl?Key=143093
Your paranoid android.
=== debian11 (build log) ===
../wine/loader/preloader.c:1396:45: error: variable ���_r_debug��� has initializer but incomplete type ../wine/loader/preloader.c:1396:74: error: extra brace group at end of initializer ../wine/loader/preloader.c:1406:13: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1407:13: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1412:13: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1509:32: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1513:48: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1396:62: error: storage size of ���_r_debug��� isn���t known Task: The win32 Wine build failed
=== debian11b (build log) ===
../wine/loader/preloader.c:1396:45: error: variable ���_r_debug��� has initializer but incomplete type ../wine/loader/preloader.c:1396:74: error: extra brace group at end of initializer ../wine/loader/preloader.c:1406:13: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1407:13: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1412:13: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1509:32: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1513:48: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1396:62: error: storage size of ���_r_debug��� isn���t known Task: The wow64 Wine build failed
The segfaults should be fixed now, was happening because `init_r_debug` was returning early and before having set the `r_brk` address.
On Wed Feb 14 11:09:49 2024 +0000, Rémi Bernon wrote:
I don't know, I don't think this MR does anything special here, and it simply exposes whichever PE file is mapped to Gdb.
Well, so far the filename was never used for anything except for debug logs, so it didn't matter yet.
But when loading `c:\users\fabian\Temp\IXP010.TMP\ADVPACK.DLL`, wine will load the builtin DLL instead, which has a different path. But you'd still pass GDB the filename `c:\users\fabian\Temp\IXP010.TMP\ADVPACK.DLL`, which is wrong.
I'm pretty sure this is the issue with the breakpoints as well (my other comment), since GDB loads data from the dlls inside `c:\windows\system32` instead of my build folder.
GDB should be passed the path of the actual loaded DLL, not the one that the the apps see. Since Alexandre said we can't expose that real path to apps though, you have to get it a different way. For example see https://gitlab.winehq.org/DarkShadow44/wine/-/commit/ef8888b33622adcc3823665..., this fixes the issues I encountered. Not guaranteeing correctness or anything, it's more a POC.
-
Fabian Maurer (＠DarkShadow44) -
Marvin -
Rémi Bernon
-
Rémi Bernon (＠rbernon)