ACPR/android_system_core
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Merge "x86_64: mmap rnd bits: Allow min bits of less than 32" into main

Browse source
This commit is contained in:
Kalesh Singh 2023-11-17 21:23:26 +00:00 • committed by Gerrit Code Review
commit 72d8882153
1 changed files with 7 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

9
init/security.cpp
View file

@ -20,6 +20,7 @@
#include <errno.h>
#include <fcntl.h>
#include <linux/perf_event.h>
#include <math.h>
#include <selinux/selinux.h>
#include <sys/ioctl.h>
#include <sys/syscall.h>
@ -121,8 +122,12 @@ Result<void> SetMmapRndBitsAction(const BuiltinArguments&) {
}
#elif defined(__x86_64__)
// x86_64 supports 28 - 32 rnd bits, but Android wants to ensure that the
// theoretical maximum of 32 bits is always supported and used.
if (SetMmapRndBitsMin(32, 32, false) && (!Has32BitAbi() || SetMmapRndBitsMin(16, 16, true))) {
// theoretical maximum of 32 bits is always supported and used; except in
// the case of the x86 page size emulator which supports a maximum
// of 30 bits for 16k page size, or 28 bits for 64k page size.
int max_bits = 32 - (static_cast<int>(log2(getpagesize())) - 12);
if (SetMmapRndBitsMin(max_bits, max_bits, false) &&
(!Has32BitAbi() || SetMmapRndBitsMin(16, 16, true))) {
return {};
}
#elif defined(__arm__) || defined(__i386__)