Add a helper function to resolve TLS variable addresses for FreeBSD.
The fbsd_get_thread_local_address function accepts the base address of a thread's DTV array and the base address of an object file's link map and uses this to compute a TLS variable's address. FreeBSD architectures use an architecture-specific method to determine the address of the DTV array pointer and call this helper function to perform the rest of the address calculation. * fbsd-tdep.c (fbsd_pspace_data_handle): New variable. (struct fbsd_pspace_data): New type. (get_fbsd_pspace_data, fbsd_pspace_data_cleanup) (fbsd_read_integer_by_name, fbsd_fetch_rtld_offsets) (fbsd_get_tls_index, fbsd_get_thread_local_address): New function. (_initialize_fbsd_tdep): Initialize 'fbsd_pspace_data_handle'. * fbsd-tdep.c (fbsd_get_thread_local_address): New prototype.
This commit is contained in:
John Baldwin
parent
ef0bd2046f
commit
945f3901b5
|
|
@ -1,3 +1,13 @@
|
|||
2019-03-12 John Baldwin <jhb@FreeBSD.org>
|
||||
|
||||
* fbsd-tdep.c (fbsd_pspace_data_handle): New variable.
|
||||
(struct fbsd_pspace_data): New type.
|
||||
(get_fbsd_pspace_data, fbsd_pspace_data_cleanup)
|
||||
(fbsd_read_integer_by_name, fbsd_fetch_rtld_offsets)
|
||||
(fbsd_get_tls_index, fbsd_get_thread_local_address): New function.
|
||||
(_initialize_fbsd_tdep): Initialize 'fbsd_pspace_data_handle'.
|
||||
* fbsd-tdep.c (fbsd_get_thread_local_address): New prototype.
|
||||
|
||||
2019-03-12 John Baldwin <jhb@FreeBSD.org>
|
||||
|
||||
* gdbtypes.c (lookup_struct_elt): New function.
|
||||
|
|
|
|||
153
gdb/fbsd-tdep.c
153
gdb/fbsd-tdep.c
|
|
@ -24,6 +24,7 @@
|
|||
#include "regcache.h"
|
||||
#include "regset.h"
|
||||
#include "gdbthread.h"
|
||||
#include "objfiles.h"
|
||||
#include "xml-syscall.h"
|
||||
#include <sys/socket.h>
|
||||
#include <arpa/inet.h>
|
||||
|
|
@ -444,6 +445,41 @@ get_fbsd_gdbarch_data (struct gdbarch *gdbarch)
|
|||
gdbarch_data (gdbarch, fbsd_gdbarch_data_handle));
|
||||
}
|
||||
|
||||
/* Per-program-space data for FreeBSD architectures. */
|
||||
static const struct program_space_data *fbsd_pspace_data_handle;
|
||||
|
||||
struct fbsd_pspace_data
|
||||
{
|
||||
/* Offsets in the runtime linker's 'Obj_Entry' structure. */
|
||||
LONGEST off_linkmap;
|
||||
LONGEST off_tlsindex;
|
||||
bool rtld_offsets_valid;
|
||||
};
|
||||
|
||||
static struct fbsd_pspace_data *
|
||||
get_fbsd_pspace_data (struct program_space *pspace)
|
||||
{
|
||||
struct fbsd_pspace_data *data;
|
||||
|
||||
data = ((struct fbsd_pspace_data *)
|
||||
program_space_data (pspace, fbsd_pspace_data_handle));
|
||||
if (data == NULL)
|
||||
{
|
||||
data = XCNEW (struct fbsd_pspace_data);
|
||||
set_program_space_data (pspace, fbsd_pspace_data_handle, data);
|
||||
}
|
||||
|
||||
return data;
|
||||
}
|
||||
|
||||
/* The cleanup callback for FreeBSD architecture per-program-space data. */
|
||||
|
||||
static void
|
||||
fbsd_pspace_data_cleanup (struct program_space *pspace, void *data)
|
||||
{
|
||||
xfree (data);
|
||||
}
|
||||
|
||||
/* This is how we want PTIDs from core files to be printed. */
|
||||
|
||||
static const char *
|
||||
|
|
@ -1932,6 +1968,121 @@ fbsd_get_syscall_number (struct gdbarch *gdbarch, thread_info *thread)
|
|||
internal_error (__FILE__, __LINE__, _("fbsd_get_sycall_number called"));
|
||||
}
|
||||
|
||||
/* Read an integer symbol value from the current target. */
|
||||
|
||||
static LONGEST
|
||||
fbsd_read_integer_by_name (struct gdbarch *gdbarch, const char *name)
|
||||
{
|
||||
bound_minimal_symbol ms = lookup_minimal_symbol (name, NULL, NULL);
|
||||
if (ms.minsym == NULL)
|
||||
error (_("Unable to resolve symbol '%s'"), name);
|
||||
|
||||
gdb_byte buf[4];
|
||||
if (target_read_memory (BMSYMBOL_VALUE_ADDRESS (ms), buf, sizeof buf) != 0)
|
||||
error (_("Unable to read value of '%s'"), name);
|
||||
|
||||
return extract_signed_integer (buf, sizeof buf, gdbarch_byte_order (gdbarch));
|
||||
}
|
||||
|
||||
/* Lookup offsets of fields in the runtime linker's 'Obj_Entry'
|
||||
structure needed to determine the TLS index of an object file. */
|
||||
|
||||
static void
|
||||
fbsd_fetch_rtld_offsets (struct gdbarch *gdbarch, struct fbsd_pspace_data *data)
|
||||
{
|
||||
TRY
|
||||
{
|
||||
/* Fetch offsets from debug symbols in rtld. */
|
||||
struct symbol *obj_entry_sym
|
||||
= lookup_symbol_in_language ("Struct_Obj_Entry", NULL, STRUCT_DOMAIN,
|
||||
language_c, NULL).symbol;
|
||||
if (obj_entry_sym == NULL)
|
||||
error (_("Unable to find Struct_Obj_Entry symbol"));
|
||||
data->off_linkmap = lookup_struct_elt (SYMBOL_TYPE(obj_entry_sym),
|
||||
"linkmap", 0).offset / 8;
|
||||
data->off_tlsindex = lookup_struct_elt (SYMBOL_TYPE(obj_entry_sym),
|
||||
"tlsindex", 0).offset / 8;
|
||||
data->rtld_offsets_valid = true;
|
||||
return;
|
||||
}
|
||||
CATCH (e, RETURN_MASK_ERROR)
|
||||
{
|
||||
data->off_linkmap = -1;
|
||||
}
|
||||
END_CATCH
|
||||
|
||||
TRY
|
||||
{
|
||||
/* Fetch offsets from global variables in libthr. Note that
|
||||
this does not work for single-threaded processes that are not
|
||||
linked against libthr. */
|
||||
data->off_linkmap = fbsd_read_integer_by_name (gdbarch,
|
||||
"_thread_off_linkmap");
|
||||
data->off_tlsindex = fbsd_read_integer_by_name (gdbarch,
|
||||
"_thread_off_tlsindex");
|
||||
data->rtld_offsets_valid = true;
|
||||
return;
|
||||
}
|
||||
CATCH (e, RETURN_MASK_ERROR)
|
||||
{
|
||||
data->off_linkmap = -1;
|
||||
}
|
||||
END_CATCH
|
||||
}
|
||||
|
||||
/* Helper function to read the TLS index of an object file associated
|
||||
with a link map entry at LM_ADDR. */
|
||||
|
||||
static LONGEST
|
||||
fbsd_get_tls_index (struct gdbarch *gdbarch, CORE_ADDR lm_addr)
|
||||
{
|
||||
struct fbsd_pspace_data *data = get_fbsd_pspace_data (current_program_space);
|
||||
|
||||
if (!data->rtld_offsets_valid)
|
||||
fbsd_fetch_rtld_offsets (gdbarch, data);
|
||||
|
||||
if (data->off_linkmap == -1)
|
||||
throw_error (TLS_GENERIC_ERROR,
|
||||
_("Cannot fetch runtime linker structure offsets"));
|
||||
|
||||
/* Simulate container_of to convert from LM_ADDR to the Obj_Entry
|
||||
pointer and then compute the offset of the tlsindex member. */
|
||||
CORE_ADDR tlsindex_addr = lm_addr - data->off_linkmap + data->off_tlsindex;
|
||||
|
||||
gdb_byte buf[4];
|
||||
if (target_read_memory (tlsindex_addr, buf, sizeof buf) != 0)
|
||||
throw_error (TLS_GENERIC_ERROR,
|
||||
_("Cannot find thread-local variables on this target"));
|
||||
|
||||
return extract_signed_integer (buf, sizeof buf, gdbarch_byte_order (gdbarch));
|
||||
}
|
||||
|
||||
/* See fbsd-tdep.h. */
|
||||
|
||||
CORE_ADDR
|
||||
fbsd_get_thread_local_address (struct gdbarch *gdbarch, CORE_ADDR dtv_addr,
|
||||
CORE_ADDR lm_addr, CORE_ADDR offset)
|
||||
{
|
||||
LONGEST tls_index = fbsd_get_tls_index (gdbarch, lm_addr);
|
||||
|
||||
gdb_byte buf[gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT];
|
||||
if (target_read_memory (dtv_addr, buf, sizeof buf) != 0)
|
||||
throw_error (TLS_GENERIC_ERROR,
|
||||
_("Cannot find thread-local variables on this target"));
|
||||
|
||||
const struct builtin_type *builtin = builtin_type (gdbarch);
|
||||
CORE_ADDR addr = gdbarch_pointer_to_address (gdbarch,
|
||||
builtin->builtin_data_ptr, buf);
|
||||
|
||||
addr += (tls_index + 1) * TYPE_LENGTH (builtin->builtin_data_ptr);
|
||||
if (target_read_memory (addr, buf, sizeof buf) != 0)
|
||||
throw_error (TLS_GENERIC_ERROR,
|
||||
_("Cannot find thread-local variables on this target"));
|
||||
|
||||
addr = gdbarch_pointer_to_address (gdbarch, builtin->builtin_data_ptr, buf);
|
||||
return addr + offset;
|
||||
}
|
||||
|
||||
/* To be called from GDB_OSABI_FREEBSD handlers. */
|
||||
|
||||
void
|
||||
|
|
@ -1957,4 +2108,6 @@ _initialize_fbsd_tdep (void)
|
|||
{
|
||||
fbsd_gdbarch_data_handle =
|
||||
gdbarch_data_register_post_init (init_fbsd_gdbarch_data);
|
||||
fbsd_pspace_data_handle
|
||||
= register_program_space_data_with_cleanup (NULL, fbsd_pspace_data_cleanup);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -60,4 +60,15 @@ extern void fbsd_info_proc_mappings_entry (int addr_bit, ULONGEST kve_start,
|
|||
int kve_flags, int kve_protection,
|
||||
const void *kve_path);
|
||||
|
||||
/* Helper function to fetch the address of a thread-local variable.
|
||||
DTV_ADDR is the base address of the thread's dtv array. LM_ADDR is
|
||||
the address of the link_map structure for the associated object
|
||||
file. OFFSET is the offset of the variable in the object file's
|
||||
thread-local variable block. */
|
||||
|
||||
extern CORE_ADDR fbsd_get_thread_local_address (struct gdbarch *gdbarch,
|
||||
CORE_ADDR dtv_addr,
|
||||
CORE_ADDR lm_addr,
|
||||
CORE_ADDR offset);
|
||||
|
||||
#endif /* fbsd-tdep.h */
|
||||
|
|
|
|||
Loading…
Reference in New Issue