December 2017 - Linux-stable-mirror

[Linux-stable-mirror] [linux-yocto] [yocto-4.12] [PATCH] x86/debug: Handle warnings before the notifier chain, to fix KGDB crash

by Hongzhi.Song

From: Alexander Shishkin <alexander.shishkin(a)linux.intel.com> commit b8347c2196492f4e1cccde3d92fda1cc2cc7de7e upstream Commit: 9a93848fe787 ("x86/debug: Implement __WARN() using UD0") turned warnings into UD0, but the fixup code only runs after the notify_die() chain. This is a problem, in particular, with kgdb, which kicks in as if it was a BUG(). Fix this by running the fixup code before the notifier chain in the invalid op handler path. Signed-off-by: Alexander Shishkin <alexander.shishkin(a)linux.intel.com> Tested-by: Ilya Dryomov <idryomov(a)gmail.com> Acked-by: Daniel Thompson <daniel.thompson(a)linaro.org> Acked-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Jason Wessel <jason.wessel(a)windriver.com> Cc: Arjan van de Ven <arjan(a)linux.intel.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Richard Weinberger <richard.weinberger(a)gmail.com> Cc: <stable(a)vger.kernel.org> # v4.12+ Link: http://lkml.kernel.org/r/20170724100428.19173-1-alexander.shishkin@linux.in… Signed-off-by: Ingo Molnar <mingo(a)kernel.org> This patch is to resolve the problem shown as follows, when testing KGDB with 'echo kgdbts=V1 > /sys/module/kgdbts/parameters/kgdbts': [ 196.275931] Kernel panic - not syncing: Recursive entry to debugger [ 196.276658] CPU: 0 PID: 1495 Comm: sh Not tainted 4.12.16-yocto-standard #2 [ 196.277648] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014 [ 196.278634] Call Trace: [ 196.278891] <IRQ> [ 196.279124] dump_stack+0x65/0x8d [ 196.279477] ? kgdb_breakpoint+0x13/0x20 [ 196.279968] kgdb_handle_exception+0x16e/0x1a0 [ 196.280405] __kgdb_notify+0x6d/0xd0 [ 196.280761] kgdb_notify+0x23/0x40 [ 196.281189] notifier_call_chain+0x4a/0x70 [ 196.281589] atomic_notifier_call_chain+0x33/0x50 [ 196.282033] notify_die+0x2e/0x30 [ 196.282469] do_int3+0x70/0x100 [ 196.282792] int3+0x35/0x70 [ 196.283080] RIP: 0010:kgdb_breakpoint+0x14/0x20 [ 196.283596] RSP: 0000:ffff9f2a0fc01d00 EFLAGS: 00000002 [ 196.284078] RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 00000000ffffffff [ 196.284751] RDX: ffffffffa90cd700 RSI: 0000000000000000 RDI: ffffffffa8e4ca10 [ 196.285356] RBP: ffff9f2a0fc01d00 R08: 0000000000000000 R09: ffffffffa8e4ca10 [ 196.286002] R10: ffff9f2a0fc01e00 R11: ffffffffa90d40ed R12: ffffffffa8e4d2e0 [ 196.286614] R13: 0000000000000000 R14: ffffffffa90cd700 R15: 0000000000000000 Signed-off-by: Hongzhi.Song <hongzhi.song(a)windriver.com> --- arch/x86/kernel/traps.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 67db4f4..5a6b8f8 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -209,9 +209,6 @@ do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str, if (fixup_exception(regs, trapnr)) return 0; - if (fixup_bug(regs, trapnr)) - return 0; - tsk->thread.error_code = error_code; tsk->thread.trap_nr = trapnr; die(str, regs, error_code); @@ -292,6 +289,13 @@ static void do_error_trap(struct pt_regs *regs, long error_code, char *str, RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); + /* + * WARN*()s end up here; fix them up before we call the + * notifier chain. + */ + if (!user_mode(regs) && fixup_bug(regs, trapnr)) + return; + if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) != NOTIFY_STOP) { cond_local_irq_enable(regs); -- 2.8.1

7 years, 1 month

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[Linux-stable-mirror] [PATCH] drm/ttm: init locked again to prevent incorrect unlock

by Roger He

Change-Id: Icc8b5112570429f24e90d52484df2728c546f85b Signed-off-by: Roger He <Hongbo.He(a)amd.com> Reviewed-by: Christian König <christian.koenig(a)amd.com> Cc: stable(a)vger.kernel.org --- drivers/gpu/drm/ttm/ttm_bo.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index a3f908c..098b22e 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -735,6 +735,7 @@ static int ttm_mem_evict_first(struct ttm_bo_device *bdev, place)) { if (locked) reservation_object_unlock(bo->resv); + locked = false; continue; } break; -- 2.7.4

7 years, 1 month

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[Linux-stable-mirror] [PATCH] arch/um: compile with modern headers

by Jason A. Donenfeld

Recent libcs have gotten a bit more strict, so we actually need to include the right headers and use the right types. This enables UML to compile again. Signed-off-by: Jason A. Donenfeld <Jason(a)zx2c4.com> Cc: stable(a)vger.kernel.org --- arch/um/os-Linux/file.c | 1 + arch/um/os-Linux/signal.c | 3 ++- arch/x86/um/stub_segv.c | 3 ++- 3 files changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c index 2db18cbbb0ea..c0197097c86e 100644 --- a/arch/um/os-Linux/file.c +++ b/arch/um/os-Linux/file.c @@ -12,6 +12,7 @@ #include <sys/mount.h> #include <sys/socket.h> #include <sys/stat.h> +#include <sys/sysmacros.h> #include <sys/un.h> #include <sys/types.h> #include <os.h> diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c index a86d7cc2c2d8..bf0acb8aad8b 100644 --- a/arch/um/os-Linux/signal.c +++ b/arch/um/os-Linux/signal.c @@ -16,6 +16,7 @@ #include <os.h> #include <sysdep/mcontext.h> #include <um_malloc.h> +#include <sys/ucontext.h> void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = { [SIGTRAP] = relay_signal, @@ -159,7 +160,7 @@ static void (*handlers[_NSIG])(int sig, struct siginfo *si, mcontext_t *mc) = { static void hard_handler(int sig, siginfo_t *si, void *p) { - struct ucontext *uc = p; + ucontext_t *uc = p; mcontext_t *mc = &uc->uc_mcontext; unsigned long pending = 1UL << sig; diff --git a/arch/x86/um/stub_segv.c b/arch/x86/um/stub_segv.c index 1518d2805ae8..27361cbb7ca9 100644 --- a/arch/x86/um/stub_segv.c +++ b/arch/x86/um/stub_segv.c @@ -6,11 +6,12 @@ #include <sysdep/stub.h> #include <sysdep/faultinfo.h> #include <sysdep/mcontext.h> +#include <sys/ucontext.h> void __attribute__ ((__section__ (".__syscall_stub"))) stub_segv_handler(int sig, siginfo_t *info, void *p) { - struct ucontext *uc = p; + ucontext_t *uc = p; GET_FAULTINFO_FROM_MC(*((struct faultinfo *) STUB_DATA), &uc->uc_mcontext); -- 2.15.1

7 years, 1 month

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[Linux-stable-mirror] Fixing CVE-2017-12190 in v4.4.y

by Guenter Roeck

Hi Greg, I am looking into fixing CVE-2017-12190 in chromeos-4.4. The fix requires two patches, 95d78c28b5a85 ("fix unbalanced page refcounting in bio_map_user_iov") and 2b04e8f6bbb1 ("more bio_map_user_iov() leak fixes"). I noticed that the second patch has not been applied to linux-4.4.y. Is that due to the conflict, or was there a conscious decision not to apply it ? On a side note, is there a working archive for stable(a)vger.kernel.org ? The one listed at vger.kernel.org (gmane) doesn't work. Thanks, Guenter

7 years, 1 month

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[Linux-stable-mirror] + acct-fix-the-acct-needcheck-check-in-check_free_space.patch added to -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: kernel/acct.c: fix the acct->needcheck check in check_free_space() has been added to the -mm tree. Its filename is acct-fix-the-acct-needcheck-check-in-check_free_space.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/acct-fix-the-acct-needcheck-check-… and later at http://ozlabs.org/~akpm/mmotm/broken-out/acct-fix-the-acct-needcheck-check-… Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Oleg Nesterov <oleg(a)redhat.com> Subject: kernel/acct.c: fix the acct->needcheck check in check_free_space() As Tsukada explains, the time_is_before_jiffies(acct->needcheck) check is very wrong, we need time_is_after_jiffies() to make sys_acct() work. Ignoring the overflows, the code should "goto out" if needcheck > jiffies, while currently it checks "needcheck < jiffies" and thus in the likely case check_free_space() does nothing until jiffies overflow. In particular this means that sys_acct() is simply broken, acct_on() sets acct->needcheck = jiffies and expects that check_free_space() should set acct->active = 1 after the free-space check, but this won't happen if jiffies increments in between. This was broken by commit 32dc73086015 ("get rid of timer in kern/acct.c") in 2011, then another (correct) commit 795a2f22a8ea ("acct() should honour the limits from the very beginning") made the problem more visible. Link: http://lkml.kernel.org/r/20171213133940.GA6554@redhat.com Fixes: 32dc73086015 ("get rid of timer in kern/acct.c") Reported-by: TSUKADA Koutaro <tsukada(a)ascade.co.jp> Suggested-by: TSUKADA Koutaro <tsukada(a)ascade.co.jp> Signed-off-by: Oleg Nesterov <oleg(a)redhat.com> Cc: Al Viro <viro(a)zeniv.linux.org.uk> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- kernel/acct.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN kernel/acct.c~acct-fix-the-acct-needcheck-check-in-check_free_space kernel/acct.c --- a/kernel/acct.c~acct-fix-the-acct-needcheck-check-in-check_free_space +++ a/kernel/acct.c @@ -102,7 +102,7 @@ static int check_free_space(struct bsd_a { struct kstatfs sbuf; - if (time_is_before_jiffies(acct->needcheck)) + if (time_is_after_jiffies(acct->needcheck)) goto out; /* May block */ _ Patches currently in -mm which might be from oleg(a)redhat.com are acct-fix-the-acct-needcheck-check-in-check_free_space.patch

7 years, 1 month

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[Linux-stable-mirror] [PATCH] dm: Fix a recently introduced reference counting bug

by Bart Van Assche

This patch avoids that the following message occurs sporadically in the system log (revealing that pgpath->path.dev->name became a dangling pointer): device-mapper: table: 254:2: device kkkkkkkkkkkkkkkkkkk?????????x0?a?????E??????????????E??????F?????2?????pF??????PF?????9[F??????]F???????#???????#??????'f????? not in table devices list This patch also fixes the following kernel crash: general protection fault: 0000 [#1] PREEMPT SMP RIP: 0010:multipath_busy+0x77/0xd0 [dm_multipath] Call Trace: dm_mq_queue_rq+0x44/0x110 [dm_mod] blk_mq_dispatch_rq_list+0x73/0x440 blk_mq_do_dispatch_sched+0x60/0xe0 blk_mq_sched_dispatch_requests+0x11a/0x1a0 __blk_mq_run_hw_queue+0x11f/0x1c0 __blk_mq_delay_run_hw_queue+0x95/0xe0 blk_mq_run_hw_queue+0x25/0x80 blk_mq_flush_plug_list+0x197/0x420 blk_flush_plug_list+0xe4/0x270 blk_finish_plug+0x27/0x40 __do_page_cache_readahead+0x2b4/0x370 force_page_cache_readahead+0xb4/0x110 generic_file_read_iter+0x755/0x970 __vfs_read+0xd2/0x140 vfs_read+0x9b/0x140 SyS_read+0x45/0xa0 do_syscall_64+0x56/0x1a0 entry_SYSCALL64_slow_path+0x25/0x25 >From the disassembly of multipath_busy (0x77 = 119): ./include/linux/blkdev.h: 992 return bdev->bd_disk->queue; /* this is never NULL */ 0x00000000000006b4 <+116>: mov (%rax),%rax 0x00000000000006b7 <+119>: mov 0xe0(%rax),%rax Fixes: commit 2a0b4682e09d ("dm: convert dm_dev_internal.count from atomic_t to refcount_t") Signed-off-by: Bart Van Assche <bart.vanassche(a)wdc.com> Cc: Elena Reshetova <elena.reshetova(a)intel.com> Cc: Kees Cook <keescook(a)chromium.org> Cc: David Windsor <dwindsor(a)gmail.com> Cc: Hans Liljestrand <ishkamiel(a)gmail.com> Cc: Hannes Reinecke <hare(a)suse.com> Cc: stable(a)vger.kernel.org # v4.15 --- drivers/md/dm-table.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 88130b5d95f9..ee5c389e7256 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -459,6 +459,8 @@ int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode, if (r) return r; refcount_inc(&dd->count); + } else { + refcount_inc(&dd->count); } *result = dd->dm_dev; -- 2.15.1

7 years, 1 month

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[Linux-stable-mirror] [PATCH] drm: rework delayed connector cleanup in connector_iter

by Daniel Vetter

PROBE_DEFER also uses system_wq to reprobe drivers, which means when that again fails, and we try to flush the overall system_wq (to get all the delayed connectore cleanup work_struct completed), we deadlock. Fix this by using just a single cleanup work, so that we can only flush that one and don't block on anything else. That means a free list plus locking, a standard pattern. Fixes: a703c55004e1 ("drm: safely free connectors from connector_iter") Fixes: 613051dac40d ("drm: locking&new iterators for connector_list") Cc: Ben Widawsky <ben(a)bwidawsk.net> Cc: Dave Airlie <airlied(a)gmail.com> Cc: Chris Wilson <chris(a)chris-wilson.co.uk> Cc: Sean Paul <seanpaul(a)chromium.org> Cc: <stable(a)vger.kernel.org> # v4.11+: 613051dac40d ("drm: locking&new iterators for connector_list" Cc: <stable(a)vger.kernel.org> # v4.11+ Cc: Daniel Vetter <daniel.vetter(a)intel.com> Cc: Jani Nikula <jani.nikula(a)linux.intel.com> Cc: Gustavo Padovan <gustavo(a)padovan.org> Cc: David Airlie <airlied(a)linux.ie> Cc: Javier Martinez Canillas <javier(a)dowhile0.org> Cc: Shuah Khan <shuahkh(a)osg.samsung.com> Cc: Guillaume Tucker <guillaume.tucker(a)collabora.com> Cc: Mark Brown <broonie(a)kernel.org> Cc: Kevin Hilman <khilman(a)baylibre.com> Cc: Matt Hart <matthew.hart(a)linaro.org> Cc: Thierry Escande <thierry.escande(a)collabora.co.uk> Cc: Tomeu Vizoso <tomeu.vizoso(a)collabora.com> Cc: Enric Balletbo i Serra <enric.balletbo(a)collabora.com> Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> --- drivers/gpu/drm/drm_connector.c | 46 ++++++++++++++++++++++++++----------- drivers/gpu/drm/drm_crtc_internal.h | 1 + drivers/gpu/drm/drm_mode_config.c | 5 +++- include/drm/drm_connector.h | 4 ++-- include/drm/drm_mode_config.h | 17 +++++++++++++- 5 files changed, 55 insertions(+), 18 deletions(-) diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c index 0b7e0974e6da..2f43dc217936 100644 --- a/drivers/gpu/drm/drm_connector.c +++ b/drivers/gpu/drm/drm_connector.c @@ -153,14 +153,23 @@ static void drm_connector_free(struct kref *kref) connector->funcs->destroy(connector); } -static void drm_connector_free_work_fn(struct work_struct *work) +void drm_connector_free_work_fn(struct work_struct *work) { - struct drm_connector *connector = - container_of(work, struct drm_connector, free_work); - struct drm_device *dev = connector->dev; + struct drm_connector *connector; + struct drm_device *dev = + container_of(work, struct drm_device, mode_config.connector_free_work); + struct drm_mode_config *config = &dev->mode_config; + unsigned long flags; + LIST_HEAD(list_head); - drm_mode_object_unregister(dev, &connector->base); - connector->funcs->destroy(connector); + spin_lock_irqsave(&config->connector_list_lock, flags); + list_splice(&config->connector_free_list, &list_head); + spin_unlock_irqrestore(&config->connector_list_lock, flags); + + list_for_each_entry(connector, &list_head, free_head) { + drm_mode_object_unregister(dev, &connector->base); + connector->funcs->destroy(connector); + } } /** @@ -192,8 +201,6 @@ int drm_connector_init(struct drm_device *dev, if (ret) return ret; - INIT_WORK(&connector->free_work, drm_connector_free_work_fn); - connector->base.properties = &connector->properties; connector->dev = dev; connector->funcs = funcs; @@ -550,10 +557,15 @@ EXPORT_SYMBOL(drm_connector_list_iter_begin); * actually release the connector when dropping our final reference. */ static void -drm_connector_put_safe(struct drm_connector *conn) +__drm_connector_put_safe(struct drm_connector *conn) { + struct drm_mode_config *config = &conn->dev->mode_config; + + lockdep_assert_held(&config->connector_list_lock); + list_add(&conn->free_head, &config->connector_free_list); + if (refcount_dec_and_test(&conn->base.refcount.refcount)) - schedule_work(&conn->free_work); + schedule_work(&config->connector_free_work); } /** @@ -585,10 +597,10 @@ drm_connector_list_iter_next(struct drm_connector_list_iter *iter) /* loop until it's not a zombie connector */ } while (!kref_get_unless_zero(&iter->conn->base.refcount)); - spin_unlock_irqrestore(&config->connector_list_lock, flags); if (old_conn) - drm_connector_put_safe(old_conn); + __drm_connector_put_safe(old_conn); + spin_unlock_irqrestore(&config->connector_list_lock, flags); return iter->conn; } @@ -605,9 +617,15 @@ EXPORT_SYMBOL(drm_connector_list_iter_next); */ void drm_connector_list_iter_end(struct drm_connector_list_iter *iter) { + struct drm_mode_config *config = &iter->dev->mode_config; + unsigned long flags; + iter->dev = NULL; - if (iter->conn) - drm_connector_put_safe(iter->conn); + if (iter->conn) { + spin_lock_irqsave(&config->connector_list_lock, flags); + __drm_connector_put_safe(iter->conn); + spin_unlock_irqrestore(&config->connector_list_lock, flags); + } lock_release(&connector_list_iter_dep_map, 0, _RET_IP_); } EXPORT_SYMBOL(drm_connector_list_iter_end); diff --git a/drivers/gpu/drm/drm_crtc_internal.h b/drivers/gpu/drm/drm_crtc_internal.h index 9ebb8841778c..af00f42ba269 100644 --- a/drivers/gpu/drm/drm_crtc_internal.h +++ b/drivers/gpu/drm/drm_crtc_internal.h @@ -142,6 +142,7 @@ int drm_mode_connector_set_obj_prop(struct drm_mode_object *obj, uint64_t value); int drm_connector_create_standard_properties(struct drm_device *dev); const char *drm_get_connector_force_name(enum drm_connector_force force); +void drm_connector_free_work_fn(struct work_struct *work); /* IOCTL */ int drm_mode_connector_property_set_ioctl(struct drm_device *dev, diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c index 6ffe952142e6..025fc23cf7c6 100644 --- a/drivers/gpu/drm/drm_mode_config.c +++ b/drivers/gpu/drm/drm_mode_config.c @@ -373,6 +373,7 @@ void drm_mode_config_init(struct drm_device *dev) INIT_LIST_HEAD(&dev->mode_config.fb_list); INIT_LIST_HEAD(&dev->mode_config.crtc_list); INIT_LIST_HEAD(&dev->mode_config.connector_list); + INIT_LIST_HEAD(&dev->mode_config.connector_free_list); INIT_LIST_HEAD(&dev->mode_config.encoder_list); INIT_LIST_HEAD(&dev->mode_config.property_list); INIT_LIST_HEAD(&dev->mode_config.property_blob_list); @@ -382,6 +383,8 @@ void drm_mode_config_init(struct drm_device *dev) ida_init(&dev->mode_config.connector_ida); spin_lock_init(&dev->mode_config.connector_list_lock); + INIT_WORK(&dev->mode_config.connector_free_work, drm_connector_free_work_fn); + drm_mode_create_standard_properties(dev); /* Just to be sure */ @@ -432,7 +435,7 @@ void drm_mode_config_cleanup(struct drm_device *dev) } drm_connector_list_iter_end(&conn_iter); /* connector_iter drops references in a work item. */ - flush_scheduled_work(); + flush_work(&dev->mode_config.connector_free_work); if (WARN_ON(!list_empty(&dev->mode_config.connector_list))) { drm_connector_list_iter_begin(dev, &conn_iter); drm_for_each_connector_iter(connector, &conn_iter) diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h index ee3155391243..50bc21050fbf 100644 --- a/include/drm/drm_connector.h +++ b/include/drm/drm_connector.h @@ -966,12 +966,12 @@ struct drm_connector { uint16_t tile_h_size, tile_v_size; /** - * @free_work: + * @free_head: * * Work used only by &drm_connector_iter to be able to clean up a * connector from any context. */ - struct work_struct free_work; + struct list_head free_head; }; #define obj_to_connector(x) container_of(x, struct drm_connector, base) diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h index e5f3b43014e1..5e62e52a2c58 100644 --- a/include/drm/drm_mode_config.h +++ b/include/drm/drm_mode_config.h @@ -402,7 +402,7 @@ struct drm_mode_config { /** * @connector_list_lock: Protects @num_connector and - * @connector_list. + * @connector_list and @connector_free_list. */ spinlock_t connector_list_lock; /** @@ -422,6 +422,21 @@ struct drm_mode_config { * &struct drm_connector_list_iter to walk this list. */ struct list_head connector_list; + /** + * @connector_free_list: + * + * List of connector objects linked with &drm_connector.free_head. + * Protected by @connector_list_lock. Used by + * drm_for_each_connector_iter() and + * &struct drm_connector_list_iter to savely free connectors using + * @connector_free_work. + */ + struct list_head connector_free_list; + /** + * @connector_free_work: Work to clean up @connector_free_list. + */ + struct work_struct connector_free_work; + /** * @num_encoder: * -- 2.15.1

7 years, 1 month

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[Linux-stable-mirror] [for-next][PATCH 3/7] tracing: Allocate mask_str buffer dynamically

by Steven Rostedt

From: Changbin Du <changbin.du(a)intel.com> The default NR_CPUS can be very large, but actual possible nr_cpu_ids usually is very small. For my x86 distribution, the NR_CPUS is 8192 and nr_cpu_ids is 4. About 2 pages are wasted. Most machines don't have so many CPUs, so define a array with NR_CPUS just wastes memory. So let's allocate the buffer dynamically when need. With this change, the mutext tracing_cpumask_update_lock also can be removed now, which was used to protect mask_str. Link: http://lkml.kernel.org/r/1512013183-19107-1-git-send-email-changbin.du@inte… Fixes: 36dfe9252bd4c ("ftrace: make use of tracing_cpumask") Cc: stable(a)vger.kernel.org Signed-off-by: Changbin Du <changbin.du(a)intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org> --- kernel/trace/trace.c | 29 +++++++++-------------------- 1 file changed, 9 insertions(+), 20 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 5815ec16edd4..9f3f043ba3b7 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4178,37 +4178,30 @@ static const struct file_operations show_traces_fops = { .llseek = seq_lseek, }; -/* - * The tracer itself will not take this lock, but still we want - * to provide a consistent cpumask to user-space: - */ -static DEFINE_MUTEX(tracing_cpumask_update_lock); - -/* - * Temporary storage for the character representation of the - * CPU bitmask (and one more byte for the newline): - */ -static char mask_str[NR_CPUS + 1]; - static ssize_t tracing_cpumask_read(struct file *filp, char __user *ubuf, size_t count, loff_t *ppos) { struct trace_array *tr = file_inode(filp)->i_private; + char *mask_str; int len; - mutex_lock(&tracing_cpumask_update_lock); + len = snprintf(NULL, 0, "%*pb\n", + cpumask_pr_args(tr->tracing_cpumask)) + 1; + mask_str = kmalloc(len, GFP_KERNEL); + if (!mask_str) + return -ENOMEM; - len = snprintf(mask_str, count, "%*pb\n", + len = snprintf(mask_str, len, "%*pb\n", cpumask_pr_args(tr->tracing_cpumask)); if (len >= count) { count = -EINVAL; goto out_err; } - count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1); + count = simple_read_from_buffer(ubuf, count, ppos, mask_str, len); out_err: - mutex_unlock(&tracing_cpumask_update_lock); + kfree(mask_str); return count; } @@ -4228,8 +4221,6 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, if (err) goto err_unlock; - mutex_lock(&tracing_cpumask_update_lock); - local_irq_disable(); arch_spin_lock(&tr->max_lock); for_each_tracing_cpu(cpu) { @@ -4252,8 +4243,6 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, local_irq_enable(); cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new); - - mutex_unlock(&tracing_cpumask_update_lock); free_cpumask_var(tracing_cpumask_new); return count; -- 2.13.2

7 years, 1 month

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[Linux-stable-mirror] TSC x86 fixes for LTS kernel 4.9.x

by Dan Aloni

Hi all, I've tested the following changes, belonging to merge commit f7dd3b1734e, on top of 4.9.68 after a very easy backport from 4.10, and I think it may be worthwhile adding them to 4.9.x: x86/tsc: Limit the adjust value further x86/tsc: Annotate printouts as firmware bug x86/tsc: Force TSC_ADJUST register to value >= zero x86/tsc: Validate TSC_ADJUST after resume x86/tsc: Validate cpumask pointer before accessing it x86/tsc: Fix broken CONFIG_X86_TSC=n build x86/tsc: Try to adjust TSC if sync test fails x86/tsc: Prepare warp test for TSC adjustment x86/tsc: Move sync cleanup to a safe place x86/tsc: Sync test only for the first cpu in a package x86/tsc: Verify TSC_ADJUST from idle x86/tsc: Store and check TSC ADJUST MSR x86/tsc: Detect random warps x86/tsc: Use X86_FEATURE_TSC_ADJUST in detect_art() x86/tsc: Finalize the split of the TSC_RELIABLE flag x86/tsc: Set TSC_KNOWN_FREQ and TSC_RELIABLE flags on Intel Atom SoCs x86/tsc: Mark Intel ATOM_GOLDMONT TSC reliable x86/tsc: Mark TSC frequency determined by CPUID as known x86/tsc: Add X86_FEATURE_TSC_KNOWN_FREQ flag These changes percisely fix an issue I am having with a relatively new 8-core Intel(R) Core(TM) i7-7820X with an updated ASUS BIOS (December 2017). Under v4.9.68, the kernel fallbacks on the chosen clocksource to HPET which just doesn't work - there is over a 200ms time drift that does not go away even after repeated ntpdate sync attempts. For further testing I've posted a branch for these changes here: https://github.com/kernelim/linux tsc-fix-for-4.9.x -- Dan Aloni

7 years, 1 month

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[Linux-stable-mirror] patch "staging: ion: Fix ion_cma_heap allocations" added to staging-linus

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled staging: ion: Fix ion_cma_heap allocations to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From d98e6dbf42f73101128885a1e0ae672cd92b2e1a Mon Sep 17 00:00:00 2001 From: John Stultz <john.stultz(a)linaro.org> Date: Fri, 8 Dec 2017 17:11:12 -0800 Subject: staging: ion: Fix ion_cma_heap allocations In trying to add support for drm_hwcomposer to HiKey, I've needed to utilize the ION CMA heap, and I've noticed problems with allocations on newer kernels failing. It seems back with 204f672255c2 ("ion: Use CMA APIs directly"), the ion_cma_heap code was modified to use the CMA API, but kept the arguments as buffer lengths rather then number of pages. This results in errors as we don't have enough pages in CMA to satisfy the exaggerated requests. This patch converts the ion_cma_heap CMA API usage to properly request pages. It also fixes a minor issue in the allocation where in the error path, the cma_release is called with the buffer->size value which hasn't yet been set. Cc: Laura Abbott <labbott(a)redhat.com> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Benjamin Gaignard <benjamin.gaignard(a)linaro.org> Cc: Archit Taneja <architt(a)codeaurora.org> Cc: Daniel Vetter <daniel(a)ffwll.ch> Cc: Dmitry Shmidt <dimitrysh(a)google.com> Cc: Todd Kjos <tkjos(a)google.com> Cc: Amit Pundir <amit.pundir(a)linaro.org> Fixes: 204f672255c2 ("staging: android: ion: Use CMA APIs directly") Cc: stable <stable(a)vger.kernel.org> Acked-by: Laura Abbott <labbott(a)redhat.com> Signed-off-by: John Stultz <john.stultz(a)linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/staging/android/ion/ion_cma_heap.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/staging/android/ion/ion_cma_heap.c b/drivers/staging/android/ion/ion_cma_heap.c index dd5545d9990a..86196ffd2faf 100644 --- a/drivers/staging/android/ion/ion_cma_heap.c +++ b/drivers/staging/android/ion/ion_cma_heap.c @@ -39,9 +39,15 @@ static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer, struct ion_cma_heap *cma_heap = to_cma_heap(heap); struct sg_table *table; struct page *pages; + unsigned long size = PAGE_ALIGN(len); + unsigned long nr_pages = size >> PAGE_SHIFT; + unsigned long align = get_order(size); int ret; - pages = cma_alloc(cma_heap->cma, len, 0, GFP_KERNEL); + if (align > CONFIG_CMA_ALIGNMENT) + align = CONFIG_CMA_ALIGNMENT; + + pages = cma_alloc(cma_heap->cma, nr_pages, align, GFP_KERNEL); if (!pages) return -ENOMEM; @@ -53,7 +59,7 @@ static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer, if (ret) goto free_mem; - sg_set_page(table->sgl, pages, len, 0); + sg_set_page(table->sgl, pages, size, 0); buffer->priv_virt = pages; buffer->sg_table = table; @@ -62,7 +68,7 @@ static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer, free_mem: kfree(table); err: - cma_release(cma_heap->cma, pages, buffer->size); + cma_release(cma_heap->cma, pages, nr_pages); return -ENOMEM; } @@ -70,9 +76,10 @@ static void ion_cma_free(struct ion_buffer *buffer) { struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap); struct page *pages = buffer->priv_virt; + unsigned long nr_pages = PAGE_ALIGN(buffer->size) >> PAGE_SHIFT; /* release memory */ - cma_release(cma_heap->cma, pages, buffer->size); + cma_release(cma_heap->cma, pages, nr_pages); /* release sg table */ sg_free_table(buffer->sg_table); kfree(buffer->sg_table); -- 2.15.1

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Linux-stable-mirror December 2017