diff options
Diffstat (limited to 'sysdeps/sparc/__longjmp.S')
| -rw-r--r-- | sysdeps/sparc/__longjmp.S | 63 |
1 files changed, 37 insertions, 26 deletions
diff --git a/sysdeps/sparc/__longjmp.S b/sysdeps/sparc/__longjmp.S index adff06e349..38bc7bbac8 100644 --- a/sysdeps/sparc/__longjmp.S +++ b/sysdeps/sparc/__longjmp.S @@ -1,4 +1,4 @@ -/* Copyright (C) 1991, 1993 Free Software Foundation, Inc. +/* Copyright (C) 1991, 1993, 1996 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -17,31 +17,42 @@ not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <sysdep.h> -#ifdef __svr4__ -#include <sys/trap.h> -#else -#include <machine/trap.h> -#endif -/* NOTE: This code depends on the definition of `__jmp_buf' in <jmp_buf.h>. */ +#include <jmp_buf.h> +#define ENV(reg) [%g1 + (reg * 4)] ENTRY (__longjmp) - /* Do a "flush register windows trap". The trap handler in the - kernel writes all the register windows to their stack slots, and - marks them all as invalid (needing to be sucked up from the - stack when used). This ensures that all information needed to - unwind to these callers is in memory, not in the register - windows. */ - ta ST_FLUSH_WINDOWS - ld [%o0], %o7 /* Return PC. */ - ld [%o0 + 4], %fp /* Saved SP. */ - sub %fp, 64, %sp /* Allocate a register save area. */ - - /* if (%o1 == 0) %o1 = 1; */ - tst %o1 - be,a Ldone - mov 1, %o1 - -Ldone: retl - /* On the way out, put the return value in %o0. */ - restore %o1, 0, %o0 + /* Store our arguments in global registers so we can still + use them while unwinding frames and their register windows. */ + mov %o0, %g1 /* ENV in %g1 */ + orcc %o1, %g0, %g6 /* VAL in %g6 */ + be,a 0f /* Branch if zero; else skip delay slot. */ + mov 1, %g6 /* Delay slot only hit if zero: VAL = 1. */ +0: + + /* Cache target FP in register %g7. */ + ld ENV (JB_FP), %g7 + + /* Now we will loop, unwinding the register windows up the stack + until the restored %fp value matches the target value in %g7. */ + +loop: cmp %fp, %g7 /* Have we reached the target frame? */ + bl,a loop /* Loop while current fp is below target. */ + restore /* Unwind register window in delay slot. */ + be,a found /* Better have hit it exactly. */ + ld ENV (JB_SP), %o0 /* Delay slot: extract target SP. */ + +bogus: /* Get here only if the jmp_buf or stack is clobbered. */ + call C_SYMBOL_NAME (abort) + nop + unimp 0 + +found: /* We have unwound register windows so %fp matches the target. */ + cmp %o0, %sp /* Check jmp_buf SP vs register window. */ + bge,a sp_ok /* Saved must not be deeper than register. */ + mov %o0, %sp /* OK, install new SP. */ + b,a bogus /* Bogus, we lose. */ + +sp_ok: ld ENV (JB_PC), %o0 /* Extract target return PC. */ + jmp %o0 + 8 /* Return there. */ + mov %g6, %o0 /* Delay slot: set return value. */ |