> Date: Thu, 13 Jul 2017 14:54:41 +0200
> From: Alexander Bluhm <alexander.bl...@gmx.net>
>
> Hi,
>
> The regress test src/regress/sys/kern/siginfo-fault checks wether
> the si_code is set to SEGV_ACCERR after memory access with wrong
> permissions has triggert a SIGSEGV.
>
> Relevant commit message of the test is:
> According to POSIX, SIGSEGV should specify SEGV_ACCERR if the memory
> pages are mapped, but the protections don't match the user's access
> attempts, while SEGV_MAPERR should only be specified for pages that
> are unmapped. Some platforms currently handle this correctly, but not
> all.
>
> This diff changes the behavior of i366 and amd64. hppa seems to
> do something similar. Changing error form EACCES to EFAULT in amd64
> affects only a printf, so I removed the useless code. Also change
> rv to errno in i386 to make it look like amd64.
>
> ok?
I like this. ok kettenis@
> Index: arch/amd64/amd64/trap.c
> ===================================================================
> RCS file: /data/mirror/openbsd/cvs/src/sys/arch/amd64/amd64/trap.c,v
> retrieving revision 1.54
> diff -u -p -r1.54 trap.c
> --- arch/amd64/amd64/trap.c 30 Apr 2017 13:04:49 -0000 1.54
> +++ arch/amd64/amd64/trap.c 13 Jul 2017 12:31:28 -0000
> @@ -362,9 +362,6 @@ faultcommon:
> KERNEL_UNLOCK();
> goto out;
> }
> - if (error == EACCES) {
> - error = EFAULT;
> - }
>
> if (type == T_PAGEFLT) {
> if (pcb->pcb_onfault != 0) {
> @@ -389,7 +386,8 @@ faultcommon:
> frame_dump(frame);
> #endif
> sv.sival_ptr = (void *)fa;
> - trapsignal(p, SIGSEGV, T_PAGEFLT, SEGV_MAPERR, sv);
> + trapsignal(p, SIGSEGV, T_PAGEFLT,
> + error == EACCES ? SEGV_ACCERR : SEGV_MAPERR, sv);
> }
> KERNEL_UNLOCK();
> break;
> Index: arch/i386/i386/trap.c
> ===================================================================
> RCS file: /data/mirror/openbsd/cvs/src/sys/arch/i386/i386/trap.c,v
> retrieving revision 1.130
> diff -u -p -r1.130 trap.c
> --- arch/i386/i386/trap.c 30 Apr 2017 13:04:49 -0000 1.130
> +++ arch/i386/i386/trap.c 13 Jul 2017 12:33:30 -0000
> @@ -373,7 +373,7 @@ trap(struct trapframe *frame)
> vaddr_t va, fa;
> struct vmspace *vm;
> struct vm_map *map;
> - int rv;
> + int error;
>
> cr2 = rcr2();
> KERNEL_LOCK();
> @@ -406,12 +406,12 @@ trap(struct trapframe *frame)
> if (curcpu()->ci_inatomic == 0 || map == kernel_map) {
> onfault = p->p_addr->u_pcb.pcb_onfault;
> p->p_addr->u_pcb.pcb_onfault = NULL;
> - rv = uvm_fault(map, va, 0, ftype);
> + error = uvm_fault(map, va, 0, ftype);
> p->p_addr->u_pcb.pcb_onfault = onfault;
> } else
> - rv = EFAULT;
> + error = EFAULT;
>
> - if (rv == 0) {
> + if (error == 0) {
> if (map != kernel_map)
> uvm_grow(p, va);
> if (type == T_PAGEFLT) {
> @@ -428,11 +428,12 @@ trap(struct trapframe *frame)
> goto copyfault;
> }
> printf("uvm_fault(%p, 0x%lx, 0, %d) -> %x\n",
> - map, va, ftype, rv);
> + map, va, ftype, error);
> goto we_re_toast;
> }
> sv.sival_int = fa;
> - trapsignal(p, SIGSEGV, vftype, SEGV_MAPERR, sv);
> + trapsignal(p, SIGSEGV, vftype,
> + error == EACCES ? SEGV_ACCERR : SEGV_MAPERR, sv);
> KERNEL_UNLOCK();
> break;
> }
>
>
