diff options
| author | Hari Bathini <[email protected]> | 2024-07-01 18:30:21 +0530 |
|---|---|---|
| committer | Michael Ellerman <[email protected]> | 2024-07-04 21:55:18 +1000 |
| commit | 353d7a84c214f184d5a6b62acdec8b4424159b7c (patch) | |
| tree | fb937a06009b256f5ed52cc04355ede08b870a5e /arch/powerpc/mm/init-common.c | |
| parent | af199e6ca29c77fb8fea9a78f18dfb165af37cd7 (diff) | |
powerpc/64s/radix/kfence: map __kfence_pool at page granularity
When KFENCE is enabled, total system memory is mapped at page level
granularity. But in radix MMU mode, ~3GB additional memory is needed
to map 100GB of system memory at page level granularity when compared
to using 2MB direct mapping.This is not desired considering KFENCE is
designed to be enabled in production kernels [1].
Mapping only the memory allocated for KFENCE pool at page granularity is
sufficient to enable KFENCE support. So, allocate __kfence_pool during
bootup and map it at page granularity instead of mapping all system
memory at page granularity.
Without patch:
# cat /proc/meminfo
MemTotal: 101201920 kB
With patch:
# cat /proc/meminfo
MemTotal: 104483904 kB
Note that enabling KFENCE at runtime is disabled for radix MMU for now,
as it depends on the ability to split page table mappings and such APIs
are not currently implemented for radix MMU.
All kfence_test.c testcases passed with this patch.
[1] https://lore.kernel.org/all/[email protected]/
Signed-off-by: Hari Bathini <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]
Diffstat (limited to 'arch/powerpc/mm/init-common.c')
| -rw-r--r-- | arch/powerpc/mm/init-common.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c index d3a7726ecf51..21131b96d209 100644 --- a/arch/powerpc/mm/init-common.c +++ b/arch/powerpc/mm/init-common.c @@ -31,6 +31,9 @@ EXPORT_SYMBOL_GPL(kernstart_virt_addr); bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP); bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP); +#ifdef CONFIG_KFENCE +bool __ro_after_init kfence_disabled; +#endif static int __init parse_nosmep(char *p) { |