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Signal trampoline handling on m68k-linux
- From: Andreas Schwab <schwab at suse dot de>
- To: gdb-patches at sources dot redhat dot com
- Date: Tue, 26 Feb 2002 23:13:12 +0100
- Subject: Signal trampoline handling on m68k-linux
This updates the recognition of signal trampolines on m68k-linux.
Committed.
Andreas.
2002-02-26 Andreas Schwab <schwab@suse.de>
* config/m68k/tm-linux.h (FRAME_SAVED_PC): Define as
m68k_linux_frame_saved_pc.
(IN_SIGTRAMP): Define as m68k_linux_in_sigtramp instead of
in_sigtramp.
(SIGCONTEXT_PC_OFFSET): Remove.
* m68klinux-nat.c (m68k_linux_frame_saved_pc,
m68k_linux_sigtramp_saved_pc): New functions.
(IS_SIGTRAMP, IS_RT_SIGTRAMP): Define.
(SIGCONTEXT_PC_OFFSET): Moved here from config/m68k/tm-linux.h.
(UCONTEXT_PC_OFFSET): Define.
(m68k_linux_in_sigtramp): Renamed from in_sigtramp, handle both
non-RT and RT signal trampolines.
Index: gdb/m68klinux-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/m68klinux-nat.c,v
retrieving revision 1.9
diff -u -a -r1.9 gdb/m68klinux-nat.c
--- gdb/m68klinux-nat.c 2002/02/24 22:14:33 1.9
+++ gdb/m68klinux-nat.c 2002/02/26 21:55:15
@@ -594,40 +594,102 @@
return (sizeof (struct user));
}
-/* Return non-zero if PC points into the signal trampoline. */
+/* Check whether insn1 and insn2 are parts of a signal trampoline. */
+#define IS_SIGTRAMP(insn1, insn2) \
+ (/* addaw #20,sp; moveq #119,d0; trap #0 */ \
+ (insn1 == 0xdefc0014 && insn2 == 0x70774e40) \
+ /* moveq #119,d0; trap #0 */ \
+ || insn1 == 0x70774e40)
+
+#define IS_RT_SIGTRAMP(insn1, insn2) \
+ (/* movel #173,d0; trap #0 */ \
+ (insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \
+ /* moveq #82,d0; notb d0; trap #0 */ \
+ || (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40))
+
+/* Return non-zero if PC points into the signal trampoline. For the sake
+ of m68k_linux_frame_saved_pc we also distinguish between non-RT and RT
+ signal trampolines. */
+
int
-in_sigtramp (CORE_ADDR pc)
+m68k_linux_in_sigtramp (CORE_ADDR pc)
{
CORE_ADDR sp;
- char buf[TARGET_SHORT_BIT / TARGET_CHAR_BIT];
- int insn;
+ char buf[12];
+ unsigned long insn0, insn1, insn2;
- sp = read_register (SP_REGNUM);
- if (pc - 2 < sp)
+ if (read_memory_nobpt (pc - 4, buf, sizeof (buf)))
return 0;
+ insn1 = extract_unsigned_integer (buf + 4, 4);
+ insn2 = extract_unsigned_integer (buf + 8, 4);
+ if (IS_SIGTRAMP (insn1, insn2))
+ return 1;
+ if (IS_RT_SIGTRAMP (insn1, insn2))
+ return 2;
- if (read_memory_nobpt (pc, buf, sizeof (buf)))
- return 0;
- insn = extract_unsigned_integer (buf, sizeof (buf));
- if (insn == 0xdefc /* addaw #,sp */
- || insn == 0x7077 /* moveq #119,d0 */
- || insn == 0x4e40 /* trap #0 */
- || insn == 0x203c /* movel #,d0 */ )
+ insn0 = extract_unsigned_integer (buf, 4);
+ if (IS_SIGTRAMP (insn0, insn1))
return 1;
+ if (IS_RT_SIGTRAMP (insn0, insn1))
+ return 2;
- if (read_memory_nobpt (pc - 2, buf, sizeof (buf)))
- return 0;
- insn = extract_unsigned_integer (buf, sizeof (buf));
- if (insn == 0xdefc /* addaw #,sp */
- || insn == 0x7077 /* moveq #119,d0 */
- || insn == 0x4e40 /* trap #0 */
- || insn == 0x203c /* movel #,d0 */ )
+ insn0 = (insn0 << 16) | (insn1 >> 16);
+ insn1 = (insn1 << 16) | (insn2 >> 16);
+ if (IS_SIGTRAMP (insn0, insn1))
return 1;
+ if (IS_RT_SIGTRAMP (insn0, insn1))
+ return 2;
return 0;
}
+/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>. */
+#define SIGCONTEXT_PC_OFFSET 26
+
+/* Offset to saved PC in ucontext, from <asm/ucontext.h>. */
+#define UCONTEXT_PC_OFFSET 88
+
+/* Get saved user PC for sigtramp from sigcontext or ucontext. */
+
+static CORE_ADDR
+m68k_linux_sigtramp_saved_pc (struct frame_info *frame)
+{
+ CORE_ADDR sigcontext_addr;
+ char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
+ int ptrbytes = TARGET_PTR_BIT / TARGET_CHAR_BIT;
+ int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT;
+
+ /* Get sigcontext address, it is the third parameter on the stack. */
+ if (frame->next)
+ sigcontext_addr = read_memory_integer (FRAME_ARGS_ADDRESS (frame->next)
+ + FRAME_ARGS_SKIP
+ + sigcontext_offs,
+ ptrbytes);
+ else
+ sigcontext_addr = read_memory_integer (read_register (SP_REGNUM)
+ + sigcontext_offs,
+ ptrbytes);
+
+ /* Don't cause a memory_error when accessing sigcontext in case the
+ stack layout has changed or the stack is corrupt. */
+ if (m68k_linux_in_sigtramp (frame->pc) == 2)
+ target_read_memory (sigcontext_addr + UCONTEXT_PC_OFFSET, buf, ptrbytes);
+ else
+ target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes);
+ return extract_unsigned_integer (buf, ptrbytes);
+}
+
+/* Return the saved program counter for FRAME. */
+
+CORE_ADDR
+m68k_linux_frame_saved_pc (struct frame_info *frame)
+{
+ if (frame->signal_handler_caller)
+ return m68k_linux_sigtramp_saved_pc (frame);
+
+ return read_memory_integer (frame->frame + 4, 4);
+}
/* Register that we are able to handle GNU/Linux ELF core file
formats. */
Index: gdb/config/m68k/tm-linux.h
===================================================================
RCS file: /cvs/src/src/gdb/config/m68k/tm-linux.h,v
retrieving revision 1.6
diff -u -a -r1.6 gdb/config/m68k/tm-linux.h
--- gdb/config/m68k/tm-linux.h 2002/02/24 22:56:05 1.6
+++ gdb/config/m68k/tm-linux.h 2002/02/26 21:55:15
@@ -99,16 +99,9 @@
#define GET_LONGJMP_TARGET(ADDR) m68k_get_longjmp_target(ADDR)
-/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>. */
-#define SIGCONTEXT_PC_OFFSET 26
-
#undef FRAME_SAVED_PC
-#define FRAME_SAVED_PC(FRAME) \
- (((FRAME)->signal_handler_caller \
- ? sigtramp_saved_pc (FRAME) \
- : read_memory_integer ((FRAME)->frame + 4, 4)))
-
-extern CORE_ADDR sigtramp_saved_pc (struct frame_info *);
+#define FRAME_SAVED_PC(frame) m68k_linux_frame_saved_pc (frame)
+extern CORE_ADDR m68k_linux_frame_saved_pc (struct frame_info *);
-#define IN_SIGTRAMP(pc,name) in_sigtramp (pc)
-extern int in_sigtramp (CORE_ADDR pc);
+#define IN_SIGTRAMP(pc,name) m68k_linux_in_sigtramp (pc)
+extern int m68k_linux_in_sigtramp (CORE_ADDR pc);
--
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE GmbH, Deutschherrnstr. 15-19, D-90429 Nürnberg
Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
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