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.
-- v3: 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 | 38 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 40 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..016f1def249 100644 --- a/loader/preloader.c +++ b/loader/preloader.c @@ -1387,6 +1387,32 @@ 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) {} +static struct r_debug_extended r_debug = {.base = {.r_version = 2}}; + +/* 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; + + 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)); + + 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++; + + r_debug.base.r_ldbase = (ElfW(Addr))l_addr; + r_debug.base.r_brk = (ElfW(Addr))_dl_debug_state; + if (dyn->d_tag == DT_DEBUG) dyn->d_un.d_ptr = (uintptr_t)&r_debug; +}
/* * wld_start @@ -1403,6 +1429,7 @@ 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 +1459,8 @@ 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 +1499,15 @@ 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..fdbc1e264cd 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 = {0}; + +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=143087
Your paranoid android.
=== debian11 (build log) ===
../wine/loader/preloader.c:1392:15: error: variable ���r_debug��� has initializer but incomplete type ../wine/loader/preloader.c:1392:44: error: ���struct r_debug_extended��� has no member named ���base��� ../wine/loader/preloader.c:1392:51: error: extra brace group at end of initializer ../wine/loader/preloader.c:1412:12: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1413:12: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1504:31: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1508:47: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1392:32: error: storage size of ���r_debug��� isn���t known Task: The win32 Wine build failed
=== debian11b (build log) ===
../wine/loader/preloader.c:1392:15: error: variable ���r_debug��� has initializer but incomplete type ../wine/loader/preloader.c:1392:44: error: ���struct r_debug_extended��� has no member named ���base��� ../wine/loader/preloader.c:1392:51: error: extra brace group at end of initializer ../wine/loader/preloader.c:1412:12: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1413:12: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1504:31: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1508:47: error: invalid use of undefined type ���struct r_debug_extended��� ../wine/loader/preloader.c:1392:32: error: storage size of ���r_debug��� isn���t known Task: The wow64 Wine build failed
Well there's obviously an issue as it segfaults on Gitlab, but I'm not reproducing it locally.
-
Marvin -
Rémi Bernon -
Rémi Bernon (＠rbernon)