From: deraadt <deraadt@openbsd.org>
Date: Mon, 14 Nov 2022 13:12:59 +0000 (+0000)
Subject: Since the introduction of automatic immutable from the kernel, the munmap()
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=e201c79b92ba0b20b8a77f040ae649ec8fe0b8b5;p=openbsd

Since the introduction of automatic immutable from the kernel, the munmap()
of ld.so boot.text region is now (silently) failing because the region is
contained within the text LOAD, which is immutable.  So create a new btext
LOAD with flags PF_X|PF_R|PF_OPENBSD_MUTABLE, and place all boot.text objects
in there.  This LOAD must also be page-aligned so it doesn't skip unmapping
some of the object region, previously it was hilariously unaligned.
ok kettenis and guenther seemed to like it also
This one is for powerpc64 and a modified version of the diff deraadt@ mailed
out to make sure the LOADs are in increasing address order.
this is the version for powerpc, tested by pascal
---

diff --git a/libexec/ld.so/powerpc/ld.script b/libexec/ld.so/powerpc/ld.script
index 96614bc9732..b3cd710479c 100644
--- a/libexec/ld.so/powerpc/ld.script
+++ b/libexec/ld.so/powerpc/ld.script
@@ -2,6 +2,7 @@ PHDRS
 {
 	rodata	PT_LOAD FILEHDR PHDRS FLAGS (4);
 	text	PT_LOAD;
+	btext	PT_LOAD FLAGS (0x08000005);
 	data	PT_LOAD;
 	random	PT_OPENBSD_RANDOMIZE;
 	relro	PT_GNU_RELRO;
@@ -23,10 +24,12 @@ SECTIONS
     . = ALIGN(0x10000);
     .boot.text	:
     {
+	. = ALIGN(0x1000);
 	boot_text_start = .;
 	*(.boot.text)
+	. = ALIGN(0x1000);
 	boot_text_end = .;
-    } :text
+    } :btext
     . = ALIGN(0x1000);
     .text	: { *(.text .text.*) } :text