From 17d347bd607fbc7f3b9d04058b3eb3ca7de1cbc4 Mon Sep 17 00:00:00 2001 From: Peter Schauer Date: Thu, 3 Nov 1994 09:27:23 +0000 Subject: [PATCH] * osfsolib.c (solib_map_sections, first_link_map_member, next_link_map_member, xfer_link_map_member): Retrieve and use shared library relocation offset from runtime loader structures. Use libxproc.a routines to get a working version if USE_LDR_ROUTINES is defined. * README: Remove item about shared library relocation for Alpha OSF/1. --- gdb/ChangeLog | 10 +++ gdb/osfsolib.c | 170 +++++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 159 insertions(+), 21 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 68540bb306..539c53a6ff 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,13 @@ +Thu Nov 3 01:23:45 1994 Peter Schauer (pes@regent.e-technik.tu-muenchen.de) + + * osfsolib.c (solib_map_sections, first_link_map_member, + next_link_map_member, xfer_link_map_member): Retrieve and use + shared library relocation offset from runtime loader structures. + Use libxproc.a routines to get a working version if + USE_LDR_ROUTINES is defined. + * README: Remove item about shared library relocation for + Alpha OSF/1. + Wed Nov 2 15:05:39 1994 Kung Hsu (kung@mexican.cygnus.com) * c-exp.y (yylex): scan template names, and scan nested class diff --git a/gdb/osfsolib.c b/gdb/osfsolib.c index b7bb7aae74..017d4a99c4 100644 --- a/gdb/osfsolib.c +++ b/gdb/osfsolib.c @@ -39,26 +39,58 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "inferior.h" #include "language.h" -#define MAX_PATH_SIZE 256 /* FIXME: Should be dynamic */ +#define MAX_PATH_SIZE 1024 /* FIXME: Should be dynamic */ -/* FIXME: This is a terrible hack for shared library support under OSF/1. - The main problem is that the needed definitions are not contained in - the system header files. - The ldr_* routines described in loader(3) would be the way to go here. - But they do not work for arbitrary target processes (as documented). */ +/* When handling shared libraries, GDB has to find out the pathnames + of all shared libraries that are currently loaded (to read in their + symbols) and where the shared libraries are loaded in memory + (to relocate them properly from their prelinked addresses to the + current load address). + + Under OSF/1 there are two possibilities to get at this information: + 1) Peek around in the runtime loader structures. + These are not documented, and they are not defined in the system + header files. The definitions below were obtained by experimentation, + but they seem stable enough. + 2) Use the undocumented libxproc.a library, which contains the + equivalent ldr_* routines. + This approach is somewhat cleaner, but it requires that the GDB + executable is dynamically linked. In addition it requires a + NAT_CLIBS= -lxproc -Wl,-expect_unresolved,ldr_process_context + linker specification for GDB and all applications that are using + libgdb. + We will use the peeking approach until it becomes unwieldy. */ #ifndef USE_LDR_ROUTINES + +/* Definition of runtime loader structures, found by experimentation. */ #define RLD_CONTEXT_ADDRESS 0x3ffc0000000 typedef struct { CORE_ADDR next; CORE_ADDR previous; - CORE_ADDR unknown; + CORE_ADDR unknown1; char *module_name; CORE_ADDR modinfo_addr; + long module_id; + CORE_ADDR unknown2; + CORE_ADDR unknown3; + long region_count; + CORE_ADDR regioninfo_addr; } ldr_module_info_t; +typedef struct +{ + long unknown1; + CORE_ADDR regionname_addr; + long protection; + CORE_ADDR vaddr; + CORE_ADDR mapaddr; + long size; + long unknown2[5]; +} ldr_region_info_t; + typedef struct { CORE_ADDR unknown1; @@ -68,20 +100,53 @@ typedef struct } ldr_context_t; static ldr_context_t ldr_context; + #else + #include +static ldr_process_t fake_ldr_process; + +/* Called by ldr_* routines to read memory from the current target. */ + +static int ldr_read_memory PARAMS ((CORE_ADDR, char *, int, int)); + +static int +ldr_read_memory (memaddr, myaddr, len, readstring) + CORE_ADDR memaddr; + char *myaddr; + int len; + int readstring; +{ + int result; + char *buffer; + + if (readstring) + { + target_read_string (memaddr, &buffer, len, &result); + if (result == 0) + strcpy (myaddr, buffer); + free (buffer); + } + else + result = target_read_memory (memaddr, myaddr, len); + + if (result != 0) + result = -result; + return result; +} + #endif /* Define our own link_map structure. This will help to share code with solib.c. */ struct link_map { - CORE_ADDR l_addr; /* address at which object mapped */ + CORE_ADDR l_offset; /* prelink to load address offset */ char *l_name; /* full name of loaded object */ ldr_module_info_t module_info; /* corresponding module info */ }; -#define LM_ADDR(so) ((so) -> lm.l_addr) +#define LM_OFFSET(so) ((so) -> lm.l_offset) #define LM_NAME(so) ((so) -> lm.l_name) struct so_list { @@ -209,10 +274,10 @@ solib_map_sections (so) for (p = so -> sections; p < so -> sections_end; p++) { /* Relocate the section binding addresses as recorded in the shared - object's file by the base address to which the object was actually - mapped. */ - p -> addr += (CORE_ADDR) LM_ADDR (so); - p -> endaddr += (CORE_ADDR) LM_ADDR (so); + object's file by the offset to get the address to which the + object was actually mapped. */ + p -> addr += LM_OFFSET (so); + p -> endaddr += LM_OFFSET (so); so -> lmend = (CORE_ADDR) max (p -> endaddr, so -> lmend); if (STREQ (p -> the_bfd_section -> name, ".text")) { @@ -251,9 +316,13 @@ first_link_map_member () ldr_module_t mod_id = LDR_NULL_MODULE; size_t retsize; - if (ldr_next_module(inferior_pid, &mod_id) != 0 + fake_ldr_process = ldr_core_process (); + ldr_set_core_reader (ldr_read_memory); + ldr_xdetach (fake_ldr_process); + if (ldr_xattach (fake_ldr_process) != 0 + || ldr_next_module(fake_ldr_process, &mod_id) != 0 || mod_id == LDR_NULL_MODULE - || ldr_inq_module(inferior_pid, mod_id, + || ldr_inq_module(fake_ldr_process, mod_id, &first_lm.module_info, sizeof(ldr_module_info_t), &retsize) != 0) return lm; @@ -287,12 +356,12 @@ next_link_map_member (so_list_ptr) struct link_map *lm = NULL; static struct link_map next_lm; #ifdef USE_LDR_ROUTINES - ldr_module_t mod_id = lm->module_info.lmi_modid; + ldr_module_t mod_id = so_list_ptr->lm.module_info.lmi_modid; size_t retsize; - if (ldr_next_module(inferior_pid, &mod_id) != 0 + if (ldr_next_module(fake_ldr_process, &mod_id) != 0 || mod_id == LDR_NULL_MODULE - || ldr_inq_module(inferior_pid, mod_id, + || ldr_inq_module(fake_ldr_process, mod_id, &next_lm.module_info, sizeof(ldr_module_info_t), &retsize) != 0) return lm; @@ -327,10 +396,21 @@ xfer_link_map_member (so_list_ptr, lm) struct so_list *so_list_ptr; struct link_map *lm; { + int i; so_list_ptr->lm = *lm; - /* OSF/1 has absolute addresses in shared libraries. */ - LM_ADDR (so_list_ptr) = 0; + /* OSF/1 shared libraries are pre-linked to particular addresses, + but the runtime loader may have to relocate them if the + address ranges of the libraries used by the target executable clash, + or if the target executable is linked with the -taso option. + The offset is the difference between the address where the shared + library is mapped and the pre-linked address of the shared library. + + FIXME: GDB is currently unable to relocate the shared library + sections by different offsets. If sections are relocated by + different offsets, put out a warning and use the offset of the + first section for all remaining sections. */ + LM_OFFSET (so_list_ptr) = 0; /* There is one entry that has no name (for the inferior executable) since it is not a shared object. */ @@ -343,6 +423,26 @@ xfer_link_map_member (so_list_ptr, lm) if (len > MAX_PATH_SIZE) len = MAX_PATH_SIZE; strncpy (so_list_ptr->so_name, LM_NAME (so_list_ptr), MAX_PATH_SIZE); + so_list_ptr->so_name[MAX_PATH_SIZE - 1] = '\0'; + + for (i = 0; i < lm->module_info.lmi_nregion; i++) + { + ldr_region_info_t region_info; + size_t retsize; + CORE_ADDR region_offset; + + if (ldr_inq_region (fake_ldr_process, lm->module_info.lmi_modid, + i, ®ion_info, sizeof (region_info), + &retsize) != 0) + break; + region_offset = (CORE_ADDR) region_info.lri_mapaddr + - (CORE_ADDR) region_info.lri_vaddr; + if (i == 0) + LM_OFFSET (so_list_ptr) = region_offset; + else if (LM_OFFSET (so_list_ptr) != region_offset) + warning ("cannot handle shared library relocation for %s (%s)", + so_list_ptr->so_name, region_info.lri_name); + } #else int errcode; char *buffer; @@ -353,9 +453,37 @@ xfer_link_map_member (so_list_ptr, lm) safe_strerror (errcode)); strncpy (so_list_ptr->so_name, buffer, MAX_PATH_SIZE - 1); free (buffer); -#endif so_list_ptr->so_name[MAX_PATH_SIZE - 1] = '\0'; + for (i = 0; i < lm->module_info.region_count; i++) + { + ldr_region_info_t region_info; + CORE_ADDR region_offset; + + if (target_read_memory (lm->module_info.regioninfo_addr + + i * sizeof (region_info), + (char *) ®ion_info, + sizeof (region_info)) != 0) + break; + region_offset = region_info.mapaddr - region_info.vaddr; + if (i == 0) + LM_OFFSET (so_list_ptr) = region_offset; + else if (LM_OFFSET (so_list_ptr) != region_offset) + { + char *region_name; + target_read_string (region_info.regionname_addr, &buffer, + MAX_PATH_SIZE - 1, &errcode); + if (errcode == 0) + region_name = buffer; + else + region_name = "??"; + warning ("cannot handle shared library relocation for %s (%s)", + so_list_ptr->so_name, region_name); + free (buffer); + } + } +#endif + solib_map_sections (so_list_ptr); } }