diff options
| author |   Christophe Leroy <christophe.leroy@csgroup.eu> | 2022-01-17 10:06:39 +0000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2022-02-12 22:47:42 +1100 |
| commit | 0670010f3b10aeaad0dfdf0dad0bcd020fc70eb5 (patch) | |
| tree | ef1260794144f7f69fbbb0a12e4740fc32ae727b | |
| parent | powerpc/bpf: Always reallocate BPF_REG_5, BPF_REG_AX and TMP_REG when possible (diff) | |
| download | linux-dev-0670010f3b10aeaad0dfdf0dad0bcd020fc70eb5.tar.xz linux-dev-0670010f3b10aeaad0dfdf0dad0bcd020fc70eb5.zip | |
powerpc/32s: Enable STRICT_MODULE_RWX for the 603 core
The book3s/32 MMU doesn't support per page execution protection and
doesn't support RO protection for kernel pages.
However, on the 603 which implements software loaded TLBs, execution
protection is honored by the TLB Miss handler which doesn't load
Instruction TLB for non executable pages. And RO protection is
honored by clearing the C bit for RO pages, leading to DSI.
So on the 603, STRICT_MODULE_RWX is possible without much effort.
Don't disable STRICT_MODULE_RWX on book3s/32 and print a warning
in case STRICT_MODULE_RWX has been selected and the platform has
a Hardware HASH MMU.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1e6162f334167e75f1140082932e3a354b16daba.1642413973.git.christophe.leroy@csgroup.eu
| -rw-r--r-- | arch/powerpc/Kconfig | 2 | ||||
| -rw-r--r-- | arch/powerpc/mm/pgtable_32.c | 3 |
2 files changed, 4 insertions, 1 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 2a851d31f120..28e4047e99e8 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -135,7 +135,7 @@ config PPC select ARCH_HAS_SET_MEMORY select ARCH_HAS_STRICT_KERNEL_RWX if (PPC_BOOK3S || PPC_8xx || 40x) && !HIBERNATION select ARCH_HAS_STRICT_KERNEL_RWX if FSL_BOOKE && !HIBERNATION && !RANDOMIZE_BASE - select ARCH_HAS_STRICT_MODULE_RWX if ARCH_HAS_STRICT_KERNEL_RWX && !PPC_BOOK3S_32 + select ARCH_HAS_STRICT_MODULE_RWX if ARCH_HAS_STRICT_KERNEL_RWX select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAS_UACCESS_FLUSHCACHE select ARCH_HAS_UBSAN_SANITIZE_ALL diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c index f71ededdc02a..a56ade39dc68 100644 --- a/arch/powerpc/mm/pgtable_32.c +++ b/arch/powerpc/mm/pgtable_32.c @@ -148,6 +148,9 @@ void mark_rodata_ro(void) { unsigned long numpages; + if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX) && mmu_has_feature(MMU_FTR_HPTE_TABLE)) + pr_warn("This platform has HASH MMU, STRICT_MODULE_RWX won't work\n"); + if (v_block_mapped((unsigned long)_stext + 1)) { mmu_mark_rodata_ro(); ptdump_check_wx(); |