Le 08/04/2022 à 14:53, Christophe Leroy a écrit :
Le 07/04/2022 à 12:32, Anshuman Khandual a écrit :
This defines and exports a platform specific custom vm_get_page_prot()
via
subscribing ARCH_HAS_VM_GET_PAGE_PROT. While here, this also localizes
arch_vm_get_page_prot() as powerpc_vm_get_page_prot() and moves it near
vm_get_page_prot().
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/mman.h | 12 ------------
arch/powerpc/mm/mmap.c | 26 ++++++++++++++++++++++++++
3 files changed, 27 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 174edabb74fa..eb9b6ddbf92f 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -140,6 +140,7 @@ config PPC
select ARCH_HAS_TICK_BROADCAST if
GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UACCESS_FLUSHCACHE
select ARCH_HAS_UBSAN_SANITIZE_ALL
+ select ARCH_HAS_VM_GET_PAGE_PROT
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_KEEP_MEMBLOCK
select ARCH_MIGHT_HAVE_PC_PARPORT
diff --git a/arch/powerpc/include/asm/mman.h
b/arch/powerpc/include/asm/mman.h
index 7cb6d18f5cd6..1b024e64c8ec 100644
--- a/arch/powerpc/include/asm/mman.h
+++ b/arch/powerpc/include/asm/mman.h
@@ -24,18 +24,6 @@ static inline unsigned long
arch_calc_vm_prot_bits(unsigned long prot,
}
#define arch_calc_vm_prot_bits(prot, pkey)
arch_calc_vm_prot_bits(prot, pkey)
-static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
-{
-#ifdef CONFIG_PPC_MEM_KEYS
- return (vm_flags & VM_SAO) ?
- __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
- __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
-#else
- return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
-#endif
-}
-#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
-
static inline bool arch_validate_prot(unsigned long prot, unsigned
long addr)
{
if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM |
PROT_SAO))
diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c
index c475cf810aa8..cd17bd6fa36b 100644
--- a/arch/powerpc/mm/mmap.c
+++ b/arch/powerpc/mm/mmap.c
@@ -254,3 +254,29 @@ void arch_pick_mmap_layout(struct mm_struct *mm,
struct rlimit *rlim_stack)
mm->get_unmapped_area = arch_get_unmapped_area_topdown;
}
}
+
+#ifdef CONFIG_PPC64
+static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
+{
+#ifdef CONFIG_PPC_MEM_KEYS
+ return (vm_flags & VM_SAO) ?
+ __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
+ __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
+#else
+ return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
+#endif
+}
+#else
+static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
+{
+ return __pgprot(0);
+}
+#endif /* CONFIG_PPC64 */
Can we reduce this forest of #ifdefs and make it more readable ?
mm/mmap.c is going away with patch
https://patchwork.ozlabs.org/project/linuxppc-dev/patch/d6d849621f821af253e777a24eda4c648814a76e.1646847562.git.christophe.leroy@xxxxxxxxxx/
So it would be better to add two versions of vm_get_page_prot(), for
instance one in mm/pgtable_64.c and one in mm/pgtable_32.c
Indeed, you don't need anything at all for PPC32. All you need to do is
select ARCH_HAS_VM_GET_PAGE_PROT if PPC64
And in fact it could even be PPC_BOOK3S_64 instead of PPC64 because
CONFIG_PPC_MEM_KEYS depends on PPC_BOOK3S_64 and _PAGE_SAO is 0 on
nohash/64.
So you can then put it into arch/powerpc/mm/book3s64/pgtable.c
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+ return __pgprot(pgprot_val(protection_map[vm_flags &
+ (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
+ pgprot_val(powerpc_vm_get_page_prot(vm_flags)));
+}
+EXPORT_SYMBOL(vm_get_page_prot);
By the way I'm a bit puzzled with the name powerpc_vm_get_page_prot(),
the name suggests that it's just a powerpc replacement of
vm_get_page_prot(). I'd prefer if it was named __vm_get_page_prot(), it
would be clearer that it is a complement to vm_get_page_prot() and not a
remplacement.
Christophe
