diff options
| author | bde <bde@FreeBSD.org> | 1997-11-20 18:09:36 +0000 |
|---|---|---|
| committer | bde <bde@FreeBSD.org> | 1997-11-20 18:09:36 +0000 |
| commit | dfbf1ec5a96e49d821416565e5196af4a3be0882 (patch) | |
| tree | edf0fecf43dc743e48e4835f8ebd2e8c50a25ccc /sys | |
| parent | dbdea37b8422a75dd03baeb05d688bb75fceff8e (diff) | |
| download | FreeBSD-src-dfbf1ec5a96e49d821416565e5196af4a3be0882.zip FreeBSD-src-dfbf1ec5a96e49d821416565e5196af4a3be0882.tar.gz | |
Fixed write enabling of the kernel text section. The overlap
checking was mostly wrong at the boundaries. For the lower limit,
VM_MIN_KERNEL_ADDRESS was used instead of btext and there was an
off-by-(`size' - 1) error. For the upper limit, &etext was used
instead of etext and there was an off-by-1 error. The bugs were
harmless because `size' is not too large and some memory is mapped
just beyond the ends. We still depend on the former to avoid
having to handle the case where the memory range covers the whole
text section, and on the latter to prevent problems when we map
just beyond an end to allow writing an address range that overlaps
the end.
Fixed placement of a nearby comment.
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/amd64/amd64/db_interface.c | 12 | ||||
| -rw-r--r-- | sys/i386/i386/db_interface.c | 12 |
2 files changed, 10 insertions, 14 deletions
diff --git a/sys/amd64/amd64/db_interface.c b/sys/amd64/amd64/db_interface.c index b05285a..513c97e 100644 --- a/sys/amd64/amd64/db_interface.c +++ b/sys/amd64/amd64/db_interface.c @@ -23,7 +23,7 @@ * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. * - * $Id: db_interface.c,v 1.36 1997/08/07 05:15:46 dyson Exp $ + * $Id: db_interface.c,v 1.37 1997/10/27 17:23:12 bde Exp $ */ /* @@ -41,7 +41,6 @@ #endif #include <vm/vm.h> -#include <vm/vm_param.h> #include <vm/pmap.h> #include <ddb/ddb.h> @@ -247,17 +246,16 @@ db_write_bytes(addr, size, data) db_nofault = &db_jmpbuf; - if (addr >= VM_MIN_KERNEL_ADDRESS && - addr <= round_page((vm_offset_t)&etext)) { + if (addr > trunc_page((vm_offset_t)btext) - size && + addr < round_page((vm_offset_t)etext)) { ptep0 = pmap_pte(kernel_pmap, addr); oldmap0 = *ptep0; *ptep0 |= PG_RW; - if ((*ptep0 & PG_PS) == 0) { + /* Map another page if the data crosses a page boundary. */ + if ((*ptep0 & PG_PS) == 0) { addr1 = trunc_page(addr + size - 1); - - /* Map another page if the data crosses a page boundary. */ if (trunc_page(addr) != addr1) { ptep1 = pmap_pte(kernel_pmap, addr1); oldmap1 = *ptep1; diff --git a/sys/i386/i386/db_interface.c b/sys/i386/i386/db_interface.c index b05285a..513c97e 100644 --- a/sys/i386/i386/db_interface.c +++ b/sys/i386/i386/db_interface.c @@ -23,7 +23,7 @@ * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. * - * $Id: db_interface.c,v 1.36 1997/08/07 05:15:46 dyson Exp $ + * $Id: db_interface.c,v 1.37 1997/10/27 17:23:12 bde Exp $ */ /* @@ -41,7 +41,6 @@ #endif #include <vm/vm.h> -#include <vm/vm_param.h> #include <vm/pmap.h> #include <ddb/ddb.h> @@ -247,17 +246,16 @@ db_write_bytes(addr, size, data) db_nofault = &db_jmpbuf; - if (addr >= VM_MIN_KERNEL_ADDRESS && - addr <= round_page((vm_offset_t)&etext)) { + if (addr > trunc_page((vm_offset_t)btext) - size && + addr < round_page((vm_offset_t)etext)) { ptep0 = pmap_pte(kernel_pmap, addr); oldmap0 = *ptep0; *ptep0 |= PG_RW; - if ((*ptep0 & PG_PS) == 0) { + /* Map another page if the data crosses a page boundary. */ + if ((*ptep0 & PG_PS) == 0) { addr1 = trunc_page(addr + size - 1); - - /* Map another page if the data crosses a page boundary. */ if (trunc_page(addr) != addr1) { ptep1 = pmap_pte(kernel_pmap, addr1); oldmap1 = *ptep1; |
