Date: Fri, 18 Jul 2014 16:08:27 GMT From: op@FreeBSD.org To: svn-soc-all@FreeBSD.org Subject: socsvn commit: r271085 - in soc2014/op/freebsd-base/sys: kern sys Message-ID: <201407181608.s6IG8RXh052608@socsvn.freebsd.org>
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Author: op Date: Fri Jul 18 16:08:27 2014 New Revision: 271085 URL: http://svnweb.FreeBSD.org/socsvn/?view=rev&rev=271085 Log: KSP: change destination memory region from RX to RWX, and after patching back to RX Signed-off-by: Oliver Pinter <oliver.pntr@gmail.com> git: https://github.com/opntr/opBSD/tree/op/gsoc2014/kpatch Modified: soc2014/op/freebsd-base/sys/kern/kern_selfpatch.c soc2014/op/freebsd-base/sys/sys/selfpatch.h Modified: soc2014/op/freebsd-base/sys/kern/kern_selfpatch.c ============================================================================== --- soc2014/op/freebsd-base/sys/kern/kern_selfpatch.c Fri Jul 18 16:07:58 2014 (r271084) +++ soc2014/op/freebsd-base/sys/kern/kern_selfpatch.c Fri Jul 18 16:08:27 2014 (r271085) @@ -34,12 +34,16 @@ #include <sys/systm.h> #include <sys/types.h> #include <sys/kernel.h> +#include <sys/malloc.h> #include <sys/linker.h> #include <sys/linker_set.h> #include <sys/selfpatch.h> #include <sys/sysctl.h> +#include <vm/vm.h> +#include <vm/pmap.h> + #include <machine/md_var.h> #include <machine/specialreg.h> @@ -135,13 +139,49 @@ void lf_selfpatch_apply(linker_file_t lf, struct lf_selfpatch *p) { + vm_paddr_t *pages; + vm_offset_t page_offset; + int i, page_number; + if (!lf_selfpatch_patch_needed(p)) return; KASSERT(p->patch_size == p->patchable_size, ("%s: patch_size != patchable_size", __func__)); - DBG("%p\n", p->patch); + page_offset = (vm_offset_t)p->patchable & (vm_offset_t)PAGE_MASK; + page_number = (p->patchable_size >> PAGE_SHIFT) + + ((page_offset + p->patchable_size) > PAGE_SIZE ? 2 : 1); + + pages = malloc(page_number, M_TEMP, M_WAITOK | M_ZERO); + + DBG("change mapping attribute from RX to RWX\n"); + for (i=0; i<page_number; i++) { + vm_paddr_t kva; + + kva = trunc_page(p->patchable) + i * PAGE_SIZE; + pages[i] = pmap_kextract(kva); + pmap_kenter_attr(kva, pages[i], VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE); + } + DBG("done.\n"); + + DBG("patchable: %p\n", p->patchable); + DBG("patch: %p\n", p->patch); + DBG("patch size: %d\n", p->patchable_size); memcpy(p->patchable, p->patch, p->patchable_size); + + DBG("patched.\n"); + + DBG("change mapping attribute from RWX to RX:\n"); + for (i=0; i<page_number; i++) { + vm_paddr_t kva; + + kva = trunc_page(p->patchable) + i * PAGE_SIZE; + pmap_kenter_attr(kva, pages[i], VM_PROT_READ | VM_PROT_EXECUTE); + } + DBG("done.\n"); + + free(pages, M_TEMP); } + Modified: soc2014/op/freebsd-base/sys/sys/selfpatch.h ============================================================================== --- soc2014/op/freebsd-base/sys/sys/selfpatch.h Fri Jul 18 16:07:58 2014 (r271084) +++ soc2014/op/freebsd-base/sys/sys/selfpatch.h Fri Jul 18 16:08:27 2014 (r271085) @@ -34,8 +34,8 @@ struct linker_file_t; typedef struct lf_selfpatch { - void *patchable; - void *patch; + char *patchable; + char *patch; int patchable_size; int patch_size; int feature_selector;
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