mm: Define VM_DROPPABLE for powerpc/32

Commit 9651fcedf7b9 ("mm: add MAP_DROPPABLE for designating always
lazily freeable mappings") only adds VM_DROPPABLE for 64 bits
architectures.

In order to also use the getrandom vDSO implementation on powerpc/32,
use VM_ARCH_1 for VM_DROPPABLE on powerpc/32. This is possible because
VM_ARCH_1 is used for VM_SAO on powerpc and VM_SAO is only for
powerpc/64. It is used in combination with PROT_SAO in some parts of
code that are restricted to CONFIG_PPC64 through #ifdefs, it is
therefore possible to define VM_SAO for CONFIG_PPC64 only.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 5f171ad7b436be5915e4564afba2c680a209c777..3a07e13e2f818a2463c6a66d49a9aa90d2705487 100644 (file)
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -987,8 +987,10 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
 #ifdef CONFIG_X86_USER_SHADOW_STACK
                [ilog2(VM_SHADOW_STACK)] = "ss",
 #endif
-#ifdef CONFIG_64BIT
+#if defined(CONFIG_64BIT) || defined(CONFIG_PPC32)
                [ilog2(VM_DROPPABLE)] = "dp",
+#endif
+#ifdef CONFIG_64BIT
                [ilog2(VM_SEALED)] = "sl",
 #endif
        };

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 6549d0979b28f93332db0457bfa70942ff2cf43a..028847f3944284daa842511c670584c8645d29c3 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -359,7 +359,7 @@ extern unsigned int kobjsize(const void *objp);
 
 #if defined(CONFIG_X86)
 # define VM_PAT                VM_ARCH_1       /* PAT reserves whole VMA at once (x86) */
-#elif defined(CONFIG_PPC)
+#elif defined(CONFIG_PPC64)
 # define VM_SAO                VM_ARCH_1       /* Strong Access Ordering (powerpc) */
 #elif defined(CONFIG_PARISC)
 # define VM_GROWSUP    VM_ARCH_1
@@ -409,6 +409,8 @@ extern unsigned int kobjsize(const void *objp);
 #ifdef CONFIG_64BIT
 #define VM_DROPPABLE_BIT       40
 #define VM_DROPPABLE           BIT(VM_DROPPABLE_BIT)
+#elif defined(CONFIG_PPC32)
+#define VM_DROPPABLE           VM_ARCH_1
 #else
 #define VM_DROPPABLE           VM_NONE
 #endif

diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index b63d211bd14152f4c747ff2107747a5c83598bb3..37265977d5246aa4def5366417a9985a715dfac3 100644 (file)
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -143,7 +143,7 @@ IF_HAVE_PG_ARCH_X(arch_3)
 
 #if defined(CONFIG_X86)
 #define __VM_ARCH_SPECIFIC_1 {VM_PAT,     "pat"           }
-#elif defined(CONFIG_PPC)
+#elif defined(CONFIG_PPC64)
 #define __VM_ARCH_SPECIFIC_1 {VM_SAO,     "sao"           }
 #elif defined(CONFIG_PARISC)
 #define __VM_ARCH_SPECIFIC_1 {VM_GROWSUP,      "growsup"       }
@@ -165,7 +165,7 @@ IF_HAVE_PG_ARCH_X(arch_3)
 # define IF_HAVE_UFFD_MINOR(flag, name)
 #endif
 
-#ifdef CONFIG_64BIT
+#if defined(CONFIG_64BIT) || defined(CONFIG_PPC32)
 # define IF_HAVE_VM_DROPPABLE(flag, name) {flag, name},
 #else
 # define IF_HAVE_VM_DROPPABLE(flag, name)