diff options
| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2022-01-17 13:06:39 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-02-12 14:47:42 +0300 |
| commit | 0670010f3b10aeaad0dfdf0dad0bcd020fc70eb5 (patch) | |
| tree | ef1260794144f7f69fbbb0a12e4740fc32ae727b /arch/powerpc/mm | |
| parent | a8936569a07bf27cc9cfc2a39a1e5ea91273b2d4 (diff) | |
| download | linux-0670010f3b10aeaad0dfdf0dad0bcd020fc70eb5.tar.xz | |
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
Diffstat (limited to 'arch/powerpc/mm')
| -rw-r--r-- | arch/powerpc/mm/pgtable_32.c | 3 |
1 files changed, 3 insertions, 0 deletions
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(); |