ref: 3ddb2e652a782498d7e567645ff50a8fc56177a4
parent: 853f92087bd12f37771f326d31a8ccdfdc77096b
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Thu Mar 28 17:52:38 EDT 2024
kernel: zero up->ureg on sysexec() and pexit() The up->ureg pointer points to the last delivered note in the user-space stack. On exec(), all the notes are cleared and the ureg pointer should be zeroed as well as it points into the previous programs stack. Note, this can only happen if someone does exec() from a note handler. When we pexit(), also zero the up->ureg and up->dbgreg as we are about to release the memory segments and nobody should debugging user-space anymore.
--- a/sys/src/9/port/proc.c
+++ b/sys/src/9/port/proc.c
@@ -1348,6 +1348,8 @@
freenote(up->lastnote);
up->lastnote = nil;
up->notified = 0;
+ up->ureg = nil;
+ up->dbgreg = nil;
/* release debuggers */
if(up->pdbg != nil) {--- a/sys/src/9/port/sysproc.c
+++ b/sys/src/9/port/sysproc.c
@@ -607,6 +607,7 @@
up->lastnote = nil;
up->notify = nil;
up->notified = 0;
+ up->ureg = nil;
up->privatemem = 0;
up->noswap = 0;
up->pcycles = -up->kentry;
--
⑨