/* Target-dependent code for GNU/Linux running on x86-64, for GDB.
- Copyright 2001 Free Software Foundation, Inc.
+ Copyright 2001, 2003 Free Software Foundation, Inc.
Contributed by Jiri Smid, SuSE Labs.
#include "defs.h"
#include "inferior.h"
#include "gdbcore.h"
-#include "gdb_string.h"
#include "regcache.h"
+#include "osabi.h"
+
+#include "gdb_string.h"
+
#include "x86-64-tdep.h"
-#include "dwarf2cfi.h"
-#define LINUX_SIGTRAMP_INSN0 (0x48) /* mov $NNNNNNNN,%rax */
-#define LINUX_SIGTRAMP_OFFSET0 (0)
-#define LINUX_SIGTRAMP_INSN1 (0x0f) /* syscall */
-#define LINUX_SIGTRAMP_OFFSET1 (7)
+#define LINUX_SIGTRAMP_INSN0 0x48 /* mov $NNNNNNNN, %rax */
+#define LINUX_SIGTRAMP_OFFSET0 0
+#define LINUX_SIGTRAMP_INSN1 0x0f /* syscall */
+#define LINUX_SIGTRAMP_OFFSET1 7
-static const unsigned char linux_sigtramp_code[] = {
- /* mov $__NR_rt_sigreturn,%rax */
+static const unsigned char linux_sigtramp_code[] =
+{
+ /* mov $__NR_rt_sigreturn, %rax */
LINUX_SIGTRAMP_INSN0, 0xc7, 0xc0, 0x0f, 0x00, 0x00, 0x00,
/* syscall */
LINUX_SIGTRAMP_INSN1, 0x05
x86_64_linux_sigtramp_start (CORE_ADDR pc)
{
unsigned char buf[LINUX_SIGTRAMP_LEN];
+
+ /* We only recognize a signal trampoline if PC is at the start of
+ one of the two instructions. We optimize for finding the PC at
+ the start, as will be the case when the trampoline is not the
+ first frame on the stack. We assume that in the case where the
+ PC is not at the start of the instruction sequence, there will be
+ a few trailing readable bytes on the stack. */
+
if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
return 0;
return pc;
}
-#define LINUX_SIGINFO_SIZE 0
-
-/* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */
-#define LINUX_UCONTEXT_SIGCONTEXT_OFFSET 40
-
-/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>. */
-#define LINUX_SIGCONTEXT_PC_OFFSET 128
-#define LINUX_SIGCONTEXT_FP_OFFSET 120
+/* Return whether PC is in a GNU/Linux sigtramp routine. */
-/* Assuming FRAME is for a GNU/Linux sigtramp routine, return the
- address of the associated sigcontext structure. */
-static CORE_ADDR
-x86_64_linux_sigcontext_addr (struct frame_info *frame)
+static int
+x86_64_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
{
- CORE_ADDR pc;
- ULONGEST rsp;
-
- pc = x86_64_linux_sigtramp_start (frame->pc);
- if (pc)
- {
- if (frame->next)
- /* 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. */
- return frame->next->frame + LINUX_SIGINFO_SIZE +
- LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
-
-
- /* This is the top frame. */
- rsp = read_register (SP_REGNUM);
- return rsp + LINUX_SIGINFO_SIZE + LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
-
- }
-
- error ("Couldn't recognize signal trampoline.");
- return 0;
+ /* If we have NAME, we can optimize the search. The trampoline is
+ named __restore_rt. However, it isn't dynamically exported from
+ the shared C library, so the trampoline may appear to be part of
+ the preceding function. This should always be sigaction,
+ __sigaction, or __libc_sigaction (all aliases to the same
+ function). */
+ if (name == NULL || strstr (name, "sigaction") != NULL)
+ return (x86_64_linux_sigtramp_start (pc) != 0);
+
+ return (strcmp ("__restore_rt", name) == 0);
}
-/* Assuming FRAME is for a GNU/Linux sigtramp routine, return the
- saved program counter. */
-
-static CORE_ADDR
-x86_64_linux_sigtramp_saved_pc (struct frame_info *frame)
-{
- CORE_ADDR addr;
-
- addr = x86_64_linux_sigcontext_addr (frame);
- return read_memory_integer (addr + LINUX_SIGCONTEXT_PC_OFFSET, 8);
-}
-
-/* Immediately after a function call, return the saved pc. */
-
-CORE_ADDR
-x86_64_linux_saved_pc_after_call (struct frame_info *frame)
-{
- if (frame->signal_handler_caller)
- return x86_64_linux_sigtramp_saved_pc (frame);
+/* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */
+#define X86_64_LINUX_UCONTEXT_SIGCONTEXT_OFFSET 40
- return read_memory_integer (read_register (SP_REGNUM), 8);
-}
+/* Assuming NEXT_FRAME is a frame following a GNU/Linux sigtramp
+ routine, return the address of the associated sigcontext structure. */
-/* Saved Pc. Get it from sigcontext if within sigtramp. */
-CORE_ADDR
-x86_64_linux_frame_saved_pc (struct frame_info *frame)
+static CORE_ADDR
+x86_64_linux_sigcontext_addr (struct frame_info *next_frame)
{
- if (frame->signal_handler_caller)
- return x86_64_linux_sigtramp_saved_pc (frame);
- return cfi_get_ra (frame);
+ CORE_ADDR sp;
+ char buf[8];
+
+ frame_unwind_register (next_frame, SP_REGNUM, buf);
+ sp = extract_unsigned_integer (buf, 8);
+
+ /* 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, i.e. in %rdx. Unfortunately %rdx isn't preserved across
+ function calls so we can't use it. Fortunately the user context
+ is part of the signal frame and the unwound %rsp directly points
+ at it. */
+ return sp + X86_64_LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
}
+\f
-/* Return whether PC is in a GNU/Linux sigtramp routine. */
-
-int
-x86_64_linux_in_sigtramp (CORE_ADDR pc, char *name)
+/* From <asm/sigcontext.h>. */
+static int x86_64_linux_sc_reg_offset[X86_64_NUM_GREGS] =
{
- if (name)
- return STREQ ("__restore_rt", name);
-
- return (x86_64_linux_sigtramp_start (pc) != 0);
-}
+ 13 * 8, /* %rax */
+ 11 * 8, /* %rbx */
+ 14 * 8, /* %rcx */
+ 12 * 8, /* %rdx */
+ 9 * 8, /* %rsi */
+ 8 * 8, /* %rdi */
+ 10 * 8, /* %rbp */
+ 15 * 8, /* %rsp */
+ 0 * 8, /* %r8 */
+ 1 * 8, /* %r9 */
+ 2 * 8, /* %r10 */
+ 3 * 8, /* %r11 */
+ 4 * 8, /* %r12 */
+ 5 * 8, /* %r13 */
+ 6 * 8, /* %r14 */
+ 7 * 8, /* %r15 */
+ 16 * 8, /* %rip */
+ 17 * 8, /* %eflags */
+ -1, /* %ds */
+ -1, /* %es */
+
+ /* FIXME: kettenis/2002030531: The registers %fs and %gs are
+ available in `struct sigcontext'. However, they only occupy two
+ bytes instead of four, which makes using them here rather
+ difficult. Leave them out for now. */
+ -1, /* %fs */
+ -1 /* %gs */
+};
-CORE_ADDR
-x86_64_linux_frame_chain (struct frame_info *fi)
+static void
+x86_64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
- ULONGEST addr;
- CORE_ADDR fp, pc;
-
- if (!fi->signal_handler_caller)
- {
- fp = cfi_frame_chain (fi);
- if (fp)
- return fp;
- else
- addr = fi->frame;
- }
- else
- addr = fi->next->frame;
-
- addr += LINUX_SIGINFO_SIZE + LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ x86_64_init_abi (info, gdbarch);
- fp = read_memory_integer (addr + LINUX_SIGCONTEXT_FP_OFFSET, 8) + 8;
+ set_gdbarch_pc_in_sigtramp (gdbarch, x86_64_linux_pc_in_sigtramp);
- return fp;
+ tdep->sigcontext_addr = x86_64_linux_sigcontext_addr;
+ tdep->sc_reg_offset = x86_64_linux_sc_reg_offset;
+ tdep->sc_num_regs = X86_64_NUM_GREGS;
}
+\f
-void
-x86_64_init_frame_pc (int fromleaf, struct frame_info *fi)
-{
- CORE_ADDR addr;
-
- if (fi->next && fi->next->signal_handler_caller)
- {
- addr = fi->next->next->frame
- + LINUX_SIGINFO_SIZE + LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
- fi->pc = read_memory_integer (addr + LINUX_SIGCONTEXT_PC_OFFSET, 8);
- }
- else
- cfi_init_frame_pc (fromleaf, fi);
-}
+/* Provide a prototype to silence -Wmissing-prototypes. */
+extern void _initialize_x86_64_linux_tdep (void);
void
-x86_64_init_extra_frame_info (int fromleaf, struct frame_info *fi)
+_initialize_x86_64_linux_tdep (void)
{
- cfi_init_extra_frame_info (fromleaf, fi);
+ gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64, GDB_OSABI_LINUX,
+ x86_64_linux_init_abi);
}
projects / deliverable / binutils-gdb.git / blobdiff