Messages in this thread |  | | Date | Thu, 13 Mar 2014 11:38:18 -0700 | Subject | Re: [PATCH v2] ARM: mm: fix reporting of read-only PMD bits | From | Kees Cook <> |
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On Wed, Feb 12, 2014 at 2:43 PM, Kees Cook <keescook@chromium.org> wrote: > On non-LPAE, read-only PMD bits are defined with the combination > "PMD_SECT_APX | PMD_SECT_AP_WRITE". Adjusted the bit masks to correctly > detect this. > > Signed-off-by: Kees Cook <keescook@chromium.org> > --- > v2: > - reorder bits, suggested by Olof Johansson. > --- > arch/arm/mm/dump.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/arch/arm/mm/dump.c b/arch/arm/mm/dump.c > index 2b3a56414271..2b342177f5de 100644 > --- a/arch/arm/mm/dump.c > +++ b/arch/arm/mm/dump.c > @@ -123,19 +123,19 @@ static const struct prot_bits section_bits[] = { > #ifndef CONFIG_ARM_LPAE > /* These are approximate */ > { > - .mask = PMD_SECT_AP_READ | PMD_SECT_AP_WRITE, > - .val = 0, > + .mask = PMD_SECT_APX | PMD_SECT_AP_READ | PMD_SECT_AP_WRITE, > + .val = PMD_SECT_APX | PMD_SECT_AP_WRITE, > .set = " ro", > }, {
As Russell pointed out, this won't be valid for pre-v6 CPUs. What's the best config for handling this? I'd like something like CONFIG_ARM_LPAE, but using the CPU_* stuff seems a bit sloppy:
#if !defined(CONFIG_ARM_CPU_V6) && !defined(CONFIG_ARM_CPU_V7) ...new masks... #else ...old masks... #endif
But that seems to be the only thing I can find. Is CPU_* good enough here?
-Kees
> - .mask = PMD_SECT_AP_READ | PMD_SECT_AP_WRITE, > + .mask = PMD_SECT_APX | PMD_SECT_AP_READ | PMD_SECT_AP_WRITE, > .val = PMD_SECT_AP_WRITE, > .set = " RW", > }, { > - .mask = PMD_SECT_AP_READ | PMD_SECT_AP_WRITE, > + .mask = PMD_SECT_APX | PMD_SECT_AP_READ | PMD_SECT_AP_WRITE, > .val = PMD_SECT_AP_READ, > .set = "USR ro", > }, { > - .mask = PMD_SECT_AP_READ | PMD_SECT_AP_WRITE, > + .mask = PMD_SECT_APX | PMD_SECT_AP_READ | PMD_SECT_AP_WRITE, > .val = PMD_SECT_AP_READ | PMD_SECT_AP_WRITE, > .set = "USR RW", > #else > -- > 1.7.9.5 > > > -- > Kees Cook > Chrome OS Security
-- Kees Cook Chrome OS Security
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