From 58e80f030f6af0b5a902eeb19fa61e21bf70abbd Mon Sep 17 00:00:00 2001 From: bjh21 Date: Wed, 27 Dec 2000 16:57:09 +0000 Subject: [PATCH] Two batches of changes: 1: Cleanup of syscall() -- treat the arguments as an array of register_t throughout. This saves a few casts, and generally makes seeing what's going on easier. 2: Be a little more careful in the handling of data aborts on kernel addresses: don't use the kernel's map unless the access was actually from a kernel mode. This is how the arm32 data abort handler behaves. --- sys/arch/arm26/arm26/except.c | 67 ++++++++++++++++++++++------------- 1 file changed, 43 insertions(+), 24 deletions(-) diff --git a/sys/arch/arm26/arm26/except.c b/sys/arch/arm26/arm26/except.c index 77cc25e3b983..a19cfb98e1a6 100644 --- a/sys/arch/arm26/arm26/except.c +++ b/sys/arch/arm26/arm26/except.c @@ -1,4 +1,4 @@ -/* $NetBSD: except.c,v 1.20 2000/12/23 15:12:54 bjh21 Exp $ */ +/* $NetBSD: except.c,v 1.21 2000/12/27 16:57:09 bjh21 Exp $ */ /*- * Copyright (c) 1998, 1999, 2000 Ben Harris * All rights reserved. @@ -32,7 +32,7 @@ #include -__KERNEL_RCSID(0, "$NetBSD: except.c,v 1.20 2000/12/23 15:12:54 bjh21 Exp $"); +__KERNEL_RCSID(0, "$NetBSD: except.c,v 1.21 2000/12/27 16:57:09 bjh21 Exp $"); #include "opt_cputypes.h" #include "opt_ddb.h" @@ -68,6 +68,7 @@ void syscall(struct trapframe *); static void data_abort_fixup(struct trapframe *); static vaddr_t data_abort_address(struct trapframe *); static vm_prot_t data_abort_atype(struct trapframe *); +static boolean_t data_abort_usrmode(struct trapframe *); #ifdef DEBUG static void printregs(struct trapframe *tf); #endif @@ -195,10 +196,9 @@ syscall(struct trapframe *tf) u_quad_t sticks; struct proc *p; vaddr_t pc; - int code, regparams, nextreg; + int code, nargs, nregargs, nextreg, nstkargs; const struct sysent *sy; - size_t argsize, regargsize, stkargsize; - char args[32]; /* XXX just enough for mmap... */ + register_t args[8]; /* XXX just enough for mmap... */ register_t rval[2], or15; int error; @@ -238,38 +238,34 @@ syscall(struct trapframe *tf) switch (code) { case SYS_syscall: /* Indirect system call. First arg is new code */ code = tf->tf_r0; - regparams = 3; nextreg = 1; + nregargs = 3; nextreg = 1; break; case SYS___syscall: /* As above, but quad_t arg */ if (p->p_emul->e_sysent == sysent) { /* NetBSD emulation */ code = tf->tf_r0; /* XXX assume little-endian */ - regparams = 2; nextreg = 2; + nregargs = 2; nextreg = 2; break; } /* FALLTHROUGH */ default: - regparams = 4; nextreg = 0; + nregargs = 4; nextreg = 0; } if (code > p->p_emul->e_nsysent) sy = p->p_emul->e_sysent + p->p_emul->e_nosys; else sy = p->p_emul->e_sysent + code; - argsize = sy->sy_argsize; - if (argsize > (regparams * sizeof(int))) { - regargsize = regparams*sizeof(int); - stkargsize = argsize - regargsize; - } else { - regargsize = argsize; - stkargsize = 0; - } + nargs = sy->sy_argsize / sizeof(register_t); + nregargs = min(nregargs, nargs); + nstkargs = nargs - nregargs; - if (regargsize) - bcopy((char *)tf + nextreg * sizeof(int), args, regargsize); + if (nregargs > 0) + bcopy((register_t *)tf + nextreg, args, + nregargs * sizeof(register_t)); - if (stkargsize) { - error = copyin((caddr_t)tf->tf_r13, args + regargsize, - stkargsize); + if (nstkargs > 0) { + error = copyin((caddr_t)tf->tf_r13, args + nregargs, + nstkargs * sizeof(register_t)); if (error) { #ifdef SYSCALL_DEBUG scdebug_call(p, code, (register_t *)args); @@ -279,11 +275,11 @@ syscall(struct trapframe *tf) } #ifdef SYSCALL_DEBUG - scdebug_call(p, code, (register_t *)args); + scdebug_call(p, code, args); #endif #ifdef KTRACE if (KTRPOINT(p, KTR_SYSCALL)) - ktrsyscall(p, code, argsize, (register_t *)args); + ktrsyscall(p, code, nargs * sizeof(register_t), args); #endif rval[0] = 0; @@ -360,6 +356,7 @@ prefetch_abort_handler(struct trapframe *tf) int_on(); /* + * XXX Not done yet: * Check if the page being requested is already present. If * so, call the undefined instruction handler instead (ARM3 ds * p15). @@ -418,6 +415,7 @@ data_abort_handler(struct trapframe *tf) int ret; struct proc *p; vm_prot_t atype; + boolean_t usrmode; vm_map_t map; struct pcb *curpcb; @@ -446,7 +444,11 @@ data_abort_handler(struct trapframe *tf) data_abort_fixup(tf); va = data_abort_address(tf); atype = data_abort_atype(tf); - map = va >= VM_MIN_KERNEL_ADDRESS ? kernel_map : &p->p_vmspace->vm_map; + usrmode = data_abort_usrmode(tf); + if (!usrmode && va >= VM_MIN_KERNEL_ADDRESS) + map = kernel_map; + else + map = &p->p_vmspace->vm_map; if (pmap_fault(map->pmap, va, atype)) goto out; for (;;) { @@ -661,6 +663,23 @@ data_abort_atype(struct trapframe *tf) #endif return VM_PROT_READ; } + +/* + * Work out what effective mode was in use when a data abort occurred. + */ +static boolean_t +data_abort_usrmode(struct trapframe *tf) +{ + register_t insn; + + if ((tf->tf_r15 & R15_MODE) == R15_MODE_USR) + return TRUE; + insn = *(register_t *)(tf->tf_r15 & R15_PC); + if ((insn & 0x0d200000) == 0x04200000) + /* LDR[B]T and STR[B]T */ + return TRUE; + return FALSE; +} void address_exception_handler(struct trapframe *tf)