kgdb: Remove first_entry for kgdb

There are two ways to run into handle_exception, run command 'kgdb' and
encounter a breakpoint which triggers exception handling.

The origin source code only saves regs when first run command 'kgdb'.
Take the following for example, When run 'kgdb', regs is saved to entry_regs.
When run 'bootz', regs is not saved. However, if we set a breakpoint, then
continue. When breakpoint is reached, run `quit`, and Now return to the
instruction which follows kgdb, but not bootz.This may cause errors. So,
save regs for each handle_exception call to return to the correct place.
Example:
Target      |    Host
=>kgdb      |    (gdb)b bootz
            |    (gdb)c
=>bootz     |
            |    (gdb)Here stop because of breakpoint
            |    (gdb)q

Signed-off-by: Peng Fan <van.freenix@gmail.com>

diff --git a/common/kgdb.c b/common/kgdb.c
index 8a621ad1fc755aaa4b7313e01c29348ec6f5bcd2..d357463695f3c0cc85dd2b88ce2504a7312dd97a 100644 (file)
--- a/common/kgdb.c
+++ b/common/kgdb.c
@@ -103,7 +103,7 @@ static char remcomOutBuffer[BUFMAX];
 static char remcomRegBuffer[BUFMAX];
 
 static int initialized = 0;
-static int kgdb_active = 0, first_entry = 1;
+static int kgdb_active;
 static struct pt_regs entry_regs;
 static long error_jmp_buf[BUFMAX/2];
 static int longjmp_on_fault = 0;
@@ -348,16 +348,7 @@ handle_exception (struct pt_regs *regs)
 
        kgdb_enter(regs, &kd);
 
-       if (first_entry) {
-               /*
-                * the first time we enter kgdb, we save the processor
-                * state so that we can return to the monitor if the
-                * remote end quits gdb (or at least, tells us to quit
-                * with the 'k' packet)
-                */
-               entry_regs = *regs;
-               first_entry = 0;
-       }
+       entry_regs = *regs;
 
        ptr = remcomOutBuffer;
 
@@ -459,7 +450,6 @@ handle_exception (struct pt_regs *regs)
                case 'k':    /* kill the program, actually return to monitor */
                        kd.extype = KGDBEXIT_KILL;
                        *regs = entry_regs;
-                       first_entry = 1;
                        goto doexit;
 
                case 'C':    /* CSS  continue with signal SS */