Author: bdragon
Date: Thu Aug 6 17:49:19 2020
New Revision: 363972
URL: https://svnweb.freebsd.org/changeset/base/363972
Log:
[POWERPC] Fix ppc64 makecontext() parameter overflow handling.
On ELFv2, the overflow parameters in the stack frame are at a different offset
from sp than ELFv1. Adjust code to use the correct offset in all cases.
This had resulted in argv[8] and up being copied to the incorrect address
in the new context's initial stack frame.
This is not necessarily the only bug in this function, I need to do a full
review still and ensure the rest of the math is sane for ELFv2 stack frames.
Reported by: pherde (Probably. My notes are a bit unclear.)
Reviewed by: jhibbits (in irc)
Sponsored by: Tag1 Consulting, Inc.
Modified:
head/lib/libc/powerpc64/gen/makecontext.c
Modified: head/lib/libc/powerpc64/gen/makecontext.c
==============================================================================
--- head/lib/libc/powerpc64/gen/makecontext.c Thu Aug 6 16:44:24 2020
(r363971)
+++ head/lib/libc/powerpc64/gen/makecontext.c Thu Aug 6 17:49:19 2020
(r363972)
@@ -102,7 +102,11 @@ __makecontext(ucontext_t *ucp, void (*start)(void), in
uint64_t *argp;
/* Skip past frame pointer and saved LR */
+#if !defined(_CALL_ELF) || _CALL_ELF == 1
argp = (uint64_t *)sp + 6;
+#else
+ argp = (uint64_t *)sp + 4;
+#endif
for (i = 0; i < stackargs; i++)
*argp++ = va_arg(ap, uint64_t);
_______________________________________________
svn-src-head@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
