linux

iv/linux

History

Heiko Carstens 33bd8d153c s390: Keep inittext section writable

There is no added security by making the inittext section non-writable,
however it does split part of the kernel mapping into 4K mappings
instead of 1M mappings:

---[ Kernel Image Start ]---
0x000003ffe0000000-0x000003ffe0e00000        14M PMD RO X
0x000003ffe0e00000-0x000003ffe0ec7000       796K PTE RO X
0x000003ffe0ec7000-0x000003ffe0f00000       228K PTE RO NX
0x000003ffe0f00000-0x000003ffe1300000         4M PMD RO NX
0x000003ffe1300000-0x000003ffe1353000       332K PTE RO NX
0x000003ffe1353000-0x000003ffe1400000       692K PTE RW NX
0x000003ffe1400000-0x000003ffe1500000         1M PMD RW NX
0x000003ffe1500000-0x000003ffe1700000         2M PTE RW NX <---
0x000003ffe1700000-0x000003ffe1800000         1M PMD RW NX
0x000003ffe1800000-0x000003ffe187e000       504K PTE RW NX
---[ Kernel Image End ]---

Keep the inittext writable and enable instruction execution protection
(aka noexec) later to prevent this. This also allows to use the
generic free_initmem() implementation.

---[ Kernel Image Start ]---
0x000003ffe0000000-0x000003ffe0e00000        14M PMD RO X
0x000003ffe0e00000-0x000003ffe0ec7000       796K PTE RO X
0x000003ffe0ec7000-0x000003ffe0f00000       228K PTE RO NX
0x000003ffe0f00000-0x000003ffe1300000         4M PMD RO NX
0x000003ffe1300000-0x000003ffe1353000       332K PTE RO NX
0x000003ffe1353000-0x000003ffe1400000       692K PTE RW NX
0x000003ffe1400000-0x000003ffe1800000         4M PMD RW NX <---
0x000003ffe1800000-0x000003ffe187e000       504K PTE RW NX
---[ Kernel Image End ]---

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

2024-07-31 16:30:20 +02:00

appldata

sysctl: treewide: constify the ctl_table argument of proc_handlers

2024-07-24 20:59:29 +02:00

boot

more s390 updates for 6.11 merge window

2024-07-26 10:47:53 -07:00

configs

s390: Remove protvirt and kvm config guards for uv code

2024-07-23 16:02:33 +02:00

crypto

s390/crc32: Add missing MODULE_DESCRIPTION() macro