Module Name: src
Committed By: martin
Date: Tue Jan 7 11:59:49 UTC 2020
Modified Files:
src/sys/kern [netbsd-8]: kern_ksyms.c
Log Message:
Pull up following revision(s) (requested by pgoyette in ticket #1482):
sys/kern/kern_ksyms.c: revision 1.88 (patch)
When reading from /dev/ksyms we need to skip over entries that have
been marked as sd_gone. Otherwise we might try to uiomove() data from
memory that has been unmapped, resulting in EFAULT.
XXX This (along with other pre-existing checks st->sd_gone) is still
racy, but it's an improvement over current code. Ideally we would
make a complete copy of the symbol table when we open /dev/ksyms so
we could ignore any changes that occur.
ad@ says "good enough for now"
XXX Pullup to -9 and -8
To generate a diff of this commit:
cvs rdiff -u -r1.84 -r1.84.10.1 src/sys/kern/kern_ksyms.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/kern_ksyms.c
diff -u src/sys/kern/kern_ksyms.c:1.84 src/sys/kern/kern_ksyms.c:1.84.10.1
--- src/sys/kern/kern_ksyms.c:1.84 Thu Jul 7 06:55:43 2016
+++ src/sys/kern/kern_ksyms.c Tue Jan 7 11:59:48 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_ksyms.c,v 1.84 2016/07/07 06:55:43 msaitoh Exp $ */
+/* $NetBSD: kern_ksyms.c,v 1.84.10.1 2020/01/07 11:59:48 martin Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -73,7 +73,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_ksyms.c,v 1.84 2016/07/07 06:55:43 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_ksyms.c,v 1.84.10.1 2020/01/07 11:59:48 martin Exp $");
#if defined(_KERNEL) && defined(_KERNEL_OPT)
#include "opt_copy_symtab.h"
@@ -754,9 +754,9 @@ ksyms_modunload(const char *name)
if (strcmp(name, st->sd_name) != 0)
continue;
st->sd_gone = true;
+ ksyms_sizes_calc();
if (!ksyms_isopen) {
TAILQ_REMOVE(&ksyms_symtabs, st, sd_queue);
- ksyms_sizes_calc();
kmem_free(st, sizeof(*st));
}
break;
@@ -843,6 +843,8 @@ ksyms_sizes_calc(void)
ksyms_symsz = ksyms_strsz = 0;
TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) {
+ if (__predict_false(st->sd_gone))
+ continue;
delta = ksyms_strsz - st->sd_usroffset;
if (delta != 0) {
for (i = 0; i < st->sd_symsize/sizeof(Elf_Sym); i++)
@@ -1019,6 +1021,8 @@ ksymsread(dev_t dev, struct uio *uio, in
*/
filepos = sizeof(struct ksyms_hdr);
TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) {
+ if (__predict_false(st->sd_gone))
+ continue;
if (uio->uio_resid == 0)
return 0;
if (uio->uio_offset <= st->sd_symsize + filepos) {
@@ -1037,6 +1041,8 @@ ksymsread(dev_t dev, struct uio *uio, in
KASSERT(filepos == sizeof(struct ksyms_hdr) +
ksyms_hdr.kh_shdr[SYMTAB].sh_size);
TAILQ_FOREACH(st, &ksyms_symtabs, sd_queue) {
+ if (__predict_false(st->sd_gone))
+ continue;
if (uio->uio_resid == 0)
return 0;
if (uio->uio_offset <= st->sd_strsize + filepos) {
