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-rw-r--r--gdb/ChangeLog42
-rw-r--r--gdb/Makefile.in6
-rw-r--r--gdb/config/i386/linux.mt2
-rw-r--r--gdb/i386-linux-nat.c258
-rw-r--r--gdb/i386-linux-tdep.c281
5 files changed, 309 insertions, 280 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index bd1b142..b715b30 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,25 @@
+2000-03-20 Jim Blandy <jimb@redhat.com>
+
+ * i386-linux-nat.c: No need to #include "frame.h" any more.
+ (LINUX_SIGTRAMP_INSN0, LINUX_SIGTRAMP_OFFSET0,
+ LINUX_SIGTRAMP_INSN1, LINUX_SIGTRAMP_OFFSET1,
+ LINUX_SIGTRAMP_INSN2, LINUX_SIGTRAMP_OFFSET2, linux_sigtramp_code,
+ LINUX_SIGTRAMP_LEN, i386_linux_sigtramp_start,
+ LINUX_RT_SIGTRAMP_INSN0, LINUX_RT_SIGTRAMP_OFFSET0,
+ LINUX_RT_SIGTRAMP_INSN1, LINUX_RT_SIGTRAMP_OFFSET1,
+ linux_rt_sigtramp_code, LINUX_RT_SIGTRAMP_LEN,
+ i386_linux_rt_sigtramp_start, i386_linux_in_sigtramp,
+ i386_linux_sigcontext_addr, LINUX_SIGCONTEXT_PC_OFFSET,
+ i386_linux_sigtramp_saved_pc, LINUX_SIGCONTEXT_SP_OFFSET,
+ i386_linux_sigtramp_saved_sp): Deleted. Folks rightly pointed
+ out that these are target-dependent, and useful in non-native
+ configurations. Moved to...
+ * i386-linux-tdep.c: ... Here, a new file.
+ * Makefile.in (ALLDEPFILES): Add i386-linux-tdep.c.
+ (i386-linux-tdep.o): New rule.
+ (i386-linux-nat.o): We no longer depend on frame.h.
+ * config/i386/linux.mt (TDEPFILES): Add i386-linux-tdep.o.
+
2000-03-04 Eli Zaretskii <eliz@is.elta.co.il>
* event-loop.c (top-level) [NO_FD_SET]: Deprecate this branch.
@@ -64,26 +86,6 @@ Mon Mar 20 17:33:32 2000 Andrew Cagney <cagney@b1.cygnus.com>
* gdb_wait.h (WSETSTOP): Pass the appropriate number of arguments
to W_STOPCODE.
- * i386-linux-nat.c: No need to #include "frame.h" any more.
- (LINUX_SIGTRAMP_INSN0, LINUX_SIGTRAMP_OFFSET0,
- LINUX_SIGTRAMP_INSN1, LINUX_SIGTRAMP_OFFSET1,
- LINUX_SIGTRAMP_INSN2, LINUX_SIGTRAMP_OFFSET2, linux_sigtramp_code,
- LINUX_SIGTRAMP_LEN, i386_linux_sigtramp_start,
- LINUX_RT_SIGTRAMP_INSN0, LINUX_RT_SIGTRAMP_OFFSET0,
- LINUX_RT_SIGTRAMP_INSN1, LINUX_RT_SIGTRAMP_OFFSET1,
- linux_rt_sigtramp_code, LINUX_RT_SIGTRAMP_LEN,
- i386_linux_rt_sigtramp_start, i386_linux_in_sigtramp,
- i386_linux_sigcontext_addr, LINUX_SIGCONTEXT_PC_OFFSET,
- i386_linux_sigtramp_saved_pc, LINUX_SIGCONTEXT_SP_OFFSET,
- i386_linux_sigtramp_saved_sp): Deleted. Folks rightly pointed
- out that these are target-dependent, and useful in non-native
- configurations. Moved to...
- * i386-linux-tdep.c: ... Here, a new file.
- * Makefile.in (ALLDEPFILES): Add i386-linux-tdep.c.
- (i386-linux-tdep.o): New rule.
- (i386-linux-nat.o): We no longer depend on frame.h.
- * config/i386/linux.mt (TDEPFILES): Add i386-linux-tdep.o.
-
* solib.c (solib_add): Delete debugging code.
2000-03-17 Mark Kettenis <kettenis@gnu.org>
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 72441ca..6046432 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -1063,6 +1063,7 @@ ALLDEPFILES = 29k-share/udi/udip2soc.c 29k-share/udi/udr.c \
i386-tdep.c i386b-nat.c i386mach-nat.c i386v-nat.c i386-linux-nat.c \
i386aix-nat.c i386m3-nat.c i386v4-nat.c i386ly-tdep.c \
i387-tdep.c \
+ i386-linux-tdep.c \
i960-tdep.c \
infptrace.c inftarg.c irix4-nat.c irix5-nat.c isi-xdep.c \
lynx-nat.c m3-nat.c \
@@ -1395,7 +1396,10 @@ i386v-nat.o: i386v-nat.c $(floatformat_h) $(defs_h) $(gdbcore_h) \
$(inferior_h) language.h target.h
i386-linux-nat.o: i386-linux-nat.c $(defs_h) $(inferior_h) $(gdbcore_h) \
- $(symtab_h) $(frame_h) symfile.h objfiles.h
+ $(symtab_h) symfile.h objfiles.h
+
+i386-linux-tdep.o: i386-linux-tdep.c $(defs_h) $(gdbcore_h) $(frame_h) \
+ $(value_h)
i386v4-nat.o: i386v4-nat.c $(defs_h)
diff --git a/gdb/config/i386/linux.mt b/gdb/config/i386/linux.mt
index 66cc97d..df17b18 100644
--- a/gdb/config/i386/linux.mt
+++ b/gdb/config/i386/linux.mt
@@ -1,5 +1,5 @@
# Target: Intel 386 running GNU/Linux
-TDEPFILES= i386-tdep.o i387-tdep.o
+TDEPFILES= i386-tdep.o i386-linux-tdep.o i387-tdep.o
TM_FILE= tm-linux.h
GDBSERVER_DEPFILES= low-linux.o
diff --git a/gdb/i386-linux-nat.c b/gdb/i386-linux-nat.c
index bf5e821..2e46ead 100644
--- a/gdb/i386-linux-nat.c
+++ b/gdb/i386-linux-nat.c
@@ -23,7 +23,6 @@
/* For i386_linux_skip_solib_resolver. */
#include "symtab.h"
-#include "frame.h"
#include "symfile.h"
#include "objfiles.h"
@@ -1044,263 +1043,6 @@ i386_linux_skip_solib_resolver (CORE_ADDR pc)
}
-/* Recognizing signal handler frames. */
-
-/* Linux has two flavors of signals. Normal signal handlers, and
- "realtime" (RT) signals. The RT signals can provide additional
- information to the signal handler if the SA_SIGINFO flag is set
- when establishing a signal handler using `sigaction'. It is not
- unlikely that future versions of Linux will support SA_SIGINFO for
- normal signals too. */
-
-/* When the i386 Linux kernel calls a signal handler and the
- SA_RESTORER flag isn't set, the return address points to a bit of
- code on the stack. This function returns whether the PC appears to
- be within this bit of code.
-
- The instruction sequence for normal signals is
- pop %eax
- mov $0x77,%eax
- int $0x80
- or 0x58 0xb8 0x77 0x00 0x00 0x00 0xcd 0x80.
-
- Checking for the code sequence should be somewhat reliable, because
- the effect is to call the system call sigreturn. This is unlikely
- to occur anywhere other than a signal trampoline.
-
- It kind of sucks that we have to read memory from the process in
- order to identify a signal trampoline, but there doesn't seem to be
- any other way. The IN_SIGTRAMP macro in tm-linux.h arranges to
- only call us if no function name could be identified, which should
- be the case since the code is on the stack.
-
- Detection of signal trampolines for handlers that set the
- SA_RESTORER flag is in general not possible. Unfortunately this is
- what the GNU C Library has been doing for quite some time now.
- However, as of version 2.1.2, the GNU C Library uses signal
- trampolines (named __restore and __restore_rt) that are identical
- 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)
-
-static const unsigned char linux_sigtramp_code[] =
-{
- LINUX_SIGTRAMP_INSN0, /* pop %eax */
- LINUX_SIGTRAMP_INSN1, 0x77, 0x00, 0x00, 0x00, /* mov $0x77,%eax */
- LINUX_SIGTRAMP_INSN2, 0x80 /* int $0x80 */
-};
-
-#define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
-
-/* If PC is in a sigtramp routine, return the address of the start of
- the routine. Otherwise, return 0. */
-
-static CORE_ADDR
-i386_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 three 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;
-
- if (buf[0] != LINUX_SIGTRAMP_INSN0)
- {
- int adjust;
-
- switch (buf[0])
- {
- case LINUX_SIGTRAMP_INSN1:
- adjust = LINUX_SIGTRAMP_OFFSET1;
- break;
- case LINUX_SIGTRAMP_INSN2:
- adjust = LINUX_SIGTRAMP_OFFSET2;
- break;
- default:
- return 0;
- }
-
- pc -= adjust;
-
- if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
- return 0;
- }
-
- if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
- return 0;
-
- return pc;
-}
-
-/* This function does the same for RT signals. Here the instruction
- sequence is
- 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)
-
-static const unsigned char linux_rt_sigtramp_code[] =
-{
- LINUX_RT_SIGTRAMP_INSN0, 0xad, 0x00, 0x00, 0x00, /* mov $0xad,%eax */
- LINUX_RT_SIGTRAMP_INSN1, 0x80 /* int $0x80 */
-};
-
-#define LINUX_RT_SIGTRAMP_LEN (sizeof linux_rt_sigtramp_code)
-
-/* If PC is in a RT sigtramp routine, return the address of the start
- of the routine. Otherwise, return 0. */
-
-static CORE_ADDR
-i386_linux_rt_sigtramp_start (CORE_ADDR pc)
-{
- unsigned char buf[LINUX_RT_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_RT_SIGTRAMP_LEN) != 0)
- return 0;
-
- if (buf[0] != LINUX_RT_SIGTRAMP_INSN0)
- {
- if (buf[0] != LINUX_RT_SIGTRAMP_INSN1)
- return 0;
-
- pc -= LINUX_RT_SIGTRAMP_OFFSET1;
-
- if (read_memory_nobpt (pc, (char *) buf, LINUX_RT_SIGTRAMP_LEN) != 0)
- return 0;
- }
-
- if (memcmp (buf, linux_rt_sigtramp_code, LINUX_RT_SIGTRAMP_LEN) != 0)
- return 0;
-
- return pc;
-}
-
-/* Return whether PC is in a Linux sigtramp routine. */
-
-int
-i386_linux_in_sigtramp (CORE_ADDR pc, char *name)
-{
- if (name)
- return STREQ ("__restore", name) || STREQ ("__restore_rt", name);
-
- return (i386_linux_sigtramp_start (pc) != 0
- || i386_linux_rt_sigtramp_start (pc) != 0);
-}
-
-/* Assuming FRAME is for a Linux sigtramp routine, return the address
- of the associated sigcontext structure. */
-
-CORE_ADDR
-i386_linux_sigcontext_addr (struct frame_info *frame)
-{
- CORE_ADDR pc;
-
- pc = i386_linux_sigtramp_start (frame->pc);
- if (pc)
- {
- CORE_ADDR sp;
-
- if (frame->next)
- /* 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 frame->next->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 == frame->pc)
- return sp + 4;
- return sp;
- }
-
- pc = i386_linux_rt_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. A pointer to the user context is passed
- as the third argument to the signal handler. */
- return read_memory_integer (frame->next->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;
- }
-
- error ("Couldn't recognize signal trampoline.");
- return 0;
-}
-
-/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>. */
-#define LINUX_SIGCONTEXT_PC_OFFSET (56)
-
-/* Assuming FRAME is for a Linux sigtramp routine, return the saved
- program counter. */
-
-CORE_ADDR
-i386_linux_sigtramp_saved_pc (struct frame_info *frame)
-{
- CORE_ADDR addr;
- addr = i386_linux_sigcontext_addr (frame);
- return read_memory_integer (addr + LINUX_SIGCONTEXT_PC_OFFSET, 4);
-}
-
-/* Offset to saved SP in sigcontext, from <asm/sigcontext.h>. */
-#define LINUX_SIGCONTEXT_SP_OFFSET (28)
-
-/* Assuming FRAME is for a Linux sigtramp routine, return the saved
- stack pointer. */
-
-CORE_ADDR
-i386_linux_sigtramp_saved_sp (struct frame_info *frame)
-{
- CORE_ADDR addr;
- addr = i386_linux_sigcontext_addr (frame);
- return read_memory_integer (addr + LINUX_SIGCONTEXT_SP_OFFSET, 4);
-}
-
-/* Immediately after a function call, return the saved pc. */
-
-CORE_ADDR
-i386_linux_saved_pc_after_call (struct frame_info *frame)
-{
- if (frame->signal_handler_caller)
- return i386_linux_sigtramp_saved_pc (frame);
-
- return read_memory_integer (read_register (SP_REGNUM), 4);
-}
-
-
/* Register that we are able to handle Linux ELF core file formats. */
static struct core_fns linux_elf_core_fns =
diff --git a/gdb/i386-linux-tdep.c b/gdb/i386-linux-tdep.c
new file mode 100644
index 0000000..38d6bcb
--- /dev/null
+++ b/gdb/i386-linux-tdep.c
@@ -0,0 +1,281 @@
+/* Target-dependent code for Linux running on i386's, for GDB.
+ Copyright (C) 2000 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include "defs.h"
+#include "gdbcore.h"
+#include "frame.h"
+#include "value.h"
+
+
+/* Recognizing signal handler frames. */
+
+/* Linux has two flavors of signals. Normal signal handlers, and
+ "realtime" (RT) signals. The RT signals can provide additional
+ information to the signal handler if the SA_SIGINFO flag is set
+ when establishing a signal handler using `sigaction'. It is not
+ unlikely that future versions of Linux will support SA_SIGINFO for
+ normal signals too. */
+
+/* When the i386 Linux kernel calls a signal handler and the
+ SA_RESTORER flag isn't set, the return address points to a bit of
+ code on the stack. This function returns whether the PC appears to
+ be within this bit of code.
+
+ The instruction sequence for normal signals is
+ pop %eax
+ mov $0x77,%eax
+ int $0x80
+ or 0x58 0xb8 0x77 0x00 0x00 0x00 0xcd 0x80.
+
+ Checking for the code sequence should be somewhat reliable, because
+ the effect is to call the system call sigreturn. This is unlikely
+ to occur anywhere other than a signal trampoline.
+
+ It kind of sucks that we have to read memory from the process in
+ order to identify a signal trampoline, but there doesn't seem to be
+ any other way. The IN_SIGTRAMP macro in tm-linux.h arranges to
+ only call us if no function name could be identified, which should
+ be the case since the code is on the stack.
+
+ Detection of signal trampolines for handlers that set the
+ SA_RESTORER flag is in general not possible. Unfortunately this is
+ what the GNU C Library has been doing for quite some time now.
+ However, as of version 2.1.2, the GNU C Library uses signal
+ trampolines (named __restore and __restore_rt) that are identical
+ 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)
+
+static const unsigned char linux_sigtramp_code[] =
+{
+ LINUX_SIGTRAMP_INSN0, /* pop %eax */
+ LINUX_SIGTRAMP_INSN1, 0x77, 0x00, 0x00, 0x00, /* mov $0x77,%eax */
+ LINUX_SIGTRAMP_INSN2, 0x80 /* int $0x80 */
+};
+
+#define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
+
+/* If PC is in a sigtramp routine, return the address of the start of
+ the routine. Otherwise, return 0. */
+
+static CORE_ADDR
+i386_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 three 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;
+
+ if (buf[0] != LINUX_SIGTRAMP_INSN0)
+ {
+ int adjust;
+
+ switch (buf[0])
+ {
+ case LINUX_SIGTRAMP_INSN1:
+ adjust = LINUX_SIGTRAMP_OFFSET1;
+ break;
+ case LINUX_SIGTRAMP_INSN2:
+ adjust = LINUX_SIGTRAMP_OFFSET2;
+ break;
+ default:
+ return 0;
+ }
+
+ pc -= adjust;
+
+ if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
+ return 0;
+ }
+
+ if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
+ return 0;
+
+ return pc;
+}
+
+/* This function does the same for RT signals. Here the instruction
+ sequence is
+ 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)
+
+static const unsigned char linux_rt_sigtramp_code[] =
+{
+ LINUX_RT_SIGTRAMP_INSN0, 0xad, 0x00, 0x00, 0x00, /* mov $0xad,%eax */
+ LINUX_RT_SIGTRAMP_INSN1, 0x80 /* int $0x80 */
+};
+
+#define LINUX_RT_SIGTRAMP_LEN (sizeof linux_rt_sigtramp_code)
+
+/* If PC is in a RT sigtramp routine, return the address of the start
+ of the routine. Otherwise, return 0. */
+
+static CORE_ADDR
+i386_linux_rt_sigtramp_start (CORE_ADDR pc)
+{
+ unsigned char buf[LINUX_RT_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_RT_SIGTRAMP_LEN) != 0)
+ return 0;
+
+ if (buf[0] != LINUX_RT_SIGTRAMP_INSN0)
+ {
+ if (buf[0] != LINUX_RT_SIGTRAMP_INSN1)
+ return 0;
+
+ pc -= LINUX_RT_SIGTRAMP_OFFSET1;
+
+ if (read_memory_nobpt (pc, (char *) buf, LINUX_RT_SIGTRAMP_LEN) != 0)
+ return 0;
+ }
+
+ if (memcmp (buf, linux_rt_sigtramp_code, LINUX_RT_SIGTRAMP_LEN) != 0)
+ return 0;
+
+ return pc;
+}
+
+/* Return whether PC is in a Linux sigtramp routine. */
+
+int
+i386_linux_in_sigtramp (CORE_ADDR pc, char *name)
+{
+ if (name)
+ return STREQ ("__restore", name) || STREQ ("__restore_rt", name);
+
+ return (i386_linux_sigtramp_start (pc) != 0
+ || i386_linux_rt_sigtramp_start (pc) != 0);
+}
+
+/* Assuming FRAME is for a Linux sigtramp routine, return the address
+ of the associated sigcontext structure. */
+
+CORE_ADDR
+i386_linux_sigcontext_addr (struct frame_info *frame)
+{
+ CORE_ADDR pc;
+
+ pc = i386_linux_sigtramp_start (frame->pc);
+ if (pc)
+ {
+ CORE_ADDR sp;
+
+ if (frame->next)
+ /* 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 frame->next->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 == frame->pc)
+ return sp + 4;
+ return sp;
+ }
+
+ pc = i386_linux_rt_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. A pointer to the user context is passed
+ as the third argument to the signal handler. */
+ return read_memory_integer (frame->next->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;
+ }
+
+ error ("Couldn't recognize signal trampoline.");
+ return 0;
+}
+
+/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>. */
+#define LINUX_SIGCONTEXT_PC_OFFSET (56)
+
+/* Assuming FRAME is for a Linux sigtramp routine, return the saved
+ program counter. */
+
+CORE_ADDR
+i386_linux_sigtramp_saved_pc (struct frame_info *frame)
+{
+ CORE_ADDR addr;
+ addr = i386_linux_sigcontext_addr (frame);
+ return read_memory_integer (addr + LINUX_SIGCONTEXT_PC_OFFSET, 4);
+}
+
+/* Offset to saved SP in sigcontext, from <asm/sigcontext.h>. */
+#define LINUX_SIGCONTEXT_SP_OFFSET (28)
+
+/* Assuming FRAME is for a Linux sigtramp routine, return the saved
+ stack pointer. */
+
+CORE_ADDR
+i386_linux_sigtramp_saved_sp (struct frame_info *frame)
+{
+ CORE_ADDR addr;
+ addr = i386_linux_sigcontext_addr (frame);
+ return read_memory_integer (addr + LINUX_SIGCONTEXT_SP_OFFSET, 4);
+}
+
+/* Immediately after a function call, return the saved pc. */
+
+CORE_ADDR
+i386_linux_saved_pc_after_call (struct frame_info *frame)
+{
+ if (frame->signal_handler_caller)
+ return i386_linux_sigtramp_saved_pc (frame);
+
+ return read_memory_integer (read_register (SP_REGNUM), 4);
+}