| Message ID | 8736kb9fry.fsf_-_@igel.home (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | powerpc/mm/32s: only use MMU to mark initmem NX if STRICT_KERNEL_RWX | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch next (a3bf9fbdad600b1e4335dd90979f8d6072e4f602) |
| snowpatch_ozlabs/build-ppc64le | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64be | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
| snowpatch_ozlabs/build-pmac32 | success | Build succeeded |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 12 lines checked |
Andreas Schwab <schwab@linux-m68k.org> a écrit : > If STRICT_KERNEL_RWX is disabled, never use the MMU to mark initmen > nonexecutable. I dont understand, can you elaborate ? This area is mapped with BATs so using change_page_attr() is pointless. Christophe > > Also move a misplaced paren that makes the condition always true. > > Fixes: 63b2bc619565 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX") > Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> > --- > arch/powerpc/mm/pgtable_32.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c > index d53188dee18f..3935dc263d65 100644 > --- a/arch/powerpc/mm/pgtable_32.c > +++ b/arch/powerpc/mm/pgtable_32.c > @@ -360,9 +360,11 @@ void mark_initmem_nx(void) > unsigned long numpages = PFN_UP((unsigned long)_einittext) - > PFN_DOWN((unsigned long)_sinittext); > > - if (v_block_mapped((unsigned long)_stext) + 1) > +#ifdef CONFIG_STRICT_KERNEL_RWX > + if (v_block_mapped((unsigned long)_stext + 1)) > mmu_mark_initmem_nx(); > else > +#endif > change_page_attr(page, numpages, PAGE_KERNEL); > } > > -- > 2.22.0 > > -- > Andreas Schwab, schwab@linux-m68k.org > GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 > "And now for something completely different."
On Jun 15 2019, Christophe Leroy <christophe.leroy@c-s.fr> wrote: > Andreas Schwab <schwab@linux-m68k.org> a écrit : > >> If STRICT_KERNEL_RWX is disabled, never use the MMU to mark initmen >> nonexecutable. > > I dont understand, can you elaborate ? It breaks suspend. > This area is mapped with BATs so using change_page_attr() is pointless. There must be a reason STRICT_KERNEL_RWX is not available with HIBERNATE. Andreas.
Le 15/06/2019 à 16:36, Andreas Schwab a écrit : > On Jun 15 2019, Christophe Leroy <christophe.leroy@c-s.fr> wrote: > >> Andreas Schwab <schwab@linux-m68k.org> a écrit : >> >>> If STRICT_KERNEL_RWX is disabled, never use the MMU to mark initmen >>> nonexecutable. >> >> I dont understand, can you elaborate ? > > It breaks suspend. Ok, but we need to explain why it breaks suspend, and again your patch is wrong anyway because that area of memory is mapped with BATs so you can't use change_page_attr() > >> This area is mapped with BATs so using change_page_attr() is pointless. > > There must be a reason STRICT_KERNEL_RWX is not available with > HIBERNATE. Yes but HIBERNATE and suspend are not the same thing. I guess HIBERNATE is not available with STRICT_KERNEL_RWX because HIBERNATE have to write back saved state into read-only memory as well. Christophe --- L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast. https://www.avast.com/antivirus
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c index d53188dee18f..3935dc263d65 100644 --- a/arch/powerpc/mm/pgtable_32.c +++ b/arch/powerpc/mm/pgtable_32.c @@ -360,9 +360,11 @@ void mark_initmem_nx(void) unsigned long numpages = PFN_UP((unsigned long)_einittext) - PFN_DOWN((unsigned long)_sinittext); - if (v_block_mapped((unsigned long)_stext) + 1) +#ifdef CONFIG_STRICT_KERNEL_RWX + if (v_block_mapped((unsigned long)_stext + 1)) mmu_mark_initmem_nx(); else +#endif change_page_attr(page, numpages, PAGE_KERNEL); }
If STRICT_KERNEL_RWX is disabled, never use the MMU to mark initmen nonexecutable. Also move a misplaced paren that makes the condition always true. Fixes: 63b2bc619565 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX") Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> --- arch/powerpc/mm/pgtable_32.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)