From 4d4fe8f2b27ceb29c16b32c3882ebd19bf21800f Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 27 Apr 2016 17:47:11 +0100 Subject: PM / Hibernate: Call flush_icache_range() on pages restored in-place Some architectures require code written to memory as if it were data to be 'cleaned' from any data caches before the processor can fetch them as new instructions. During resume from hibernate, the snapshot code copies some pages directly, meaning these architectures do not get a chance to perform their cache maintenance. Modify the read and decompress code to call flush_icache_range() on all pages that are restored, so that the restored in-place pages are guaranteed to be executable on these architectures. Signed-off-by: James Morse Acked-by: Pavel Machek Acked-by: Rafael J. Wysocki Acked-by: Catalin Marinas [will: make clean_pages_on_* static and remove initialisers] Signed-off-by: Will Deacon (cherry picked from commit f6cf0545ec697ddc278b7457b7d0c0d86a2ea88e) Signed-off-by: Alex Shi --- kernel/power/swap.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'kernel') diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 12cd989dadf6..160e1006640d 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -36,6 +36,14 @@ #define HIBERNATE_SIG "S1SUSPEND" +/* + * When reading an {un,}compressed image, we may restore pages in place, + * in which case some architectures need these pages cleaning before they + * can be executed. We don't know which pages these may be, so clean the lot. + */ +static bool clean_pages_on_read; +static bool clean_pages_on_decompress; + /* * The swap map is a data structure used for keeping track of each page * written to a swap partition. It consists of many swap_map_page @@ -241,6 +249,9 @@ static void hib_end_io(struct bio *bio) if (bio_data_dir(bio) == WRITE) put_page(page); + else if (clean_pages_on_read) + flush_icache_range((unsigned long)page_address(page), + (unsigned long)page_address(page) + PAGE_SIZE); if (bio->bi_error && !hb->error) hb->error = bio->bi_error; @@ -1049,6 +1060,7 @@ static int load_image(struct swap_map_handle *handle, hib_init_batch(&hb); + clean_pages_on_read = true; printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n", nr_to_read); m = nr_to_read / 10; @@ -1124,6 +1136,10 @@ static int lzo_decompress_threadfn(void *data) d->unc_len = LZO_UNC_SIZE; d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len, d->unc, &d->unc_len); + if (clean_pages_on_decompress) + flush_icache_range((unsigned long)d->unc, + (unsigned long)d->unc + d->unc_len); + atomic_set(&d->stop, 1); wake_up(&d->done); } @@ -1189,6 +1205,8 @@ static int load_image_lzo(struct swap_map_handle *handle, } memset(crc, 0, offsetof(struct crc_data, go)); + clean_pages_on_decompress = true; + /* * Start the decompression threads. */ -- cgit v1.2.3 From 3eb846e0d5ebc563d111ea825e55ea1b731b1a8b Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 2 Jan 2016 03:09:16 +0100 Subject: PM / sleep: Add support for read-only sysfs attributes Some sysfs attributes in /sys/power/ should really be read-only, so add support for that, convert those attributes to read-only and drop the stub .show() routines from them. Original-by: Sergey Senozhatsky Signed-off-by: Rafael J. Wysocki (cherry picked from commit a1e9ca6967d68209c70e616a224efa89a6b86ca6) Signed-off-by: Alex Shi --- kernel/power/main.c | 17 ++--------------- kernel/power/power.h | 9 +++++++++ 2 files changed, 11 insertions(+), 15 deletions(-) (limited to 'kernel') diff --git a/kernel/power/main.c b/kernel/power/main.c index b2dd4d999900..27946975eff0 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -280,13 +280,7 @@ static ssize_t pm_wakeup_irq_show(struct kobject *kobj, return pm_wakeup_irq ? sprintf(buf, "%u\n", pm_wakeup_irq) : -ENODATA; } -static ssize_t pm_wakeup_irq_store(struct kobject *kobj, - struct kobj_attribute *attr, - const char *buf, size_t n) -{ - return -EINVAL; -} -power_attr(pm_wakeup_irq); +power_attr_ro(pm_wakeup_irq); #else /* !CONFIG_PM_SLEEP_DEBUG */ static inline void pm_print_times_init(void) {} @@ -564,14 +558,7 @@ static ssize_t pm_trace_dev_match_show(struct kobject *kobj, return show_trace_dev_match(buf, PAGE_SIZE); } -static ssize_t -pm_trace_dev_match_store(struct kobject *kobj, struct kobj_attribute *attr, - const char *buf, size_t n) -{ - return -EINVAL; -} - -power_attr(pm_trace_dev_match); +power_attr_ro(pm_trace_dev_match); #endif /* CONFIG_PM_TRACE */ diff --git a/kernel/power/power.h b/kernel/power/power.h index caadb566e82b..efe1b3b17c88 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -77,6 +77,15 @@ static struct kobj_attribute _name##_attr = { \ .store = _name##_store, \ } +#define power_attr_ro(_name) \ +static struct kobj_attribute _name##_attr = { \ + .attr = { \ + .name = __stringify(_name), \ + .mode = S_IRUGO, \ + }, \ + .show = _name##_show, \ +} + /* Preferred image size in bytes (default 500 MB) */ extern unsigned long image_size; /* Size of memory reserved for drivers (default SPARE_PAGES x PAGE_SIZE) */ -- cgit v1.2.3 From 603c78000f8c9e813f9399619c97be105c820585 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 15 Mar 2016 00:21:06 +0100 Subject: cgroup: avoid false positive gcc-6 warning commit cfe02a8a973e7e5f66926b8ae38dfce404b19e29 upstream. When all subsystems are disabled, gcc notices that cgroup_subsys_enabled_key is a zero-length array and that any access to it must be out of bounds: In file included from ../include/linux/cgroup.h:19:0, from ../kernel/cgroup.c:31: ../kernel/cgroup.c: In function 'cgroup_add_cftypes': ../kernel/cgroup.c:261:53: error: array subscript is above array bounds [-Werror=array-bounds] return static_key_enabled(cgroup_subsys_enabled_key[ssid]); ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~ ../include/linux/jump_label.h:271:40: note: in definition of macro 'static_key_enabled' static_key_count((struct static_key *)x) > 0; \ ^ We should never call the function in this particular case, so this is not a bug. In order to silence the warning, this adds an explicit check for the CGROUP_SUBSYS_COUNT==0 case. Signed-off-by: Arnd Bergmann Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- kernel/cgroup.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index a3424f28aaf4..127c63e02d52 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -236,6 +236,9 @@ static int cgroup_addrm_files(struct cgroup_subsys_state *css, */ static bool cgroup_ssid_enabled(int ssid) { + if (CGROUP_SUBSYS_COUNT == 0) + return false; + return static_key_enabled(cgroup_subsys_enabled_key[ssid]); } -- cgit v1.2.3