+2008-10-02 Daniel Jacobowitz <dan@codesourcery.com>
+
+ * mips-linux-tdep.c (mips_linux_in_dynsym_resolve_code): Update
+ comments.
+ (mips_linux_skip_resolver): Also use glibc_skip_solib_resolver.
+ (mips_linux_init_abi): Do not override skip_trampoline_code.
+ * configure.tgt (mips*-*-linux*): Add glibc-tdep.o.
+ * mips-tdep.c (mips32_scan_prologue): Stop scanning at branches.
+ (mips_stub_frame_sniffer): Use the stub frame sniffer for PIC stubs.
+ (mips_skip_mips16_trampoline_code): Rename from
+ mips_skip_trampoline_code.
+ (mips_skip_pic_trampoline_code, mips_skip_trampoline_code): New.
+ * infrun.c (handle_inferior_event): Do not pass zero to
+ in_solib_dynsym_resolve_code.
+
2008-10-02 Pierre Muller <muller@ics.u-strasbg.fr>
Pedro Alves <pedro@codesourcery.com>
#include "symtab.h"
#include "target-descriptions.h"
#include "mips-linux-tdep.h"
+#include "glibc-tdep.h"
static struct target_so_ops mips_svr4_so_ops;
}
/* Return non-zero iff PC belongs to the dynamic linker resolution
- code or to a stub. */
+ code, a PLT entry, or a lazy binding stub. */
static int
mips_linux_in_dynsym_resolve_code (CORE_ADDR pc)
{
/* Check whether PC is in the dynamic linker. This also checks
- whether it is in the .plt section, which MIPS does not use. */
+ whether it is in the .plt section, used by non-PIC executables. */
if (svr4_in_dynsym_resolve_code (pc))
return 1;
and glibc_skip_solib_resolver in glibc-tdep.c. The normal glibc
implementation of this triggers at "fixup" from the same objfile as
"_dl_runtime_resolve"; MIPS GNU/Linux can trigger at
- "__dl_runtime_resolve" directly. An unresolved PLT entry will
- point to _dl_runtime_resolve, which will first call
+ "__dl_runtime_resolve" directly. An unresolved lazy binding
+ stub will point to _dl_runtime_resolve, which will first call
__dl_runtime_resolve, and then pass control to the resolved
function. */
if (resolver && SYMBOL_VALUE_ADDRESS (resolver) == pc)
return frame_pc_unwind (get_current_frame ());
- return 0;
+ return glibc_skip_solib_resolver (gdbarch, pc);
}
/* Signal trampoline support. There are four supported layouts for a
break;
}
- set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
set_gdbarch_skip_solib_resolver (gdbarch, mips_linux_skip_resolver);
set_gdbarch_software_single_step (gdbarch, mips_software_single_step);
CORE_ADDR end_prologue_addr = 0;
int seen_sp_adjust = 0;
int load_immediate_bytes = 0;
+ int in_delay_slot = 0;
struct gdbarch *gdbarch = get_frame_arch (this_frame);
int regsize_is_64_bits = (mips_abi_regsize (gdbarch) == 8);
instructions? */
if (end_prologue_addr == 0)
end_prologue_addr = cur_pc;
+
+ /* Check for branches and jumps. For now, only jump to
+ register are caught (i.e. returns). */
+ if ((itype_op (inst) & 0x07) == 0 && rtype_funct (inst) == 8)
+ in_delay_slot = 1;
}
+
+ /* If the previous instruction was a jump, we must have reached
+ the end of the prologue by now. Stop scanning so that we do
+ not go past the function return. */
+ if (in_delay_slot)
+ break;
}
if (this_cache != NULL)
gdb_byte dummy[4];
struct obj_section *s;
CORE_ADDR pc = get_frame_address_in_block (this_frame);
+ struct minimal_symbol *msym;
/* Use the stub unwinder for unreadable code. */
if (target_read_memory (get_frame_pc (this_frame), dummy, 4) != 0)
".MIPS.stubs") == 0)
return 1;
+ /* Calling a PIC function from a non-PIC function passes through a
+ stub. The stub for foo is named ".pic.foo". */
+ msym = lookup_minimal_symbol_by_pc (pc);
+ if (msym != NULL
+ && SYMBOL_LINKAGE_NAME (msym) != NULL
+ && strncmp (SYMBOL_LINKAGE_NAME (msym), ".pic.", 5) == 0)
+ return 1;
+
return 0;
}
gory details. */
static CORE_ADDR
-mips_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
+mips_skip_mips16_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
{
char *name;
CORE_ADDR start_addr;
return 0; /* not a stub */
}
+/* If the current PC is the start of a non-PIC-to-PIC stub, return the
+ PC of the stub target. The stub just loads $t9 and jumps to it,
+ so that $t9 has the correct value at function entry. */
+
+static CORE_ADDR
+mips_skip_pic_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
+{
+ struct minimal_symbol *msym;
+ int i;
+ gdb_byte stub_code[16];
+ int32_t stub_words[4];
+
+ /* The stub for foo is named ".pic.foo", and is either two
+ instructions inserted before foo or a three instruction sequence
+ which jumps to foo. */
+ msym = lookup_minimal_symbol_by_pc (pc);
+ if (msym == NULL
+ || SYMBOL_VALUE_ADDRESS (msym) != pc
+ || SYMBOL_LINKAGE_NAME (msym) == NULL
+ || strncmp (SYMBOL_LINKAGE_NAME (msym), ".pic.", 5) != 0)
+ return 0;
+
+ /* A two-instruction header. */
+ if (MSYMBOL_SIZE (msym) == 8)
+ return pc + 8;
+
+ /* A three-instruction (plus delay slot) trampoline. */
+ if (MSYMBOL_SIZE (msym) == 16)
+ {
+ if (target_read_memory (pc, stub_code, 16) != 0)
+ return 0;
+ for (i = 0; i < 4; i++)
+ stub_words[i] = extract_unsigned_integer (stub_code + i * 4, 4);
+
+ /* A stub contains these instructions:
+ lui t9, %hi(target)
+ j target
+ addiu t9, t9, %lo(target)
+ nop
+
+ This works even for N64, since stubs are only generated with
+ -msym32. */
+ if ((stub_words[0] & 0xffff0000U) == 0x3c190000
+ && (stub_words[1] & 0xfc000000U) == 0x08000000
+ && (stub_words[2] & 0xffff0000U) == 0x27390000
+ && stub_words[3] == 0x00000000)
+ return (((stub_words[0] & 0x0000ffff) << 16)
+ + (stub_words[2] & 0x0000ffff));
+ }
+
+ /* Not a recognized stub. */
+ return 0;
+}
+
+static CORE_ADDR
+mips_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
+{
+ CORE_ADDR target_pc;
+
+ target_pc = mips_skip_mips16_trampoline_code (frame, pc);
+ if (target_pc)
+ return target_pc;
+
+ target_pc = find_solib_trampoline_target (frame, pc);
+ if (target_pc)
+ return target_pc;
+
+ target_pc = mips_skip_pic_trampoline_code (frame, pc);
+ if (target_pc)
+ return target_pc;
+
+ return 0;
+}
+
/* Convert a dbx stab register number (from `r' declaration) to a GDB
[1 * gdbarch_num_regs .. 2 * gdbarch_num_regs) REGNUM. */
projects / binutils-gdb.git / commitdiff