Commit d175ee98 authored by Christophe Leroy's avatar Christophe Leroy Committed by Jason A. Donenfeld
Browse files

mm: Define VM_DROPPABLE for powerpc/32 



Commit 9651fced ("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: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
parent c7304938

fs/proc/task_mmu.c

+3 −1
Original line number Diff line number Diff line
@@ -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

	};

include/linux/mm.h

+3 −1
Original line number Diff line number Diff line
@@ -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

include/trace/events/mmflags.h

+2 −2
Original line number Diff line number Diff line
@@ -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)