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Don't set up args on the stack; pass them in registers.

This commit is contained in:
Roland McGrath 1994-07-29 15:46:10 +00:00
parent 5736111e49
commit 840c5e79e3
1 changed files with 15 additions and 17 deletions
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32
sysdeps/mach/hurd/mips/trampoline.c
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@ -40,15 +40,6 @@ _hurd_setup_sighandler (int flags,
struct mips_thread_state *ts; struct mips_thread_state *ts;
void *sigsp; void *sigsp;
struct sigcontext *scp; struct sigcontext *scp;
struct
{
void *retaddr; /* Never used. */
__sighandler_t handler;
int signo;
int sigcode;
struct sigcontext *scp; /* Points to ctx, below. */
struct sigcontext ctx;
} *stackframe;
ts = state; ts = state;
@ -61,18 +52,16 @@ _hurd_setup_sighandler (int flags,
else else
sigsp = (char *) ts->r29; sigsp = (char *) ts->r29;
/* Push the arguments to call `trampoline' on the stack. */ /* Set up the sigcontext structure on the stack. This is all the stack
sigsp -= sizeof (*stackframe); needs, since the args are passed in registers (below). */
stackframe = sigsp; sigsp -= sizeof (*scp);
stackframe->handler = handler; scp = sigsp;
stackframe->signo = signo;
stackframe->sigcode = sigcode;
stackframe->scp = scp = &stackframe->ctx;
/* Set up the sigcontext from the current state of the thread. */ /* Set up the sigcontext from the current state of the thread. */
scp->sc_onstack = sigaltstack->ss_flags & SA_ONSTACK ? 1 : 0; scp->sc_onstack = sigaltstack->ss_flags & SA_ONSTACK ? 1 : 0;
scp->sc_gpr[2] = ts->r2;
scp->sc_gpr[16] = ts->r16; scp->sc_gpr[16] = ts->r16;
scp->sc_gpr[17] = ts->r17; scp->sc_gpr[17] = ts->r17;
scp->sc_gpr[18] = ts->r18; scp->sc_gpr[18] = ts->r18;
@ -89,7 +78,16 @@ _hurd_setup_sighandler (int flags,
scp->sc_fp = ts->r30; scp->sc_fp = ts->r30;
/* Modify the thread state to call `trampoline' on the new stack. */ /* Modify the thread state to call `trampoline' on the new stack. */
ts->r29 = (int) sigsp;
/* These registers are used for passing the first four arguments to a
function (the rest go on the stack). Fortunately `trampoline' takes
just four arguments, so they all fit in registers. */
ts->r4 = (int) handler;
ts->r5 = signo;
ts->r6 = sigcode;
ts->r7 = (int) scp;
ts->r29 = (int) sigsp; /* r29 is the stack pointer register. */
ts->pc = (int) &trampoline; ts->pc = (int) &trampoline;
return scp; return scp;