diff options
| -rw-r--r-- | sys/alpha/alpha/trap.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/sys/alpha/alpha/trap.c b/sys/alpha/alpha/trap.c index ab75b4b..fc04abc 100644 --- a/sys/alpha/alpha/trap.c +++ b/sys/alpha/alpha/trap.c @@ -39,6 +39,7 @@ #include <sys/signalvar.h> #include <sys/kernel.h> #include <sys/proc.h> +#include <sys/exec.h> #include <sys/lock.h> #include <sys/vmmeter.h> #include <sys/buf.h> @@ -387,11 +388,27 @@ trap(a0, a1, a2, entry, framep) * 3. pcb_onfault set but kernel space data fault * The last can occur during an exec() copyin where the * argument space is lazy-allocated. + * + * For the purposes of the Linux emulator, we allow + * kernel accesses to a small region of the + * user stack which the emulator uses to + * translate syscall arguments. */ - if (!user && (a0 >= VM_MIN_KERNEL_ADDRESS || - p == NULL || p->p_addr->u_pcb.pcb_onfault == 0)) - map = kernel_map; - else { + if (!user + && ((a0 >= VM_MIN_KERNEL_ADDRESS) + || (p == NULL) + || (p->p_addr->u_pcb.pcb_onfault == 0))) { + if (a0 >= trunc_page(PS_STRINGS + - szsigcode + - SPARE_USRSPACE) + && a0 < round_page(PS_STRINGS + - szsigcode)) { + vm = p->p_vmspace; + map = &vm->vm_map; + } else { + map = kernel_map; + } + } else { vm = p->p_vmspace; map = &vm->vm_map; } |
