From 1328710b8ec30ac552b51bf804d1fc255a1c7451 Mon Sep 17 00:00:00 2001 From: Daniel Micay Date: Wed, 10 May 2017 13:36:37 -0400 Subject: [PATCH] mark most percpu globals as __ro_after_init Moving pcpu_base_addr to this section comes from PaX where it's part of KERNEXEC. This extends it to the rest of the globals only written by the init code. Signed-off-by: Daniel Micay Acked-by: Kees Cook Signed-off-by: Tejun Heo --- mm/percpu.c | 36 ++++++++++++++++++------------------ 1 file changed, 18 insertions(+), 18 deletions(-) diff --git a/mm/percpu.c b/mm/percpu.c index e0aa8ae7bde7..c03753054099 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -121,35 +121,35 @@ struct pcpu_chunk { unsigned long populated[]; /* populated bitmap */ }; -static int pcpu_unit_pages __read_mostly; -static int pcpu_unit_size __read_mostly; -static int pcpu_nr_units __read_mostly; -static int pcpu_atom_size __read_mostly; -static int pcpu_nr_slots __read_mostly; -static size_t pcpu_chunk_struct_size __read_mostly; +static int pcpu_unit_pages __ro_after_init; +static int pcpu_unit_size __ro_after_init; +static int pcpu_nr_units __ro_after_init; +static int pcpu_atom_size __ro_after_init; +static int pcpu_nr_slots __ro_after_init; +static size_t pcpu_chunk_struct_size __ro_after_init; /* cpus with the lowest and highest unit addresses */ -static unsigned int pcpu_low_unit_cpu __read_mostly; -static unsigned int pcpu_high_unit_cpu __read_mostly; +static unsigned int pcpu_low_unit_cpu __ro_after_init; +static unsigned int pcpu_high_unit_cpu __ro_after_init; /* the address of the first chunk which starts with the kernel static area */ -void *pcpu_base_addr __read_mostly; +void *pcpu_base_addr __ro_after_init; EXPORT_SYMBOL_GPL(pcpu_base_addr); -static const int *pcpu_unit_map __read_mostly; /* cpu -> unit */ -const unsigned long *pcpu_unit_offsets __read_mostly; /* cpu -> unit offset */ +static const int *pcpu_unit_map __ro_after_init; /* cpu -> unit */ +const unsigned long *pcpu_unit_offsets __ro_after_init; /* cpu -> unit offset */ /* group information, used for vm allocation */ -static int pcpu_nr_groups __read_mostly; -static const unsigned long *pcpu_group_offsets __read_mostly; -static const size_t *pcpu_group_sizes __read_mostly; +static int pcpu_nr_groups __ro_after_init; +static const unsigned long *pcpu_group_offsets __ro_after_init; +static const size_t *pcpu_group_sizes __ro_after_init; /* * The first chunk which always exists. Note that unlike other * chunks, this one can be allocated and mapped in several different * ways and thus often doesn't live in the vmalloc area. */ -static struct pcpu_chunk *pcpu_first_chunk; +static struct pcpu_chunk *pcpu_first_chunk __ro_after_init; /* * Optional reserved chunk. This chunk reserves part of the first @@ -158,13 +158,13 @@ static struct pcpu_chunk *pcpu_first_chunk; * area doesn't exist, the following variables contain NULL and 0 * respectively. */ -static struct pcpu_chunk *pcpu_reserved_chunk; -static int pcpu_reserved_chunk_limit; +static struct pcpu_chunk *pcpu_reserved_chunk __ro_after_init; +static int pcpu_reserved_chunk_limit __ro_after_init; static DEFINE_SPINLOCK(pcpu_lock); /* all internal data structures */ static DEFINE_MUTEX(pcpu_alloc_mutex); /* chunk create/destroy, [de]pop, map ext */ -static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */ +static struct list_head *pcpu_slot __ro_after_init; /* chunk list slots */ /* chunks which need their map areas extended, protected by pcpu_lock */ static LIST_HEAD(pcpu_map_extend_chunks); -- 2.20.1