| Message ID | 20140212224638.GA4558@www.outflux.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Feb 12, 2014 at 10:46:38PM +0000, Kees Cook wrote: > diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h > index 03243f7eeddf..fb3de59ee811 100644 > --- a/arch/arm/include/asm/pgtable-3level.h > +++ b/arch/arm/include/asm/pgtable-3level.h > @@ -138,10 +138,6 @@ > #define pud_none(pud) (!pud_val(pud)) > #define pud_bad(pud) (!(pud_val(pud) & 2)) > #define pud_present(pud) (pud_val(pud)) > -#define pmd_table(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ > - PMD_TYPE_TABLE) > -#define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ > - PMD_TYPE_SECT) > #define pmd_large(pmd) pmd_sect(pmd) > > #define pud_clear(pudp) \ > diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h > index 7d59b524f2af..934aa5b60c7c 100644 > --- a/arch/arm/include/asm/pgtable.h > +++ b/arch/arm/include/asm/pgtable.h > @@ -183,6 +183,10 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; > > #define pmd_none(pmd) (!pmd_val(pmd)) > #define pmd_present(pmd) (pmd_val(pmd)) > +#define pmd_table(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ > + PMD_TYPE_TABLE) > +#define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ > + PMD_TYPE_SECT) Do you still need to move these two if you only use pmd_large()? AFAICT, it is equivalent to pmd_sect(). > static inline pte_t *pmd_page_vaddr(pmd_t pmd) > { > diff --git a/arch/arm/mm/dump.c b/arch/arm/mm/dump.c > index 2b342177f5de..32635b474832 100644 > --- a/arch/arm/mm/dump.c > +++ b/arch/arm/mm/dump.c > @@ -260,8 +260,14 @@ static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start) > > for (i = 0; i < PTRS_PER_PMD; i++, pmd++) { > addr = start + i * PMD_SIZE; > - if (pmd_none(*pmd) || pmd_large(*pmd) || !pmd_present(*pmd)) > + if (pmd_none(*pmd) || pmd_large(*pmd) || !pmd_present(*pmd)) { > note_page(st, addr, 3, pmd_val(*pmd)); > + if (SECTION_SIZE < PMD_SIZE && > + pmd_sect(*pmd) && pmd_sect(pmd[1])) { I think the first patch was better with pmd[0] and pmd[1] treated independently if SECTION_SIZE < PMD_SIZE, only that it should have checked for pmd_sect(pmd[1]). I don't see anything in __map_init_section() that would prevent populating only the second pmd leaving the first one empty.
On Thu, Feb 13, 2014 at 9:12 AM, Catalin Marinas <catalin.marinas@arm.com> wrote: > On Wed, Feb 12, 2014 at 10:46:38PM +0000, Kees Cook wrote: >> diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h >> index 03243f7eeddf..fb3de59ee811 100644 >> --- a/arch/arm/include/asm/pgtable-3level.h >> +++ b/arch/arm/include/asm/pgtable-3level.h >> @@ -138,10 +138,6 @@ >> #define pud_none(pud) (!pud_val(pud)) >> #define pud_bad(pud) (!(pud_val(pud) & 2)) >> #define pud_present(pud) (pud_val(pud)) >> -#define pmd_table(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ >> - PMD_TYPE_TABLE) >> -#define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ >> - PMD_TYPE_SECT) >> #define pmd_large(pmd) pmd_sect(pmd) >> >> #define pud_clear(pudp) \ >> diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h >> index 7d59b524f2af..934aa5b60c7c 100644 >> --- a/arch/arm/include/asm/pgtable.h >> +++ b/arch/arm/include/asm/pgtable.h >> @@ -183,6 +183,10 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; >> >> #define pmd_none(pmd) (!pmd_val(pmd)) >> #define pmd_present(pmd) (pmd_val(pmd)) >> +#define pmd_table(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ >> + PMD_TYPE_TABLE) >> +#define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ >> + PMD_TYPE_SECT) > > Do you still need to move these two if you only use pmd_large()? AFAICT, > it is equivalent to pmd_sect(). Why does pmd_sect exist? I can reduce it to just using pmd_large. > >> static inline pte_t *pmd_page_vaddr(pmd_t pmd) >> { >> diff --git a/arch/arm/mm/dump.c b/arch/arm/mm/dump.c >> index 2b342177f5de..32635b474832 100644 >> --- a/arch/arm/mm/dump.c >> +++ b/arch/arm/mm/dump.c >> @@ -260,8 +260,14 @@ static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start) >> >> for (i = 0; i < PTRS_PER_PMD; i++, pmd++) { >> addr = start + i * PMD_SIZE; >> - if (pmd_none(*pmd) || pmd_large(*pmd) || !pmd_present(*pmd)) >> + if (pmd_none(*pmd) || pmd_large(*pmd) || !pmd_present(*pmd)) { >> note_page(st, addr, 3, pmd_val(*pmd)); >> + if (SECTION_SIZE < PMD_SIZE && >> + pmd_sect(*pmd) && pmd_sect(pmd[1])) { > > I think the first patch was better with pmd[0] and pmd[1] treated > independently if SECTION_SIZE < PMD_SIZE, only that it should have > checked for pmd_sect(pmd[1]). I don't see anything in > __map_init_section() that would prevent populating only the second pmd > leaving the first one empty. Ah, gotcha. Okay, I will send a new version. Thanks! -Kees
On Thu, Feb 13, 2014 at 07:52:03PM +0000, Kees Cook wrote: > On Thu, Feb 13, 2014 at 9:12 AM, Catalin Marinas > <catalin.marinas@arm.com> wrote: > > On Wed, Feb 12, 2014 at 10:46:38PM +0000, Kees Cook wrote: > >> diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h > >> index 03243f7eeddf..fb3de59ee811 100644 > >> --- a/arch/arm/include/asm/pgtable-3level.h > >> +++ b/arch/arm/include/asm/pgtable-3level.h > >> @@ -138,10 +138,6 @@ > >> #define pud_none(pud) (!pud_val(pud)) > >> #define pud_bad(pud) (!(pud_val(pud) & 2)) > >> #define pud_present(pud) (pud_val(pud)) > >> -#define pmd_table(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ > >> - PMD_TYPE_TABLE) > >> -#define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ > >> - PMD_TYPE_SECT) > >> #define pmd_large(pmd) pmd_sect(pmd) > >> > >> #define pud_clear(pudp) \ > >> diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h > >> index 7d59b524f2af..934aa5b60c7c 100644 > >> --- a/arch/arm/include/asm/pgtable.h > >> +++ b/arch/arm/include/asm/pgtable.h > >> @@ -183,6 +183,10 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; > >> > >> #define pmd_none(pmd) (!pmd_val(pmd)) > >> #define pmd_present(pmd) (pmd_val(pmd)) > >> +#define pmd_table(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ > >> + PMD_TYPE_TABLE) > >> +#define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ > >> + PMD_TYPE_SECT) > > > > Do you still need to move these two if you only use pmd_large()? AFAICT, > > it is equivalent to pmd_sect(). > > Why does pmd_sect exist? I can reduce it to just using pmd_large. pmd_sect/pmd_table were there first and used by kvm. The pmd_large() was added by Russell because the dump.c code was derived from x86 which uses such macro. And we have another close relative, pmd_huge(), though only defined if CONFIG_HUGETLB_PAGE. We could drop pmd_large() in favour of pmd_sect() but it's up to Russell. OTOH, when someone will try to add arm64 support, I'll most likely ask for part of the x86 code to be turned into a generic library and we'll need some common naming for such macros (e.g. pmd_large()).
diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h index 03243f7eeddf..fb3de59ee811 100644 --- a/arch/arm/include/asm/pgtable-3level.h +++ b/arch/arm/include/asm/pgtable-3level.h @@ -138,10 +138,6 @@ #define pud_none(pud) (!pud_val(pud)) #define pud_bad(pud) (!(pud_val(pud) & 2)) #define pud_present(pud) (pud_val(pud)) -#define pmd_table(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ - PMD_TYPE_TABLE) -#define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ - PMD_TYPE_SECT) #define pmd_large(pmd) pmd_sect(pmd) #define pud_clear(pudp) \ diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h index 7d59b524f2af..934aa5b60c7c 100644 --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -183,6 +183,10 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; #define pmd_none(pmd) (!pmd_val(pmd)) #define pmd_present(pmd) (pmd_val(pmd)) +#define pmd_table(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ + PMD_TYPE_TABLE) +#define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ + PMD_TYPE_SECT) static inline pte_t *pmd_page_vaddr(pmd_t pmd) { diff --git a/arch/arm/mm/dump.c b/arch/arm/mm/dump.c index 2b342177f5de..32635b474832 100644 --- a/arch/arm/mm/dump.c +++ b/arch/arm/mm/dump.c @@ -260,8 +260,14 @@ static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start) for (i = 0; i < PTRS_PER_PMD; i++, pmd++) { addr = start + i * PMD_SIZE; - if (pmd_none(*pmd) || pmd_large(*pmd) || !pmd_present(*pmd)) + if (pmd_none(*pmd) || pmd_large(*pmd) || !pmd_present(*pmd)) { note_page(st, addr, 3, pmd_val(*pmd)); + if (SECTION_SIZE < PMD_SIZE && + pmd_sect(*pmd) && pmd_sect(pmd[1])) { + note_page(st, addr + SECTION_SIZE, 3, + pmd_val(pmd[1])); + } + } else walk_pte(st, pmd, addr); }
On 2-level page table systems, the PMD has 2 section entries. Report these, otherwise ARM_PTDUMP will miss reporting permission changes on odd section boundaries. Signed-off-by: Kees Cook <keescook@chromium.org> --- v2: - reorganize, suggested by Catalin Marinas. --- arch/arm/include/asm/pgtable-3level.h | 4 ---- arch/arm/include/asm/pgtable.h | 4 ++++ arch/arm/mm/dump.c | 8 +++++++- 3 files changed, 11 insertions(+), 5 deletions(-)