* 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.
This commit is contained in:
Jim Blandy
parent
58a2c44a26
commit
e7ee86a99a
@ -1,3 +1,25 @@
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2000-03-20 Jim Blandy <jimb@redhat.com>
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* i386-linux-nat.c: No need to #include "frame.h" any more.
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(LINUX_SIGTRAMP_INSN0, LINUX_SIGTRAMP_OFFSET0,
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LINUX_SIGTRAMP_INSN1, LINUX_SIGTRAMP_OFFSET1,
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LINUX_SIGTRAMP_INSN2, LINUX_SIGTRAMP_OFFSET2, linux_sigtramp_code,
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LINUX_SIGTRAMP_LEN, i386_linux_sigtramp_start,
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LINUX_RT_SIGTRAMP_INSN0, LINUX_RT_SIGTRAMP_OFFSET0,
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LINUX_RT_SIGTRAMP_INSN1, LINUX_RT_SIGTRAMP_OFFSET1,
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linux_rt_sigtramp_code, LINUX_RT_SIGTRAMP_LEN,
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i386_linux_rt_sigtramp_start, i386_linux_in_sigtramp,
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i386_linux_sigcontext_addr, LINUX_SIGCONTEXT_PC_OFFSET,
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i386_linux_sigtramp_saved_pc, LINUX_SIGCONTEXT_SP_OFFSET,
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i386_linux_sigtramp_saved_sp): Deleted. Folks rightly pointed
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out that these are target-dependent, and useful in non-native
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configurations. Moved to...
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* i386-linux-tdep.c: ... Here, a new file.
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* Makefile.in (ALLDEPFILES): Add i386-linux-tdep.c.
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(i386-linux-tdep.o): New rule.
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(i386-linux-nat.o): We no longer depend on frame.h.
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* config/i386/linux.mt (TDEPFILES): Add i386-linux-tdep.o.
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2000-03-04 Eli Zaretskii <eliz@is.elta.co.il>
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* event-loop.c (top-level) [NO_FD_SET]: Deprecate this branch.
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@ -64,26 +86,6 @@ Mon Mar 20 17:33:32 2000 Andrew Cagney <cagney@b1.cygnus.com>
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* gdb_wait.h (WSETSTOP): Pass the appropriate number of arguments
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to W_STOPCODE.
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* i386-linux-nat.c: No need to #include "frame.h" any more.
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(LINUX_SIGTRAMP_INSN0, LINUX_SIGTRAMP_OFFSET0,
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LINUX_SIGTRAMP_INSN1, LINUX_SIGTRAMP_OFFSET1,
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LINUX_SIGTRAMP_INSN2, LINUX_SIGTRAMP_OFFSET2, linux_sigtramp_code,
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LINUX_SIGTRAMP_LEN, i386_linux_sigtramp_start,
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LINUX_RT_SIGTRAMP_INSN0, LINUX_RT_SIGTRAMP_OFFSET0,
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LINUX_RT_SIGTRAMP_INSN1, LINUX_RT_SIGTRAMP_OFFSET1,
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linux_rt_sigtramp_code, LINUX_RT_SIGTRAMP_LEN,
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i386_linux_rt_sigtramp_start, i386_linux_in_sigtramp,
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i386_linux_sigcontext_addr, LINUX_SIGCONTEXT_PC_OFFSET,
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i386_linux_sigtramp_saved_pc, LINUX_SIGCONTEXT_SP_OFFSET,
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i386_linux_sigtramp_saved_sp): Deleted. Folks rightly pointed
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out that these are target-dependent, and useful in non-native
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configurations. Moved to...
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* i386-linux-tdep.c: ... Here, a new file.
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* Makefile.in (ALLDEPFILES): Add i386-linux-tdep.c.
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(i386-linux-tdep.o): New rule.
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(i386-linux-nat.o): We no longer depend on frame.h.
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* config/i386/linux.mt (TDEPFILES): Add i386-linux-tdep.o.
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* solib.c (solib_add): Delete debugging code.
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2000-03-17 Mark Kettenis <kettenis@gnu.org>
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@ -1063,6 +1063,7 @@ ALLDEPFILES = 29k-share/udi/udip2soc.c 29k-share/udi/udr.c \
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i386-tdep.c i386b-nat.c i386mach-nat.c i386v-nat.c i386-linux-nat.c \
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i386aix-nat.c i386m3-nat.c i386v4-nat.c i386ly-tdep.c \
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i387-tdep.c \
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i386-linux-tdep.c \
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i960-tdep.c \
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infptrace.c inftarg.c irix4-nat.c irix5-nat.c isi-xdep.c \
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lynx-nat.c m3-nat.c \
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@ -1395,7 +1396,10 @@ i386v-nat.o: i386v-nat.c $(floatformat_h) $(defs_h) $(gdbcore_h) \
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$(inferior_h) language.h target.h
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i386-linux-nat.o: i386-linux-nat.c $(defs_h) $(inferior_h) $(gdbcore_h) \
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$(symtab_h) $(frame_h) symfile.h objfiles.h
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$(symtab_h) symfile.h objfiles.h
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i386-linux-tdep.o: i386-linux-tdep.c $(defs_h) $(gdbcore_h) $(frame_h) \
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$(value_h)
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i386v4-nat.o: i386v4-nat.c $(defs_h)
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@ -1,5 +1,5 @@
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# Target: Intel 386 running GNU/Linux
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TDEPFILES= i386-tdep.o i387-tdep.o
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TDEPFILES= i386-tdep.o i386-linux-tdep.o i387-tdep.o
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TM_FILE= tm-linux.h
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GDBSERVER_DEPFILES= low-linux.o
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@ -23,7 +23,6 @@
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/* For i386_linux_skip_solib_resolver. */
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#include "symtab.h"
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#include "frame.h"
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#include "symfile.h"
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#include "objfiles.h"
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@ -1043,263 +1042,6 @@ i386_linux_skip_solib_resolver (CORE_ADDR pc)
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return 0;
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}
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/* Recognizing signal handler frames. */
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/* Linux has two flavors of signals. Normal signal handlers, and
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"realtime" (RT) signals. The RT signals can provide additional
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information to the signal handler if the SA_SIGINFO flag is set
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when establishing a signal handler using `sigaction'. It is not
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unlikely that future versions of Linux will support SA_SIGINFO for
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normal signals too. */
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/* When the i386 Linux kernel calls a signal handler and the
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SA_RESTORER flag isn't set, the return address points to a bit of
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code on the stack. This function returns whether the PC appears to
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be within this bit of code.
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The instruction sequence for normal signals is
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pop %eax
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mov $0x77,%eax
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int $0x80
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or 0x58 0xb8 0x77 0x00 0x00 0x00 0xcd 0x80.
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Checking for the code sequence should be somewhat reliable, because
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the effect is to call the system call sigreturn. This is unlikely
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to occur anywhere other than a signal trampoline.
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It kind of sucks that we have to read memory from the process in
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order to identify a signal trampoline, but there doesn't seem to be
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any other way. The IN_SIGTRAMP macro in tm-linux.h arranges to
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only call us if no function name could be identified, which should
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be the case since the code is on the stack.
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Detection of signal trampolines for handlers that set the
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SA_RESTORER flag is in general not possible. Unfortunately this is
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what the GNU C Library has been doing for quite some time now.
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However, as of version 2.1.2, the GNU C Library uses signal
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trampolines (named __restore and __restore_rt) that are identical
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to the ones used by the kernel. Therefore, these trampolines are
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supported too. */
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#define LINUX_SIGTRAMP_INSN0 (0x58) /* pop %eax */
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#define LINUX_SIGTRAMP_OFFSET0 (0)
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#define LINUX_SIGTRAMP_INSN1 (0xb8) /* mov $NNNN,%eax */
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#define LINUX_SIGTRAMP_OFFSET1 (1)
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#define LINUX_SIGTRAMP_INSN2 (0xcd) /* int */
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#define LINUX_SIGTRAMP_OFFSET2 (6)
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static const unsigned char linux_sigtramp_code[] =
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{
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LINUX_SIGTRAMP_INSN0, /* pop %eax */
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LINUX_SIGTRAMP_INSN1, 0x77, 0x00, 0x00, 0x00, /* mov $0x77,%eax */
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LINUX_SIGTRAMP_INSN2, 0x80 /* int $0x80 */
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};
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#define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
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/* If PC is in a sigtramp routine, return the address of the start of
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the routine. Otherwise, return 0. */
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static CORE_ADDR
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i386_linux_sigtramp_start (CORE_ADDR pc)
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{
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unsigned char buf[LINUX_SIGTRAMP_LEN];
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/* We only recognize a signal trampoline if PC is at the start of
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one of the three instructions. We optimize for finding the PC at
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the start, as will be the case when the trampoline is not the
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first frame on the stack. We assume that in the case where the
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PC is not at the start of the instruction sequence, there will be
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a few trailing readable bytes on the stack. */
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if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
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return 0;
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if (buf[0] != LINUX_SIGTRAMP_INSN0)
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{
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int adjust;
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switch (buf[0])
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{
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case LINUX_SIGTRAMP_INSN1:
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adjust = LINUX_SIGTRAMP_OFFSET1;
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break;
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case LINUX_SIGTRAMP_INSN2:
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adjust = LINUX_SIGTRAMP_OFFSET2;
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break;
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default:
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return 0;
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}
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pc -= adjust;
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if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
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return 0;
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}
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if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
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return 0;
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return pc;
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}
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/* This function does the same for RT signals. Here the instruction
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sequence is
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mov $0xad,%eax
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int $0x80
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or 0xb8 0xad 0x00 0x00 0x00 0xcd 0x80.
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The effect is to call the system call rt_sigreturn. */
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#define LINUX_RT_SIGTRAMP_INSN0 (0xb8) /* mov $NNNN,%eax */
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#define LINUX_RT_SIGTRAMP_OFFSET0 (0)
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#define LINUX_RT_SIGTRAMP_INSN1 (0xcd) /* int */
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#define LINUX_RT_SIGTRAMP_OFFSET1 (5)
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static const unsigned char linux_rt_sigtramp_code[] =
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{
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LINUX_RT_SIGTRAMP_INSN0, 0xad, 0x00, 0x00, 0x00, /* mov $0xad,%eax */
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LINUX_RT_SIGTRAMP_INSN1, 0x80 /* int $0x80 */
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};
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#define LINUX_RT_SIGTRAMP_LEN (sizeof linux_rt_sigtramp_code)
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/* If PC is in a RT sigtramp routine, return the address of the start
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of the routine. Otherwise, return 0. */
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static CORE_ADDR
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i386_linux_rt_sigtramp_start (CORE_ADDR pc)
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{
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unsigned char buf[LINUX_RT_SIGTRAMP_LEN];
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/* We only recognize a signal trampoline if PC is at the start of
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one of the two instructions. We optimize for finding the PC at
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the start, as will be the case when the trampoline is not the
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first frame on the stack. We assume that in the case where the
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PC is not at the start of the instruction sequence, there will be
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a few trailing readable bytes on the stack. */
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if (read_memory_nobpt (pc, (char *) buf, LINUX_RT_SIGTRAMP_LEN) != 0)
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return 0;
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if (buf[0] != LINUX_RT_SIGTRAMP_INSN0)
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{
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if (buf[0] != LINUX_RT_SIGTRAMP_INSN1)
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return 0;
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pc -= LINUX_RT_SIGTRAMP_OFFSET1;
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if (read_memory_nobpt (pc, (char *) buf, LINUX_RT_SIGTRAMP_LEN) != 0)
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return 0;
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}
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if (memcmp (buf, linux_rt_sigtramp_code, LINUX_RT_SIGTRAMP_LEN) != 0)
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return 0;
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return pc;
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}
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/* Return whether PC is in a Linux sigtramp routine. */
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int
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i386_linux_in_sigtramp (CORE_ADDR pc, char *name)
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||||
{
|
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if (name)
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||||
return STREQ ("__restore", name) || STREQ ("__restore_rt", name);
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||||
return (i386_linux_sigtramp_start (pc) != 0
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|| i386_linux_rt_sigtramp_start (pc) != 0);
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||||
}
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|
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/* Assuming FRAME is for a Linux sigtramp routine, return the address
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||||
of the associated sigcontext structure. */
|
||||
|
||||
CORE_ADDR
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||||
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. */
|
||||
|
||||
|
||||
281
gdb/i386-linux-tdep.c
Normal file
281
gdb/i386-linux-tdep.c
Normal file
@ -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);
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user