Message ID | 20170414131126.AA07A67422@localhost.localdomain (mailing list archive) |
---|---|
State | Superseded |
Headers | show |
Christophe Leroy <christophe.leroy@c-s.fr> writes: > diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c > index 9ee536ec0739..e95931c4e6cf 100644 > --- a/arch/powerpc/mm/mem.c > +++ b/arch/powerpc/mm/mem.c > @@ -401,6 +401,9 @@ void free_initmem(void) > { > ppc_md.progress = ppc_printk_progress; > free_initmem_default(POISON_FREE_INITMEM); > +#ifdef CONFIG_PPC32 > + remap_init_ram(); > +#endif > } Please don't put ifdefs straight in C code like that unless you have to. In this case it's easy to put an empty version in a header, eg: > diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h > index f988db655e5b..d39d92600839 100644 > --- a/arch/powerpc/mm/mmu_decl.h > +++ b/arch/powerpc/mm/mmu_decl.h > @@ -95,6 +95,7 @@ extern void _tlbia(void); > > extern void mapin_ram(void); > extern int map_page(unsigned long va, phys_addr_t pa, int flags); +#ifdef CONFIG_PPC32 > +void remap_init_ram(void); +#else +static inline void remap_init_ram(void) { } +#endif > diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c > index a65c0b4c0669..d506bd61b629 100644 > --- a/arch/powerpc/mm/pgtable_32.c > +++ b/arch/powerpc/mm/pgtable_32.c > @@ -323,6 +323,26 @@ get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) > return(retval); > } > > +void remap_init_ram(void) > +{ > + unsigned long start = (unsigned long)_sinittext & PAGE_MASK; > + unsigned long end = (unsigned long)_einittext; > + unsigned long va; > + > + for (va = start; va < end; va += PAGE_SIZE) { > + pte_t *kpte; > + pmd_t *kpmd; > + pte_t pte = pfn_pte(__pa(va) >> PAGE_SHIFT, PAGE_KERNEL); > + > + if (!get_pteptr(&init_mm, va, &kpte, &kpmd)) > + continue; > + __set_pte_at(&init_mm, va, kpte, pte, 0); > + wmb(); > + pte_unmap(kpte); > + } > + flush_tlb_kernel_range(start, end); > +} Can we just use unmap_kernel_range() ? Is this sufficient on all 32-bit PPC? (I have no idea) cheers
Le 18/04/2017 à 08:40, Michael Ellerman a écrit : > Christophe Leroy <christophe.leroy@c-s.fr> writes: > > >> diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c >> index a65c0b4c0669..d506bd61b629 100644 >> --- a/arch/powerpc/mm/pgtable_32.c >> +++ b/arch/powerpc/mm/pgtable_32.c >> @@ -323,6 +323,26 @@ get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) >> return(retval); >> } >> >> +void remap_init_ram(void) >> +{ >> + unsigned long start = (unsigned long)_sinittext & PAGE_MASK; >> + unsigned long end = (unsigned long)_einittext; >> + unsigned long va; >> + >> + for (va = start; va < end; va += PAGE_SIZE) { >> + pte_t *kpte; >> + pmd_t *kpmd; >> + pte_t pte = pfn_pte(__pa(va) >> PAGE_SHIFT, PAGE_KERNEL); >> + >> + if (!get_pteptr(&init_mm, va, &kpte, &kpmd)) >> + continue; >> + __set_pte_at(&init_mm, va, kpte, pte, 0); >> + wmb(); >> + pte_unmap(kpte); >> + } >> + flush_tlb_kernel_range(start, end); >> +} > > Can we just use unmap_kernel_range() ? We only want to remove the X bit. I think unmap_kernel_range() will unmap the area, wheareas we want to keep it as part of the linear data area. Christophe > > Is this sufficient on all 32-bit PPC? (I have no idea) > > cheers >
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 9ee536ec0739..e95931c4e6cf 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -401,6 +401,9 @@ void free_initmem(void) { ppc_md.progress = ppc_printk_progress; free_initmem_default(POISON_FREE_INITMEM); +#ifdef CONFIG_PPC32 + remap_init_ram(); +#endif } #ifdef CONFIG_BLK_DEV_INITRD diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index f988db655e5b..d39d92600839 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -95,6 +95,7 @@ extern void _tlbia(void); extern void mapin_ram(void); extern int map_page(unsigned long va, phys_addr_t pa, int flags); +void remap_init_ram(void); extern void setbat(int index, unsigned long virt, phys_addr_t phys, unsigned int size, pgprot_t prot); diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c index a65c0b4c0669..d506bd61b629 100644 --- a/arch/powerpc/mm/pgtable_32.c +++ b/arch/powerpc/mm/pgtable_32.c @@ -323,6 +323,26 @@ get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) return(retval); } +void remap_init_ram(void) +{ + unsigned long start = (unsigned long)_sinittext & PAGE_MASK; + unsigned long end = (unsigned long)_einittext; + unsigned long va; + + for (va = start; va < end; va += PAGE_SIZE) { + pte_t *kpte; + pmd_t *kpmd; + pte_t pte = pfn_pte(__pa(va) >> PAGE_SHIFT, PAGE_KERNEL); + + if (!get_pteptr(&init_mm, va, &kpte, &kpmd)) + continue; + __set_pte_at(&init_mm, va, kpte, pte, 0); + wmb(); + pte_unmap(kpte); + } + flush_tlb_kernel_range(start, end); +} + #ifdef CONFIG_DEBUG_PAGEALLOC static int __change_page_attr(struct page *page, pgprot_t prot)
As seen below, allthough the init sections have been freed, the associated memory area is still marked as executable in the page tables. This patch fixes that. [ 5.860093] Freeing unused kernel memory: 592K (c0570000 - c0604000) ---[ Start of kernel VM ]--- 0xc0000000-0xc0497fff 4704K rw X present dirty accessed shared 0xc0498000-0xc056ffff 864K rw present dirty accessed shared 0xc0570000-0xc059ffff 192K rw X present dirty accessed shared 0xc05a0000-0xc7ffffff 125312K rw present dirty accessed shared ---[ vmalloc() Area ]--- Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> --- arch/powerpc/mm/mem.c | 3 +++ arch/powerpc/mm/mmu_decl.h | 1 + arch/powerpc/mm/pgtable_32.c | 20 ++++++++++++++++++++ 3 files changed, 24 insertions(+)