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 --- v4: Added more details in commit message following comment from Michael. v3: Fixed build failure reported by robots. --- fs/proc/task_mmu.c | 4 +++- include/linux/mm.h | 4 +++- include/trace/events/mmflags.h | 4 ++-- 3 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 5f171ad7b436..3a07e13e2f81 100644 --- 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 6549d0979b28..028847f39442 100644 --- 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 b63d211bd141..37265977d524 100644 --- 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)