From f0c7183008b41e92fa676406d87f18773724b48b Mon Sep 17 00:00:00 2001 From: Brian Geffon Date: Thu, 21 Sep 2023 13:00:45 -0400 Subject: [PATCH 1/4] PM: hibernate: Use __get_safe_page() rather than touching the list We found at least one situation where the safe pages list was empty and get_buffer() would gladly try to use a NULL pointer. Signed-off-by: Brian Geffon Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem") Cc: All applicable Signed-off-by: Rafael J. Wysocki --- kernel/power/snapshot.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 87e9f7e2bdc0..acd2e49b9ac8 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -2545,8 +2545,9 @@ static void *get_highmem_page_buffer(struct page *page, pbe->copy_page = tmp; } else { /* Copy of the page will be stored in normal memory */ - kaddr = safe_pages_list; - safe_pages_list = safe_pages_list->next; + kaddr = __get_safe_page(ca->gfp_mask); + if (!kaddr) + return ERR_PTR(-ENOMEM); pbe->copy_page = virt_to_page(kaddr); } pbe->next = highmem_pblist; @@ -2750,8 +2751,9 @@ static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca) return ERR_PTR(-ENOMEM); } pbe->orig_address = page_address(page); - pbe->address = safe_pages_list; - safe_pages_list = safe_pages_list->next; + pbe->address = __get_safe_page(ca->gfp_mask); + if (!pbe->address) + return ERR_PTR(-ENOMEM); pbe->next = restore_pblist; restore_pblist = pbe; return pbe->address; From 8d74f1da776da9b0306630b13a3025214fa44618 Mon Sep 17 00:00:00 2001 From: Raag Jadav Date: Fri, 22 Sep 2023 11:15:52 +0530 Subject: [PATCH 2/4] PM: sleep: Fix symbol export for _SIMPLE_ variants of _PM_OPS() Currently EXPORT_*_SIMPLE_DEV_PM_OPS() use EXPORT_*_DEV_PM_OPS() set of macros to export dev_pm_ops symbol, which export the symbol in case CONFIG_PM=y but don't take CONFIG_PM_SLEEP into consideration. Since _SIMPLE_ variants of _PM_OPS() do not include runtime PM handles and are only used in case CONFIG_PM_SLEEP=y, we should not be exporting dev_pm_ops symbol for them in case CONFIG_PM_SLEEP=n. This can be fixed by having two distinct set of export macros for both _RUNTIME_ and _SIMPLE_ variants of _PM_OPS(), such that the export of dev_pm_ops symbol used in each variant depends on CONFIG_PM and CONFIG_PM_SLEEP respectively. Introduce _DEV_SLEEP_PM_OPS() set of export macros for _SIMPLE_ variants of _PM_OPS(), which export dev_pm_ops symbol only in case CONFIG_PM_SLEEP=y and discard it otherwise. Fixes: 34e1ed189fab ("PM: Improve EXPORT_*_DEV_PM_OPS macros") Signed-off-by: Raag Jadav Reviewed-by: Paul Cercueil Signed-off-by: Rafael J. Wysocki --- include/linux/pm.h | 43 +++++++++++++++++++++++++++++-------------- 1 file changed, 29 insertions(+), 14 deletions(-) diff --git a/include/linux/pm.h b/include/linux/pm.h index 1400c37b29c7..629c1633bbd0 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -374,24 +374,39 @@ const struct dev_pm_ops name = { \ RUNTIME_PM_OPS(runtime_suspend_fn, runtime_resume_fn, idle_fn) \ } -#ifdef CONFIG_PM -#define _EXPORT_DEV_PM_OPS(name, license, ns) \ +#define _EXPORT_PM_OPS(name, license, ns) \ const struct dev_pm_ops name; \ __EXPORT_SYMBOL(name, license, ns); \ const struct dev_pm_ops name -#define EXPORT_PM_FN_GPL(name) EXPORT_SYMBOL_GPL(name) -#define EXPORT_PM_FN_NS_GPL(name, ns) EXPORT_SYMBOL_NS_GPL(name, ns) -#else -#define _EXPORT_DEV_PM_OPS(name, license, ns) \ + +#define _DISCARD_PM_OPS(name, license, ns) \ static __maybe_unused const struct dev_pm_ops __static_##name + +#ifdef CONFIG_PM +#define _EXPORT_DEV_PM_OPS(name, license, ns) _EXPORT_PM_OPS(name, license, ns) +#define EXPORT_PM_FN_GPL(name) EXPORT_SYMBOL_GPL(name) +#define EXPORT_PM_FN_NS_GPL(name, ns) EXPORT_SYMBOL_NS_GPL(name, ns) +#else +#define _EXPORT_DEV_PM_OPS(name, license, ns) _DISCARD_PM_OPS(name, license, ns) #define EXPORT_PM_FN_GPL(name) #define EXPORT_PM_FN_NS_GPL(name, ns) #endif -#define EXPORT_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name, "", "") -#define EXPORT_GPL_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name, "GPL", "") -#define EXPORT_NS_DEV_PM_OPS(name, ns) _EXPORT_DEV_PM_OPS(name, "", #ns) -#define EXPORT_NS_GPL_DEV_PM_OPS(name, ns) _EXPORT_DEV_PM_OPS(name, "GPL", #ns) +#ifdef CONFIG_PM_SLEEP +#define _EXPORT_DEV_SLEEP_PM_OPS(name, license, ns) _EXPORT_PM_OPS(name, license, ns) +#else +#define _EXPORT_DEV_SLEEP_PM_OPS(name, license, ns) _DISCARD_PM_OPS(name, license, ns) +#endif + +#define EXPORT_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name, "", "") +#define EXPORT_GPL_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name, "GPL", "") +#define EXPORT_NS_DEV_PM_OPS(name, ns) _EXPORT_DEV_PM_OPS(name, "", #ns) +#define EXPORT_NS_GPL_DEV_PM_OPS(name, ns) _EXPORT_DEV_PM_OPS(name, "GPL", #ns) + +#define EXPORT_DEV_SLEEP_PM_OPS(name) _EXPORT_DEV_SLEEP_PM_OPS(name, "", "") +#define EXPORT_GPL_DEV_SLEEP_PM_OPS(name) _EXPORT_DEV_SLEEP_PM_OPS(name, "GPL", "") +#define EXPORT_NS_DEV_SLEEP_PM_OPS(name, ns) _EXPORT_DEV_SLEEP_PM_OPS(name, "", #ns) +#define EXPORT_NS_GPL_DEV_SLEEP_PM_OPS(name, ns) _EXPORT_DEV_SLEEP_PM_OPS(name, "GPL", #ns) /* * Use this if you want to use the same suspend and resume callbacks for suspend @@ -404,19 +419,19 @@ const struct dev_pm_ops name = { \ _DEFINE_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL) #define EXPORT_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \ - EXPORT_DEV_PM_OPS(name) = { \ + EXPORT_DEV_SLEEP_PM_OPS(name) = { \ SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \ } #define EXPORT_GPL_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \ - EXPORT_GPL_DEV_PM_OPS(name) = { \ + EXPORT_GPL_DEV_SLEEP_PM_OPS(name) = { \ SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \ } #define EXPORT_NS_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn, ns) \ - EXPORT_NS_DEV_PM_OPS(name, ns) = { \ + EXPORT_NS_DEV_SLEEP_PM_OPS(name, ns) = { \ SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \ } #define EXPORT_NS_GPL_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn, ns) \ - EXPORT_NS_GPL_DEV_PM_OPS(name, ns) = { \ + EXPORT_NS_GPL_DEV_SLEEP_PM_OPS(name, ns) = { \ SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \ } From d08970df1980476f27936e24d452550f3e9e92e1 Mon Sep 17 00:00:00 2001 From: Brian Geffon Date: Fri, 22 Sep 2023 12:07:04 -0400 Subject: [PATCH 3/4] PM: hibernate: Clean up sync_read handling in snapshot_write_next() In snapshot_write_next(), sync_read is set and unset in three different spots unnecessiarly. As a result there is a subtle bug where the first page after the meta data has been loaded unconditionally sets sync_read to 0. If this first PFN was actually a highmem page, then the returned buffer will be the global "buffer," and the page needs to be loaded synchronously. That is, I'm not sure we can always assume the following to be safe: handle->buffer = get_buffer(&orig_bm, &ca); handle->sync_read = 0; Because get_buffer() can call get_highmem_page_buffer() which can return 'buffer'. The easiest way to address this is just set sync_read before snapshot_write_next() returns if handle->buffer == buffer. Signed-off-by: Brian Geffon Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem") Cc: All applicable [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki --- kernel/power/snapshot.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index acd2e49b9ac8..7f0e6870318b 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -2785,8 +2785,6 @@ next: if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages + nr_zero_pages) return 0; - handle->sync_read = 1; - if (!handle->cur) { if (!buffer) /* This makes the buffer be freed by swsusp_free() */ @@ -2829,7 +2827,6 @@ next: memory_bm_position_reset(&zero_bm); restore_pblist = NULL; handle->buffer = get_buffer(&orig_bm, &ca); - handle->sync_read = 0; if (IS_ERR(handle->buffer)) return PTR_ERR(handle->buffer); } @@ -2839,9 +2836,8 @@ next: handle->buffer = get_buffer(&orig_bm, &ca); if (IS_ERR(handle->buffer)) return PTR_ERR(handle->buffer); - if (handle->buffer != buffer) - handle->sync_read = 0; } + handle->sync_read = (handle->buffer == buffer); handle->cur++; /* Zero pages were not included in the image, memset it and move on. */ From 7bf770f74e850c0b8d21ac143b3b2bc18813a6eb Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 25 Sep 2023 09:40:58 +0200 Subject: [PATCH 4/4] PM: hibernate: fix the kerneldoc comment for swsusp_check() and swsusp_close() The comments for both swsusp_check() and swsusp_close() don't actually describe what they are doing. Just removing the comments would probably better, but as the file is full of useless kerneldoc comments for non-exported symbols this fits in better with the style. Signed-off-by: Christoph Hellwig Signed-off-by: Rafael J. Wysocki --- kernel/power/swap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 74edbce2320b..a64af0a552f9 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -1513,7 +1513,7 @@ end: static void *swsusp_holder; /** - * swsusp_check - Check for swsusp signature in the resume device + * swsusp_check - Open the resume device and check for the swsusp signature. * @exclusive: Open the resume device exclusively. */ @@ -1564,7 +1564,7 @@ put: } /** - * swsusp_close - close swap device. + * swsusp_close - close resume device. * @exclusive: Close the resume device which is exclusively opened. */