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-rw-r--r--gdb/i386-nlmstub.c111
1 files changed, 65 insertions, 46 deletions
diff --git a/gdb/i386-nlmstub.c b/gdb/i386-nlmstub.c
index c9bcaf1..5b1bed6 100644
--- a/gdb/i386-nlmstub.c
+++ b/gdb/i386-nlmstub.c
@@ -472,6 +472,9 @@ getpacket (buffer)
}
while (checksum != xmitcsum);
+ if (remote_debug)
+ ConsolePrintf ("Received packet \"%s\"\r\n", buffer);
+
return 1;
}
@@ -486,6 +489,9 @@ putpacket (buffer)
int count;
int ch;
+ if (remote_debug)
+ ConsolePrintf ("Sending packet \"%s\"\r\n", buffer);
+
/* $<packet info>#<checksum>. */
do
{
@@ -526,22 +532,19 @@ debug_error (format, parm)
char *parm;
{
if (remote_debug)
- fprintf (stderr, format, parm);
+ {
+ fprintf (stderr, format, parm);
+ fprintf (stderr, "\n");
+ }
}
-/* Address of a routine to RTE to if we get a memory fault. */
-static volatile void (*mem_fault_routine)() = NULL;
+/* This is set if we could get a memory access fault. */
+static int mem_may_fault;
/* Indicate to caller of mem2hex or hex2mem that there has been an
error. */
static volatile int mem_err = 0;
-static void
-set_mem_err ()
-{
- mem_err = 1;
-}
-
/* These are separate functions so that they are so short and sweet
that the compiler won't save any registers (if there is a fault
to mem_fault, they won't get restored, so there better not be any
@@ -562,6 +565,18 @@ set_char (addr, val)
*addr = val;
}
+/* This bit of assembly language just returns from a function. If a
+ memory error occurs within get_char or set_char, the debugger
+ handler points EIP at these instructions to get out. */
+
+extern void just_return ();
+asm (".globl just_return");
+asm (".globl _just_return");
+asm ("just_return:");
+asm ("_just_return:");
+asm ("leave");
+asm ("ret");
+
/* convert the memory pointed to by mem into hex, placing result in buf */
/* return a pointer to the last char put in buf (null) */
/* If MAY_FAULT is non-zero, then we should set mem_err in response to
@@ -577,8 +592,7 @@ mem2hex (mem, buf, count, may_fault)
int i;
unsigned char ch;
- if (may_fault)
- mem_fault_routine = set_mem_err;
+ mem_may_fault = may_fault;
for (i = 0; i < count; i++)
{
ch = get_char (mem++);
@@ -588,8 +602,7 @@ mem2hex (mem, buf, count, may_fault)
*buf++ = hexchars[ch % 16];
}
*buf = 0;
- if (may_fault)
- mem_fault_routine = NULL;
+ mem_may_fault = 0;
return(buf);
}
@@ -606,8 +619,7 @@ hex2mem (buf, mem, count, may_fault)
int i;
unsigned char ch;
- if (may_fault)
- mem_fault_routine = set_mem_err;
+ mem_may_fault = may_fault;
for (i=0;i<count;i++)
{
ch = hex(*buf++) << 4;
@@ -616,8 +628,7 @@ hex2mem (buf, mem, count, may_fault)
if (may_fault && mem_err)
return (mem);
}
- if (may_fault)
- mem_fault_routine = NULL;
+ mem_may_fault = 0;
return(mem);
}
@@ -691,7 +702,6 @@ static LONG
handle_exception (T_StackFrame *old_frame)
{
T_TSS_StackFrame *frame = (T_TSS_StackFrame *) old_frame;
- int first = 0;
int sigval;
int addr, length;
char * ptr;
@@ -723,6 +733,14 @@ handle_exception (T_StackFrame *old_frame)
return RETURN_TO_PROGRAM;
}
+ /* After we've reached the initial breakpoint, reset it. */
+ if (frame->ExceptionEIP == (LONG) handle->LDInitializationProcedure + 1
+ && *(unsigned char *) handle->LDInitializationProcedure == 0xcc)
+ {
+ *(char *) handle->LDInitializationProcedure = first_insn;
+ frame->ExceptionEIP = (LONG) handle->LDInitializationProcedure;
+ }
+
/* Pass some events on to the next debugger, in case it will handle
them. */
if (frame->ExceptionNumber == ENTER_DEBUGGER_EVENT
@@ -735,14 +753,26 @@ handle_exception (T_StackFrame *old_frame)
&& frame->ExceptionNumber > 31)
return RETURN_TO_PROGRAM;
- /* Reset the initial breakpoint if necessary. */
- if (frame->ExceptionNumber == 3
- && frame->ExceptionEIP == (LONG) handle->LDInitializationProcedure + 1
- && *(unsigned char *) handle->LDInitializationProcedure == 0xcc)
+ /* If we get a GP fault, and mem_may_fault is set, and the
+ instruction pointer is near set_char or get_char, then we caused
+ the fault ourselves accessing an illegal memory location. */
+ if (mem_may_fault
+ && (frame->ExceptionNumber == 11
+ || frame->ExceptionNumber == 13
+ || frame->ExceptionNumber == 14)
+ && ((frame->ExceptionEIP >= (long) &set_char
+ && frame->ExceptionEIP < (long) &set_char + 50)
+ || (frame->ExceptionEIP >= (long) &get_char
+ && frame->ExceptionEIP < (long) &get_char + 50)))
{
- *(char *) handle->LDInitializationProcedure = first_insn;
- frame->ExceptionEIP = (LONG) handle->LDInitializationProcedure;
- first = 1;
+ mem_err = 1;
+ /* Point the instruction pointer at an assembly language stub
+ which just returns from the function. */
+ frame->ExceptionEIP = (long) &just_return;
+ /* Keep going. This will act as though it returned from
+ set_char or get_char. The calling routine will check
+ mem_err, and do the right thing. */
+ return RETURN_TO_PROGRAM;
}
/* FIXME: How do we know that this exception has anything to do with
@@ -764,18 +794,13 @@ handle_exception (T_StackFrame *old_frame)
else
{
sigval = computeSignal (frame->ExceptionNumber);
- remcomOutBuffer[0] = 'S';
+ remcomOutBuffer[0] = 'N';
remcomOutBuffer[1] = hexchars[sigval >> 4];
remcomOutBuffer[2] = hexchars[sigval % 16];
- remcomOutBuffer[3] = 0;
- if (first)
- {
- remcomOutBuffer[0] = 'N';
- sprintf (remcomOutBuffer + 3, "0x%x;0x%x;0x%x",
- handle->LDCodeImageOffset,
- handle->LDDataImageOffset,
- handle->LDDataImageOffset + handle->LDDataImageLength);
- }
+ sprintf (remcomOutBuffer + 3, "0x%x;0x%x;0x%x",
+ handle->LDCodeImageOffset,
+ handle->LDDataImageOffset,
+ handle->LDDataImageOffset + handle->LDDataImageLength);
}
if (! putpacket(remcomOutBuffer))
@@ -798,19 +823,13 @@ handle_exception (T_StackFrame *old_frame)
{
case '?':
sigval = computeSignal (frame->ExceptionNumber);
- remcomOutBuffer[0] = 'S';
+ remcomOutBuffer[0] = 'N';
remcomOutBuffer[1] = hexchars[sigval >> 4];
remcomOutBuffer[2] = hexchars[sigval % 16];
- remcomOutBuffer[3] = 0;
- if (first)
- {
- remcomOutBuffer[0] = 'N';
- sprintf (remcomOutBuffer + 3, "0x%x;0x%x;0x%x",
- handle->LDCodeImageOffset,
- handle->LDDataImageOffset,
- (handle->LDDataImageOffset
- + handle->LDDataImageLength));
- }
+ sprintf (remcomOutBuffer + 3, "0x%x;0x%x;0x%x",
+ handle->LDCodeImageOffset,
+ handle->LDDataImageOffset,
+ handle->LDDataImageOffset + handle->LDDataImageLength);
break;
case 'd':
remote_debug = !(remote_debug); /* toggle debug flag */
generated by cgit v1.1 at 2024-12-22 05:58:44 +0000