From 3c6b5bfa3cf3b4057788e08482a468cc3bc00780 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 22 Oct 2007 11:03:26 +1000 Subject: Introduce guest mem offset, static link example launcher In order to avoid problematic special linking of the Launcher, we give the Host an offset: this means we can use any memory region in the Launcher as Guest memory rather than insisting on mmap() at 0. The result is quite pleasing: a number of casts are replaced with simple additions. Signed-off-by: Rusty Russell --- drivers/lguest/io.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) (limited to 'drivers/lguest/io.c') diff --git a/drivers/lguest/io.c b/drivers/lguest/io.c index ea68613b43f..3a845335fee 100644 --- a/drivers/lguest/io.c +++ b/drivers/lguest/io.c @@ -186,7 +186,7 @@ int bind_dma(struct lguest *lg, * we're doing this. */ mutex_lock(&lguest_lock); down_read(fshared); - if (get_futex_key((u32 __user *)ukey, fshared, &key) != 0) { + if (get_futex_key(lg->mem_base + ukey, fshared, &key) != 0) { kill_guest(lg, "bad dma key %#lx", ukey); goto unlock; } @@ -247,7 +247,8 @@ static int lgread_other(struct lguest *lg, void *buf, u32 addr, unsigned bytes) { if (!lguest_address_ok(lg, addr, bytes) - || access_process_vm(lg->tsk, addr, buf, bytes, 0) != bytes) { + || access_process_vm(lg->tsk, (unsigned long)lg->mem_base + addr, + buf, bytes, 0) != bytes) { memset(buf, 0, bytes); kill_guest(lg, "bad address in registered DMA struct"); return 0; @@ -261,8 +262,8 @@ static int lgwrite_other(struct lguest *lg, u32 addr, const void *buf, unsigned bytes) { if (!lguest_address_ok(lg, addr, bytes) - || (access_process_vm(lg->tsk, addr, (void *)buf, bytes, 1) - != bytes)) { + || access_process_vm(lg->tsk, (unsigned long)lg->mem_base + addr, + (void *)buf, bytes, 1) != bytes) { kill_guest(lg, "bad address writing to registered DMA"); return 0; } @@ -318,7 +319,7 @@ static u32 copy_data(struct lguest *srclg, * copy_to_user_page(), and some arch's seem to need special * flushes. x86 is fine. */ if (copy_from_user(maddr + (dst->addr[di] + dstoff)%PAGE_SIZE, - (void __user *)src->addr[si], len) != 0) { + srclg->mem_base+src->addr[si], len) != 0) { /* If a copy failed, it's the source's fault. */ kill_guest(srclg, "bad address in sending DMA"); totlen = 0; @@ -377,7 +378,8 @@ static u32 do_dma(struct lguest *srclg, const struct lguest_dma *src, * number of pages. Note that we're holding the destination's * mmap_sem, as get_user_pages() requires. */ if (get_user_pages(dstlg->tsk, dstlg->mm, - dst->addr[i], 1, 1, 1, pages+i, NULL) + (unsigned long)dstlg->mem_base+dst->addr[i], + 1, 1, 1, pages+i, NULL) != 1) { /* This means the destination gave us a bogus buffer */ kill_guest(dstlg, "Error mapping DMA pages"); @@ -493,7 +495,7 @@ again: mutex_lock(&lguest_lock); down_read(fshared); /* Get the futex key for the key the Guest gave us */ - if (get_futex_key((u32 __user *)ukey, fshared, &key) != 0) { + if (get_futex_key(lg->mem_base + ukey, fshared, &key) != 0) { kill_guest(lg, "bad sending DMA key"); goto unlock; } @@ -584,7 +586,7 @@ unsigned long get_dma_buffer(struct lguest *lg, /* This can fail if it's not a valid address, or if the address is not * divisible by 4 (the futex code needs that, we don't really). */ - if (get_futex_key((u32 __user *)ukey, fshared, &key) != 0) { + if (get_futex_key(lg->mem_base + ukey, fshared, &key) != 0) { kill_guest(lg, "bad registered DMA buffer"); goto unlock; } -- cgit v1.2.2