diff options
Diffstat (limited to 'gdb/i386-linux-tdep.c')
| -rw-r--r-- | gdb/i386-linux-tdep.c | 100 |
1 files changed, 48 insertions, 52 deletions
diff --git a/gdb/i386-linux-tdep.c b/gdb/i386-linux-tdep.c index afff548..e666610 100644 --- a/gdb/i386-linux-tdep.c +++ b/gdb/i386-linux-tdep.c @@ -81,7 +81,7 @@ i386_linux_register_reggroup_p (struct gdbarch *gdbarch, int regnum, The instruction sequence for normal signals is pop %eax - mov $0x77,%eax + mov $0x77, %eax int $0x80 or 0x58 0xb8 0x77 0x00 0x00 0x00 0xcd 0x80. @@ -103,17 +103,17 @@ i386_linux_register_reggroup_p (struct gdbarch *gdbarch, int regnum, to the ones used by the kernel. Therefore, these trampolines are supported too. */ -#define LINUX_SIGTRAMP_INSN0 (0x58) /* pop %eax */ -#define LINUX_SIGTRAMP_OFFSET0 (0) -#define LINUX_SIGTRAMP_INSN1 (0xb8) /* mov $NNNN,%eax */ -#define LINUX_SIGTRAMP_OFFSET1 (1) -#define LINUX_SIGTRAMP_INSN2 (0xcd) /* int */ -#define LINUX_SIGTRAMP_OFFSET2 (6) +#define LINUX_SIGTRAMP_INSN0 0x58 /* pop %eax */ +#define LINUX_SIGTRAMP_OFFSET0 0 +#define LINUX_SIGTRAMP_INSN1 0xb8 /* mov $NNNN, %eax */ +#define LINUX_SIGTRAMP_OFFSET1 1 +#define LINUX_SIGTRAMP_INSN2 0xcd /* int */ +#define LINUX_SIGTRAMP_OFFSET2 6 static const unsigned char linux_sigtramp_code[] = { LINUX_SIGTRAMP_INSN0, /* pop %eax */ - LINUX_SIGTRAMP_INSN1, 0x77, 0x00, 0x00, 0x00, /* mov $0x77,%eax */ + LINUX_SIGTRAMP_INSN1, 0x77, 0x00, 0x00, 0x00, /* mov $0x77, %eax */ LINUX_SIGTRAMP_INSN2, 0x80 /* int $0x80 */ }; @@ -167,20 +167,20 @@ i386_linux_sigtramp_start (CORE_ADDR pc) /* This function does the same for RT signals. Here the instruction sequence is - mov $0xad,%eax + mov $0xad, %eax int $0x80 or 0xb8 0xad 0x00 0x00 0x00 0xcd 0x80. The effect is to call the system call rt_sigreturn. */ -#define LINUX_RT_SIGTRAMP_INSN0 (0xb8) /* mov $NNNN,%eax */ -#define LINUX_RT_SIGTRAMP_OFFSET0 (0) -#define LINUX_RT_SIGTRAMP_INSN1 (0xcd) /* int */ -#define LINUX_RT_SIGTRAMP_OFFSET1 (5) +#define LINUX_RT_SIGTRAMP_INSN0 0xb8 /* mov $NNNN, %eax */ +#define LINUX_RT_SIGTRAMP_OFFSET0 0 +#define LINUX_RT_SIGTRAMP_INSN1 0xcd /* int */ +#define LINUX_RT_SIGTRAMP_OFFSET1 5 static const unsigned char linux_rt_sigtramp_code[] = { - LINUX_RT_SIGTRAMP_INSN0, 0xad, 0x00, 0x00, 0x00, /* mov $0xad,%eax */ + LINUX_RT_SIGTRAMP_INSN0, 0xad, 0x00, 0x00, 0x00, /* mov $0xad, %eax */ LINUX_RT_SIGTRAMP_INSN1, 0x80 /* int $0x80 */ }; @@ -239,50 +239,47 @@ i386_linux_pc_in_sigtramp (CORE_ADDR pc, char *name) || strcmp ("__restore_rt", name) == 0); } -/* Assuming FRAME is for a GNU/Linux sigtramp routine, return the - address of the associated sigcontext structure. */ +/* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */ +#define I386_LINUX_UCONTEXT_SIGCONTEXT_OFFSET 20 + +/* Assuming NEXT_FRAME is a frame following a GNU/Linux sigtramp + routine, return the address of the associated sigcontext structure. */ static CORE_ADDR -i386_linux_sigcontext_addr (struct frame_info *frame) +i386_linux_sigcontext_addr (struct frame_info *next_frame) { CORE_ADDR pc; + CORE_ADDR sp; + char buf[4]; + + frame_unwind_register (next_frame, SP_REGNUM, buf); + sp = extract_unsigned_integer (buf, 4); - pc = i386_linux_sigtramp_start (get_frame_pc (frame)); + pc = i386_linux_sigtramp_start (frame_pc_unwind (next_frame)); if (pc) { - CORE_ADDR sp; - - if (get_next_frame (frame)) - /* If this isn't the top frame, the next frame must be for the - signal handler itself. The sigcontext structure lives on - the stack, right after the signum argument. */ - return get_frame_base (get_next_frame (frame)) + 12; - - /* This is the top frame. We'll have to find the address of the - sigcontext structure by looking at the stack pointer. Keep - in mind that the first instruction of the sigtramp code is - "pop %eax". If the PC is at this instruction, adjust the - returned value accordingly. */ - sp = read_register (SP_REGNUM); - if (pc == get_frame_pc (frame)) + /* The sigcontext structure lives on the stack, right after + the signum argument. We determine the address of the + sigcontext structure by looking at the frame's stack + pointer. Keep in mind that the first instruction of the + sigtramp code is "pop %eax". If the PC is after this + instruction, adjust the returned value accordingly. */ + if (pc == frame_pc_unwind (next_frame)) return sp + 4; return sp; } - pc = i386_linux_rt_sigtramp_start (get_frame_pc (frame)); + pc = i386_linux_rt_sigtramp_start (frame_pc_unwind (next_frame)); if (pc) { - if (get_next_frame (frame)) - /* If this isn't the top frame, the next frame must be for the - signal handler itself. The sigcontext structure is part of - the user context. A pointer to the user context is passed - as the third argument to the signal handler. */ - return read_memory_integer (get_frame_base (get_next_frame (frame)) - + 16, 4) + 20; - - /* This is the top frame. Again, use the stack pointer to find - the address of the sigcontext structure. */ - return read_memory_integer (read_register (SP_REGNUM) + 8, 4) + 20; + CORE_ADDR ucontext_addr; + + /* The sigcontext structure is part of the user context. A + pointer to the user context is passed as the third argument + to the signal handler. */ + read_memory (sp + 8, buf, 4); + ucontext_addr = extract_unsigned_integer (buf, 4) + 20; + return ucontext_addr + I386_LINUX_UCONTEXT_SIGCONTEXT_OFFSET; } error ("Couldn't recognize signal trampoline."); @@ -322,7 +319,7 @@ i386_linux_write_pc (CORE_ADDR pc, ptid_t ptid) be considered too special-purpose for general consumption. */ static struct minimal_symbol * -find_minsym_and_objfile (char *name, struct objfile **objfile_p) +find_minsym_and_objfile (char *name, struct objfile **objfilep) { struct objfile *objfile; @@ -335,7 +332,7 @@ find_minsym_and_objfile (char *name, struct objfile **objfile_p) if (SYMBOL_LINKAGE_NAME (msym) && strcmp (SYMBOL_LINKAGE_NAME (msym), name) == 0) { - *objfile_p = objfile; + *objfilep = objfile; return msym; } } @@ -345,9 +342,9 @@ find_minsym_and_objfile (char *name, struct objfile **objfile_p) } static CORE_ADDR -skip_hurd_resolver (CORE_ADDR pc) +skip_gnu_resolver (CORE_ADDR pc) { - /* The HURD dynamic linker is part of the GNU C library, so many + /* The GNU dynamic linker is part of the GNU C library, so many GNU/Linux distributions use it. (All ELF versions, as far as I know.) An unresolved PLT entry points to "_dl_runtime_resolve", which calls "fixup" to patch the PLT, and then passes control to @@ -374,7 +371,7 @@ skip_hurd_resolver (CORE_ADDR pc) = lookup_minimal_symbol ("fixup", NULL, objfile); if (fixup && SYMBOL_VALUE_ADDRESS (fixup) == pc) - return (DEPRECATED_SAVED_PC_AFTER_CALL (get_current_frame ())); + return frame_pc_unwind (get_current_frame ()); } return 0; @@ -393,7 +390,7 @@ i386_linux_skip_solib_resolver (CORE_ADDR pc) CORE_ADDR result; /* Plug in functions for other kinds of resolvers here. */ - result = skip_hurd_resolver (pc); + result = skip_gnu_resolver (pc); if (result) return result; @@ -461,7 +458,6 @@ i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) set_gdbarch_num_regs (gdbarch, I386_SSE_NUM_REGS + 1); set_gdbarch_register_name (gdbarch, i386_linux_register_name); set_gdbarch_register_reggroup_p (gdbarch, i386_linux_register_reggroup_p); - set_gdbarch_deprecated_register_bytes (gdbarch, I386_SSE_SIZEOF_REGS + 4); tdep->jb_pc_offset = 20; /* From <bits/setjmp.h>. */ |