"r40", "r41", "r42", "r43", "r44", "r45", "r46", "r47",
"r48", "r49", "r50", "r51", "r52", "tp", "sp", "lr",
"sn", "idn0", "idn1", "udn0", "udn1", "udn2", "udn3", "zero",
- "pc"
+ "pc", "faultnum",
};
if (regnum < 0 || regnum >= TILEGX_NUM_REGS)
return 0;
}
+/* by assigning the 'faultnum' reg in kernel pt_regs with this value,
+ kernel do_signal will not check r0. see tilegx kernel/signal.c
+ for details. */
+#define INT_SWINT_1_SIGRETURN (~0)
+
+/* Implement the "write_pc" gdbarch method. */
+
+static void
+tilegx_write_pc (struct regcache *regcache, CORE_ADDR pc)
+{
+ regcache_cooked_write_unsigned (regcache, TILEGX_PC_REGNUM, pc);
+
+ /* We must be careful with modifying the program counter. If we
+ just interrupted a system call, the kernel might try to restart
+ it when we resume the inferior. On restarting the system call,
+ the kernel will try backing up the program counter even though it
+ no longer points at the system call. This typically results in a
+ SIGSEGV or SIGILL. We can prevent this by writing INT_SWINT_1_SIGRETURN
+ in the "faultnum" pseudo-register.
+
+ Note that "faultnum" is saved when setting up a dummy call frame.
+ This means that it is properly restored when that frame is
+ popped, and that the interrupted system call will be restarted
+ when we resume the inferior on return from a function call from
+ within GDB. In all other cases the system call will not be
+ restarted. */
+ regcache_cooked_write_unsigned (regcache, TILEGX_FAULTNUM_REGNUM,
+ INT_SWINT_1_SIGRETURN);
+}
+
/* This is the implementation of gdbarch method breakpoint_from_pc. */
static const unsigned char *
{
if (regno >= 0 && regno < TILEGX_NUM_EASY_REGS)
return 0;
- else if (regno == TILEGX_PC_REGNUM)
+ else if (regno == TILEGX_PC_REGNUM
+ || regno == TILEGX_FAULTNUM_REGNUM)
return 0;
else
return 1;
/* These values and methods are used when gdb calls a target function. */
set_gdbarch_push_dummy_call (gdbarch, tilegx_push_dummy_call);
+ set_gdbarch_write_pc (gdbarch, tilegx_write_pc);
set_gdbarch_breakpoint_from_pc (gdbarch, tilegx_breakpoint_from_pc);
set_gdbarch_return_value (gdbarch, tilegx_return_value);