From f71996c3ce5d3b7ee0f581f6c2c37a19d50d72e8 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Fri, 14 Oct 2016 11:23:09 +0200 Subject: [PATCH 01/13] p54: memset(0) whole array commit 6f17581788206444cbbcdbc107498f85e9765e3d upstream. gcc 7 complains: drivers/net/wireless/intersil/p54/fwio.c: In function 'p54_scan': drivers/net/wireless/intersil/p54/fwio.c:491:4: warning: 'memset' used with length equal to number of elements without multiplication by element size [-Wmemset-elt-size] Fix that by passing the correct size to memset. Signed-off-by: Jiri Slaby Cc: Christian Lamparter Cc: Kalle Valo Acked-by: Christian Lamparter Signed-off-by: Kalle Valo Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/intersil/p54/fwio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wireless/intersil/p54/fwio.c b/drivers/net/wireless/intersil/p54/fwio.c index 257a9eadd595..4ac6764f4897 100644 --- a/drivers/net/wireless/intersil/p54/fwio.c +++ b/drivers/net/wireless/intersil/p54/fwio.c @@ -488,7 +488,7 @@ int p54_scan(struct p54_common *priv, u16 mode, u16 dwell) entry += sizeof(__le16); chan->pa_points_per_curve = 8; - memset(chan->curve_data, 0, sizeof(*chan->curve_data)); + memset(chan->curve_data, 0, sizeof(chan->curve_data)); memcpy(chan->curve_data, entry, sizeof(struct p54_pa_curve_data_sample) * min((u8)8, curve_data->points_per_channel)); From dd758f82a3bf2f11843a59188cd0d7922dbcc731 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 18 Nov 2016 17:14:01 +0100 Subject: [PATCH 02/13] scsi: isci: avoid array subscript warning commit 5cfa2a3c7342bd0b50716c8bb32ee491af43c785 upstream. I'm getting a new warning with gcc-7: isci/remote_node_context.c: In function 'sci_remote_node_context_destruct': isci/remote_node_context.c:69:16: error: array subscript is above array bounds [-Werror=array-bounds] This is odd, since we clearly cover all values for enum scis_sds_remote_node_context_states here. Anyway, checking for an array overflow can't harm and it makes the warning go away. Signed-off-by: Arnd Bergmann Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/isci/remote_node_context.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/scsi/isci/remote_node_context.c b/drivers/scsi/isci/remote_node_context.c index 1910100638a2..00602abec0ea 100644 --- a/drivers/scsi/isci/remote_node_context.c +++ b/drivers/scsi/isci/remote_node_context.c @@ -66,6 +66,9 @@ const char *rnc_state_name(enum scis_sds_remote_node_context_states state) { static const char * const strings[] = RNC_STATES; + if (state >= ARRAY_SIZE(strings)) + return "UNKNOWN"; + return strings[state]; } #undef C From 47974403c9caadc9fdb762e399569689efb02386 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 16 Nov 2016 16:07:10 +0100 Subject: [PATCH 03/13] staging: wilc1000: simplify vif[i]->ndev accesses commit 735bb39ca3bed8469b3b3a42d8cc57bdb9fc4dd7 upstream. With gcc-7, I got a new warning for this driver: wilc1000/linux_wlan.c: In function 'wilc_netdev_cleanup': wilc1000/linux_wlan.c:1224:15: error: 'vif[1]' may be used uninitialized in this function [-Werror=maybe-uninitialized] wilc1000/linux_wlan.c:1224:15: error: 'vif[0]' may be used uninitialized in this function [-Werror=maybe-uninitialized] A closer look at the function reveals that it's more complex than it needs to be, given that based on how the device is created we always get netdev_priv(vif->ndev) == vif Based on this assumption, I found a few other places in the same file that can be simplified. That code appears to be a relic from times when the assumption above was not valid. Signed-off-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman --- drivers/staging/wilc1000/linux_wlan.c | 34 +++++++-------------------- 1 file changed, 9 insertions(+), 25 deletions(-) diff --git a/drivers/staging/wilc1000/linux_wlan.c b/drivers/staging/wilc1000/linux_wlan.c index 6370a5efe343..defffa75ae1c 100644 --- a/drivers/staging/wilc1000/linux_wlan.c +++ b/drivers/staging/wilc1000/linux_wlan.c @@ -269,23 +269,12 @@ static struct net_device *get_if_handler(struct wilc *wilc, u8 *mac_header) int wilc_wlan_set_bssid(struct net_device *wilc_netdev, u8 *bssid, u8 mode) { - int i = 0; - int ret = -1; - struct wilc_vif *vif; - struct wilc *wilc; + struct wilc_vif *vif = netdev_priv(wilc_netdev); - vif = netdev_priv(wilc_netdev); - wilc = vif->wilc; + memcpy(vif->bssid, bssid, 6); + vif->mode = mode; - for (i = 0; i < wilc->vif_num; i++) - if (wilc->vif[i]->ndev == wilc_netdev) { - memcpy(wilc->vif[i]->bssid, bssid, 6); - wilc->vif[i]->mode = mode; - ret = 0; - break; - } - - return ret; + return 0; } int wilc_wlan_get_num_conn_ifcs(struct wilc *wilc) @@ -1212,16 +1201,11 @@ void WILC_WFI_mgmt_rx(struct wilc *wilc, u8 *buff, u32 size) void wilc_netdev_cleanup(struct wilc *wilc) { - int i = 0; - struct wilc_vif *vif[NUM_CONCURRENT_IFC]; + int i; - if (wilc && (wilc->vif[0]->ndev || wilc->vif[1]->ndev)) { + if (wilc && (wilc->vif[0]->ndev || wilc->vif[1]->ndev)) unregister_inetaddr_notifier(&g_dev_notifier); - for (i = 0; i < NUM_CONCURRENT_IFC; i++) - vif[i] = netdev_priv(wilc->vif[i]->ndev); - } - if (wilc && wilc->firmware) { release_firmware(wilc->firmware); wilc->firmware = NULL; @@ -1230,7 +1214,7 @@ void wilc_netdev_cleanup(struct wilc *wilc) if (wilc && (wilc->vif[0]->ndev || wilc->vif[1]->ndev)) { for (i = 0; i < NUM_CONCURRENT_IFC; i++) if (wilc->vif[i]->ndev) - if (vif[i]->mac_opened) + if (wilc->vif[i]->mac_opened) wilc_mac_close(wilc->vif[i]->ndev); for (i = 0; i < NUM_CONCURRENT_IFC; i++) { @@ -1278,9 +1262,9 @@ int wilc_netdev_init(struct wilc **wilc, struct device *dev, int io_type, vif->idx = wl->vif_num; vif->wilc = *wilc; + vif->ndev = ndev; wl->vif[i] = vif; - wl->vif[wl->vif_num]->ndev = ndev; - wl->vif_num++; + wl->vif_num = i; ndev->netdev_ops = &wilc_netdev_ops; { From b8a1532b16fd49596304e1cfd285cf4509b6fba7 Mon Sep 17 00:00:00 2001 From: Martin Liska Date: Fri, 12 May 2017 15:46:35 -0700 Subject: [PATCH 04/13] gcov: support GCC 7.1 commit 05384213436ab690c46d9dfec706b80ef8d671ab upstream. Starting from GCC 7.1, __gcov_exit is a new symbol expected to be implemented in a profiling runtime. [akpm@linux-foundation.org: coding-style fixes] [mliska@suse.cz: v2] Link: http://lkml.kernel.org/r/e63a3c59-0149-c97e-4084-20ca8f146b26@suse.cz Link: http://lkml.kernel.org/r/8c4084fa-3885-29fe-5fc4-0d4ca199c785@suse.cz Signed-off-by: Martin Liska Acked-by: Peter Oberparleiter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- kernel/gcov/base.c | 6 ++++++ kernel/gcov/gcc_4_7.c | 4 +++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/kernel/gcov/base.c b/kernel/gcov/base.c index 2f9df37940a0..c51a49c9be70 100644 --- a/kernel/gcov/base.c +++ b/kernel/gcov/base.c @@ -98,6 +98,12 @@ void __gcov_merge_icall_topn(gcov_type *counters, unsigned int n_counters) } EXPORT_SYMBOL(__gcov_merge_icall_topn); +void __gcov_exit(void) +{ + /* Unused. */ +} +EXPORT_SYMBOL(__gcov_exit); + /** * gcov_enable_events - enable event reporting through gcov_event() * diff --git a/kernel/gcov/gcc_4_7.c b/kernel/gcov/gcc_4_7.c index 6a5c239c7669..46a18e72bce6 100644 --- a/kernel/gcov/gcc_4_7.c +++ b/kernel/gcov/gcc_4_7.c @@ -18,7 +18,9 @@ #include #include "gcov.h" -#if (__GNUC__ > 5) || (__GNUC__ == 5 && __GNUC_MINOR__ >= 1) +#if (__GNUC__ >= 7) +#define GCOV_COUNTERS 9 +#elif (__GNUC__ > 5) || (__GNUC__ == 5 && __GNUC_MINOR__ >= 1) #define GCOV_COUNTERS 10 #elif __GNUC__ == 4 && __GNUC_MINOR__ >= 9 #define GCOV_COUNTERS 9 From 3e033635b2b7eab01855c5a3e426e364064fd12b Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Wed, 3 May 2017 15:17:51 +0100 Subject: [PATCH 05/13] kvm: arm/arm64: Fix race in resetting stage2 PGD MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 6c0d706b563af732adb094c5bf807437e8963e84 upstream. In kvm_free_stage2_pgd() we check the stage2 PGD before holding the lock and proceed to take the lock if it is valid. And we unmap the page tables, followed by releasing the lock. We reset the PGD only after dropping this lock, which could cause a race condition where another thread waiting on or even holding the lock, could potentially see that the PGD is still valid and proceed to perform a stage2 operation and later encounter a NULL PGD. [223090.242280] Unable to handle kernel NULL pointer dereference at virtual address 00000040 [223090.262330] PC is at unmap_stage2_range+0x8c/0x428 [223090.262332] LR is at kvm_unmap_hva_handler+0x2c/0x3c [223090.262531] Call trace: [223090.262533] [] unmap_stage2_range+0x8c/0x428 [223090.262535] [] kvm_unmap_hva_handler+0x2c/0x3c [223090.262537] [] handle_hva_to_gpa+0xb0/0x104 [223090.262539] [] kvm_unmap_hva+0x5c/0xbc [223090.262543] [] kvm_mmu_notifier_invalidate_page+0x50/0x8c [223090.262547] [] __mmu_notifier_invalidate_page+0x5c/0x84 [223090.262551] [] try_to_unmap_one+0x1d0/0x4a0 [223090.262553] [] rmap_walk+0x1cc/0x2e0 [223090.262555] [] try_to_unmap+0x74/0xa4 [223090.262557] [] migrate_pages+0x31c/0x5ac [223090.262561] [] compact_zone+0x3fc/0x7ac [223090.262563] [] compact_zone_order+0x94/0xb0 [223090.262564] [] try_to_compact_pages+0x108/0x290 [223090.262569] [] __alloc_pages_direct_compact+0x70/0x1ac [223090.262571] [] __alloc_pages_nodemask+0x434/0x9f4 [223090.262572] [] alloc_pages_vma+0x230/0x254 [223090.262574] [] do_huge_pmd_anonymous_page+0x114/0x538 [223090.262576] [] handle_mm_fault+0xd40/0x17a4 [223090.262577] [] __get_user_pages+0x12c/0x36c [223090.262578] [] get_user_pages_unlocked+0xa4/0x1b8 [223090.262579] [] __gfn_to_pfn_memslot+0x280/0x31c [223090.262580] [] gfn_to_pfn_prot+0x4c/0x5c [223090.262582] [] kvm_handle_guest_abort+0x240/0x774 [223090.262584] [] handle_exit+0x11c/0x1ac [223090.262586] [] kvm_arch_vcpu_ioctl_run+0x31c/0x648 [223090.262587] [] kvm_vcpu_ioctl+0x378/0x768 [223090.262590] [] do_vfs_ioctl+0x324/0x5a4 [223090.262591] [] SyS_ioctl+0x90/0xa4 [223090.262595] [] el0_svc_naked+0x38/0x3c This patch moves the stage2 PGD manipulation under the lock. Reported-by: Alexander Graf Cc: Mark Rutland Cc: Marc Zyngier Cc: Paolo Bonzini Cc: Radim Krčmář Reviewed-by: Christoffer Dall Reviewed-by: Marc Zyngier Signed-off-by: Suzuki K Poulose Signed-off-by: Christoffer Dall Signed-off-by: Greg Kroah-Hartman --- arch/arm/kvm/mmu.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 710511cadd50..0c060c5e844a 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -829,22 +829,22 @@ void stage2_unmap_vm(struct kvm *kvm) * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all * underlying level-2 and level-3 tables before freeing the actual level-1 table * and setting the struct pointer to NULL. - * - * Note we don't need locking here as this is only called when the VM is - * destroyed, which can only be done once. */ void kvm_free_stage2_pgd(struct kvm *kvm) { - if (kvm->arch.pgd == NULL) - return; + void *pgd = NULL; spin_lock(&kvm->mmu_lock); - unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE); + if (kvm->arch.pgd) { + unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE); + pgd = kvm->arch.pgd; + kvm->arch.pgd = NULL; + } spin_unlock(&kvm->mmu_lock); /* Free the HW pgd, one page at a time */ - free_pages_exact(kvm->arch.pgd, S2_PGD_SIZE); - kvm->arch.pgd = NULL; + if (pgd) + free_pages_exact(pgd, S2_PGD_SIZE); } static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, From 509d8b52bbe7e6f6022a086989e7ecf5180508cc Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Tue, 11 Jul 2017 15:19:22 +0100 Subject: [PATCH 06/13] arm64: mm: abort uaccess retries upon fatal signal commit 289d07a2dc6c6b6f3e4b8a62669320d99dbe6c3d upstream. When there's a fatal signal pending, arm64's do_page_fault() implementation returns 0. The intent is that we'll return to the faulting userspace instruction, delivering the signal on the way. However, if we take a fatal signal during fixing up a uaccess, this results in a return to the faulting kernel instruction, which will be instantly retried, resulting in the same fault being taken forever. As the task never reaches userspace, the signal is not delivered, and the task is left unkillable. While the task is stuck in this state, it can inhibit the forward progress of the system. To avoid this, we must ensure that when a fatal signal is pending, we apply any necessary fixup for a faulting kernel instruction. Thus we will return to an error path, and it is up to that code to make forward progress towards delivering the fatal signal. Cc: Catalin Marinas Cc: Laura Abbott Reviewed-by: Steve Capper Tested-by: Steve Capper Reviewed-by: James Morse Tested-by: James Morse Signed-off-by: Mark Rutland Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- arch/arm64/mm/fault.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 0e90c7e0279c..fec5b1ce97f8 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -373,8 +373,11 @@ retry: * signal first. We do not need to release the mmap_sem because it * would already be released in __lock_page_or_retry in mm/filemap.c. */ - if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) + if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) { + if (!user_mode(regs)) + goto no_context; return 0; + } /* * Major/minor page fault accounting is only done on the initial From 43f776dab360931f3dd344c8f4fb28b52ea98ee9 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 19 Jul 2017 14:53:02 +0200 Subject: [PATCH 07/13] x86/io: Add "memory" clobber to insb/insw/insl/outsb/outsw/outsl MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 7206f9bf108eb9513d170c73f151367a1bdf3dbf upstream. The x86 version of insb/insw/insl uses an inline assembly that does not have the target buffer listed as an output. This can confuse the compiler, leading it to think that a subsequent access of the buffer is uninitialized: drivers/net/wireless/wl3501_cs.c: In function ‘wl3501_mgmt_scan_confirm’: drivers/net/wireless/wl3501_cs.c:665:9: error: ‘sig.status’ is used uninitialized in this function [-Werror=uninitialized] drivers/net/wireless/wl3501_cs.c:668:12: error: ‘sig.cap_info’ may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/net/sb1000.c: In function 'sb1000_rx': drivers/net/sb1000.c:775:9: error: 'st[0]' is used uninitialized in this function [-Werror=uninitialized] drivers/net/sb1000.c:776:10: error: 'st[1]' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/net/sb1000.c:784:11: error: 'st[1]' may be used uninitialized in this function [-Werror=maybe-uninitialized] I tried to mark the exact input buffer as an output here, but couldn't figure it out. As suggested by Linus, marking all memory as clobbered however is good enough too. For the outs operations, I also add the memory clobber, to force the input to be written to local variables. This is probably already guaranteed by the "asm volatile", but it can't hurt to do this for symmetry. Suggested-by: Linus Torvalds Signed-off-by: Arnd Bergmann Acked-by: Linus Torvalds Cc: Borislav Petkov Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tom Lendacky Link: http://lkml.kernel.org/r/20170719125310.2487451-5-arnd@arndb.de Link: https://lkml.org/lkml/2017/7/12/605 Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/io.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index d34bd370074b..6c5020163db0 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -304,13 +304,13 @@ static inline unsigned type in##bwl##_p(int port) \ static inline void outs##bwl(int port, const void *addr, unsigned long count) \ { \ asm volatile("rep; outs" #bwl \ - : "+S"(addr), "+c"(count) : "d"(port)); \ + : "+S"(addr), "+c"(count) : "d"(port) : "memory"); \ } \ \ static inline void ins##bwl(int port, void *addr, unsigned long count) \ { \ asm volatile("rep; ins" #bwl \ - : "+D"(addr), "+c"(count) : "d"(port)); \ + : "+D"(addr), "+c"(count) : "d"(port) : "memory"); \ } BUILDIO(b, b, char) From 27e7506c33d0f8afc1b49566e8994028a2847072 Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Fri, 18 Aug 2017 16:57:01 +0100 Subject: [PATCH 08/13] arm64: fpsimd: Prevent registers leaking across exec commit 096622104e14d8a1db4860bd557717067a0515d2 upstream. There are some tricky dependencies between the different stages of flushing the FPSIMD register state during exec, and these can race with context switch in ways that can cause the old task's regs to leak across. In particular, a context switch during the memset() can cause some of the task's old FPSIMD registers to reappear. Disabling preemption for this small window would be no big deal for performance: preemption is already disabled for similar scenarios like updating the FPSIMD registers in sigreturn. So, instead of rearranging things in ways that might swap existing subtle bugs for new ones, this patch just disables preemption around the FPSIMD state flushing so that races of this type can't occur here. This brings fpsimd_flush_thread() into line with other code paths. Fixes: 674c242c9323 ("arm64: flush FP/SIMD state correctly after execve()") Reviewed-by: Ard Biesheuvel Signed-off-by: Dave Martin Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/fpsimd.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 394c61db5566..1d5890f19ca3 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -157,9 +157,11 @@ void fpsimd_thread_switch(struct task_struct *next) void fpsimd_flush_thread(void) { + preempt_disable(); memset(¤t->thread.fpsimd_state, 0, sizeof(struct fpsimd_state)); fpsimd_flush_task_state(current); set_thread_flag(TIF_FOREIGN_FPSTATE); + preempt_enable(); } /* From c0c6dff9230398dd7ec9ca6c1c023c8bd44bb6cd Mon Sep 17 00:00:00 2001 From: Waiman Long Date: Wed, 8 Feb 2017 14:46:48 -0500 Subject: [PATCH 09/13] locking/spinlock/debug: Remove spinlock lockup detection code commit bc88c10d7e6900916f5e1ba3829d66a9de92b633 upstream. The current spinlock lockup detection code can sometimes produce false positives because of the unfairness of the locking algorithm itself. So the lockup detection code is now removed. Instead, we are relying on the NMI watchdog to detect potential lockup. We won't have lockup detection if the watchdog isn't running. The commented-out read-write lock lockup detection code are also removed. Signed-off-by: Waiman Long Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Sasha Levin Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1486583208-11038-1-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar Cc: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman --- kernel/locking/spinlock_debug.c | 86 ++------------------------------- 1 file changed, 5 insertions(+), 81 deletions(-) diff --git a/kernel/locking/spinlock_debug.c b/kernel/locking/spinlock_debug.c index 0374a596cffa..9aa0fccd5d43 100644 --- a/kernel/locking/spinlock_debug.c +++ b/kernel/locking/spinlock_debug.c @@ -103,38 +103,14 @@ static inline void debug_spin_unlock(raw_spinlock_t *lock) lock->owner_cpu = -1; } -static void __spin_lock_debug(raw_spinlock_t *lock) -{ - u64 i; - u64 loops = loops_per_jiffy * HZ; - - for (i = 0; i < loops; i++) { - if (arch_spin_trylock(&lock->raw_lock)) - return; - __delay(1); - } - /* lockup suspected: */ - spin_dump(lock, "lockup suspected"); -#ifdef CONFIG_SMP - trigger_all_cpu_backtrace(); -#endif - - /* - * The trylock above was causing a livelock. Give the lower level arch - * specific lock code a chance to acquire the lock. We have already - * printed a warning/backtrace at this point. The non-debug arch - * specific code might actually succeed in acquiring the lock. If it is - * not successful, the end-result is the same - there is no forward - * progress. - */ - arch_spin_lock(&lock->raw_lock); -} - +/* + * We are now relying on the NMI watchdog to detect lockup instead of doing + * the detection here with an unfair lock which can cause problem of its own. + */ void do_raw_spin_lock(raw_spinlock_t *lock) { debug_spin_lock_before(lock); - if (unlikely(!arch_spin_trylock(&lock->raw_lock))) - __spin_lock_debug(lock); + arch_spin_lock(&lock->raw_lock); debug_spin_lock_after(lock); } @@ -172,32 +148,6 @@ static void rwlock_bug(rwlock_t *lock, const char *msg) #define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg) -#if 0 /* __write_lock_debug() can lock up - maybe this can too? */ -static void __read_lock_debug(rwlock_t *lock) -{ - u64 i; - u64 loops = loops_per_jiffy * HZ; - int print_once = 1; - - for (;;) { - for (i = 0; i < loops; i++) { - if (arch_read_trylock(&lock->raw_lock)) - return; - __delay(1); - } - /* lockup suspected: */ - if (print_once) { - print_once = 0; - printk(KERN_EMERG "BUG: read-lock lockup on CPU#%d, " - "%s/%d, %p\n", - raw_smp_processor_id(), current->comm, - current->pid, lock); - dump_stack(); - } - } -} -#endif - void do_raw_read_lock(rwlock_t *lock) { RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); @@ -247,32 +197,6 @@ static inline void debug_write_unlock(rwlock_t *lock) lock->owner_cpu = -1; } -#if 0 /* This can cause lockups */ -static void __write_lock_debug(rwlock_t *lock) -{ - u64 i; - u64 loops = loops_per_jiffy * HZ; - int print_once = 1; - - for (;;) { - for (i = 0; i < loops; i++) { - if (arch_write_trylock(&lock->raw_lock)) - return; - __delay(1); - } - /* lockup suspected: */ - if (print_once) { - print_once = 0; - printk(KERN_EMERG "BUG: write-lock lockup on CPU#%d, " - "%s/%d, %p\n", - raw_smp_processor_id(), current->comm, - current->pid, lock); - dump_stack(); - } - } -} -#endif - void do_raw_write_lock(rwlock_t *lock) { debug_write_lock_before(lock); From 4099ac93838537351099859f824b8c3f9451a264 Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Fri, 7 Apr 2017 09:34:14 +0200 Subject: [PATCH 10/13] scsi: sg: protect accesses to 'reserved' page array commit 1bc0eb0446158cc76562176b80623aa119afee5b upstream. The 'reserved' page array is used as a short-cut for mapping data, saving us to allocate pages per request. However, the 'reserved' array is only capable of holding one request, so this patch introduces a mutex for protect 'sg_fd' against concurrent accesses. Signed-off-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Tested-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman [toddpoynor@google.com: backport to 3.18-4.9, fixup for bad ioctl SG_SET_FORCE_LOW_DMA code removed in later versions and not modified by the original patch.] Signed-off-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Tested-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen Signed-off-by: Todd Poynor Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/sg.c | 47 ++++++++++++++++++++++++++--------------------- 1 file changed, 26 insertions(+), 21 deletions(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index f753df25ba34..cf7e5f096988 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -142,6 +142,7 @@ typedef struct sg_fd { /* holds the state of a file descriptor */ struct sg_device *parentdp; /* owning device */ wait_queue_head_t read_wait; /* queue read until command done */ rwlock_t rq_list_lock; /* protect access to list in req_arr */ + struct mutex f_mutex; /* protect against changes in this fd */ int timeout; /* defaults to SG_DEFAULT_TIMEOUT */ int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */ Sg_scatter_hold reserve; /* buffer held for this file descriptor */ @@ -155,6 +156,7 @@ typedef struct sg_fd { /* holds the state of a file descriptor */ unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */ char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */ char mmap_called; /* 0 -> mmap() never called on this fd */ + char res_in_use; /* 1 -> 'reserve' array in use */ struct kref f_ref; struct execute_work ew; } Sg_fd; @@ -198,7 +200,6 @@ static void sg_remove_sfp(struct kref *); static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id); static Sg_request *sg_add_request(Sg_fd * sfp); static int sg_remove_request(Sg_fd * sfp, Sg_request * srp); -static int sg_res_in_use(Sg_fd * sfp); static Sg_device *sg_get_dev(int dev); static void sg_device_destroy(struct kref *kref); @@ -614,6 +615,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) } buf += SZ_SG_HEADER; __get_user(opcode, buf); + mutex_lock(&sfp->f_mutex); if (sfp->next_cmd_len > 0) { cmd_size = sfp->next_cmd_len; sfp->next_cmd_len = 0; /* reset so only this write() effected */ @@ -622,6 +624,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) if ((opcode >= 0xc0) && old_hdr.twelve_byte) cmd_size = 12; } + mutex_unlock(&sfp->f_mutex); SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp, "sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size)); /* Determine buffer size. */ @@ -721,7 +724,7 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf, sg_remove_request(sfp, srp); return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */ } - if (sg_res_in_use(sfp)) { + if (sfp->res_in_use) { sg_remove_request(sfp, srp); return -EBUSY; /* reserve buffer already being used */ } @@ -892,7 +895,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) return result; if (val) { sfp->low_dma = 1; - if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) { + if ((0 == sfp->low_dma) && !sfp->res_in_use) { val = (int) sfp->reserve.bufflen; sg_remove_scat(sfp, &sfp->reserve); sg_build_reserve(sfp, val); @@ -967,12 +970,18 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) return -EINVAL; val = min_t(int, val, max_sectors_bytes(sdp->device->request_queue)); + mutex_lock(&sfp->f_mutex); if (val != sfp->reserve.bufflen) { - if (sg_res_in_use(sfp) || sfp->mmap_called) + if (sfp->mmap_called || + sfp->res_in_use) { + mutex_unlock(&sfp->f_mutex); return -EBUSY; + } + sg_remove_scat(sfp, &sfp->reserve); sg_build_reserve(sfp, val); } + mutex_unlock(&sfp->f_mutex); return 0; case SG_GET_RESERVED_SIZE: val = min_t(int, sfp->reserve.bufflen, @@ -1727,13 +1736,22 @@ sg_start_req(Sg_request *srp, unsigned char *cmd) md = &map_data; if (md) { - if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen) + mutex_lock(&sfp->f_mutex); + if (dxfer_len <= rsv_schp->bufflen && + !sfp->res_in_use) { + sfp->res_in_use = 1; sg_link_reserve(sfp, srp, dxfer_len); - else { + } else if ((hp->flags & SG_FLAG_MMAP_IO) && sfp->res_in_use) { + mutex_unlock(&sfp->f_mutex); + return -EBUSY; + } else { res = sg_build_indirect(req_schp, sfp, dxfer_len); - if (res) + if (res) { + mutex_unlock(&sfp->f_mutex); return res; + } } + mutex_unlock(&sfp->f_mutex); md->pages = req_schp->pages; md->page_order = req_schp->page_order; @@ -2135,6 +2153,7 @@ sg_add_sfp(Sg_device * sdp) rwlock_init(&sfp->rq_list_lock); kref_init(&sfp->f_ref); + mutex_init(&sfp->f_mutex); sfp->timeout = SG_DEFAULT_TIMEOUT; sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER; sfp->force_packid = SG_DEF_FORCE_PACK_ID; @@ -2210,20 +2229,6 @@ sg_remove_sfp(struct kref *kref) schedule_work(&sfp->ew.work); } -static int -sg_res_in_use(Sg_fd * sfp) -{ - const Sg_request *srp; - unsigned long iflags; - - read_lock_irqsave(&sfp->rq_list_lock, iflags); - for (srp = sfp->headrp; srp; srp = srp->nextrp) - if (srp->res_used) - break; - read_unlock_irqrestore(&sfp->rq_list_lock, iflags); - return srp ? 1 : 0; -} - #ifdef CONFIG_SCSI_PROC_FS static int sg_idr_max_id(int id, void *p, void *data) From c47c52cde806f32c4da1e455874f6aa154c06aca Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Mon, 24 Apr 2017 10:26:36 +0200 Subject: [PATCH 11/13] scsi: sg: reset 'res_in_use' after unlinking reserved array commit e791ce27c3f6a1d3c746fd6a8f8e36c9540ec6f9 upstream. Once the reserved page array is unused we can reset the 'res_in_use' state; here we can do a lazy update without holding the mutex as we only need to check against concurrent access, not concurrent release. [mkp: checkpatch] Fixes: 1bc0eb044615 ("scsi: sg: protect accesses to 'reserved' page array") Signed-off-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen Cc: Todd Poynor Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/sg.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index cf7e5f096988..fed37aabf828 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -2042,6 +2042,8 @@ sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp) req_schp->sglist_len = 0; sfp->save_scat_len = 0; srp->res_used = 0; + /* Called without mutex lock to avoid deadlock */ + sfp->res_in_use = 0; } static Sg_request * From 529ada21ff9e37a14fd02ab1fb9d58d71d7a0d9e Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 31 Aug 2017 09:09:54 +0200 Subject: [PATCH 12/13] lz4: fix bogus gcc warning MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When building lz4 under gcc-7 we get the following bogus warning: CC [M] lib/lz4/lz4hc_compress.o lib/lz4/lz4hc_compress.c: In function ‘lz4hc_compress’: lib/lz4/lz4hc_compress.c:179:42: warning: ‘delta’ may be used uninitialized in this function [-Wmaybe-uninitialized] chaintable[(size_t)(ptr) & MAXD_MASK] = delta; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~ lib/lz4/lz4hc_compress.c:134:6: note: ‘delta’ was declared here u16 delta; ^~~~~ This doesn't show up in the 4.4-stable tree due to us turning off warnings like this. It also doesn't show up in newer kernel versions as this code was totally rewritten. So for now, to get the 4.9-stable tree to build with 0 warnings on x86 allmodconfig, let's just shut the compiler up by initializing the variable to 0, despite it not really doing anything. To be far, this code is crazy complex, so the fact that gcc can't determine if the variable is really used or not isn't that bad, I'd blame the code here instead of the compiler. Signed-off-by: Greg Kroah-Hartman --- lib/lz4/lz4hc_compress.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/lz4/lz4hc_compress.c b/lib/lz4/lz4hc_compress.c index f344f76b6559..6b2e046a9c61 100644 --- a/lib/lz4/lz4hc_compress.c +++ b/lib/lz4/lz4hc_compress.c @@ -131,7 +131,7 @@ static inline int lz4hc_insertandfindbestmatch(struct lz4hc_data *hc4, #endif int nbattempts = MAX_NB_ATTEMPTS; size_t repl = 0, ml = 0; - u16 delta; + u16 delta = 0; /* HC4 match finder */ lz4hc_insert(hc4, ip); From 458ca52f1564938c158d271f45bce0bc6ede2b3f Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Sat, 2 Sep 2017 07:08:05 +0200 Subject: [PATCH 13/13] Linux 4.9.47 --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 846ef1b57a02..a0abbfc15a49 100644 --- a/Makefile +++ b/Makefile @@ -1,6 +1,6 @@ VERSION = 4 PATCHLEVEL = 9 -SUBLEVEL = 46 +SUBLEVEL = 47 EXTRAVERSION = NAME = Roaring Lionus