November 2017 - Linux-stable-mirror

[Linux-stable-mirror] WTF: patch "[PATCH] MIPS: pci: Remove KERN_WARN instance inside the mt7620 driver" was seriously submitted to be applied to the 4.9-stable tree?

by gregkh＠linuxfoundation.org

The patch below was submitted to be applied to the 4.9-stable tree. I fail to see how this patch meets the stable kernel rules as found at Documentation/process/stable-kernel-rules.rst. I could be totally wrong, and if so, please respond to <stable(a)vger.kernel.org> and let me know why this patch should be applied. Otherwise, it is now dropped from my patch queues, never to be seen again. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 8593b18ad348733b5d5ddfa0c79dcabf51dff308 Mon Sep 17 00:00:00 2001 From: John Crispin <john(a)phrozen.org> Date: Mon, 20 Feb 2017 10:29:43 +0100 Subject: [PATCH] MIPS: pci: Remove KERN_WARN instance inside the mt7620 driver Switch the printk() call to the prefered pr_warn() api. Fixes: 7e5873d3755c ("MIPS: pci: Add MT7620a PCIE driver") Signed-off-by: John Crispin <john(a)phrozen.org> Cc: Ralf Baechle <ralf(a)linux-mips.org> Cc: linux-mips(a)linux-mips.org Cc: <stable(a)vger.kernel.org> # 4.5+ Patchwork: https://patchwork.linux-mips.org/patch/15321/ Signed-off-by: James Hogan <jhogan(a)kernel.org> diff --git a/arch/mips/pci/pci-mt7620.c b/arch/mips/pci/pci-mt7620.c index 22e4c22e750b..1a0b80a1cc4a 100644 --- a/arch/mips/pci/pci-mt7620.c +++ b/arch/mips/pci/pci-mt7620.c @@ -120,7 +120,7 @@ static int wait_pciephy_busy(void) else break; if (retry++ > WAITRETRY_MAX) { - printk(KERN_WARN "PCIE-PHY retry failed.\n"); + pr_warn("PCIE-PHY retry failed.\n"); return -1; } }

7 years, 1 month

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[Linux-stable-mirror] WTF: patch "[PATCH] MIPS: pci: Remove KERN_WARN instance inside the mt7620 driver" was seriously submitted to be applied to the 4.14-stable tree?

by gregkh＠linuxfoundation.org

The patch below was submitted to be applied to the 4.14-stable tree. I fail to see how this patch meets the stable kernel rules as found at Documentation/process/stable-kernel-rules.rst. I could be totally wrong, and if so, please respond to <stable(a)vger.kernel.org> and let me know why this patch should be applied. Otherwise, it is now dropped from my patch queues, never to be seen again. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 8593b18ad348733b5d5ddfa0c79dcabf51dff308 Mon Sep 17 00:00:00 2001 From: John Crispin <john(a)phrozen.org> Date: Mon, 20 Feb 2017 10:29:43 +0100 Subject: [PATCH] MIPS: pci: Remove KERN_WARN instance inside the mt7620 driver Switch the printk() call to the prefered pr_warn() api. Fixes: 7e5873d3755c ("MIPS: pci: Add MT7620a PCIE driver") Signed-off-by: John Crispin <john(a)phrozen.org> Cc: Ralf Baechle <ralf(a)linux-mips.org> Cc: linux-mips(a)linux-mips.org Cc: <stable(a)vger.kernel.org> # 4.5+ Patchwork: https://patchwork.linux-mips.org/patch/15321/ Signed-off-by: James Hogan <jhogan(a)kernel.org> diff --git a/arch/mips/pci/pci-mt7620.c b/arch/mips/pci/pci-mt7620.c index 22e4c22e750b..1a0b80a1cc4a 100644 --- a/arch/mips/pci/pci-mt7620.c +++ b/arch/mips/pci/pci-mt7620.c @@ -120,7 +120,7 @@ static int wait_pciephy_busy(void) else break; if (retry++ > WAITRETRY_MAX) { - printk(KERN_WARN "PCIE-PHY retry failed.\n"); + pr_warn("PCIE-PHY retry failed.\n"); return -1; } }

7 years, 1 month

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[Linux-stable-mirror] FAILED: patch "[PATCH] MIPS: cmpxchg64() and HAVE_VIRT_CPU_ACCOUNTING_GEN don't work" failed to apply to 4.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From a3f143106596d739e7fbc4b84c96b1475247d876 Mon Sep 17 00:00:00 2001 From: Ben Hutchings <ben(a)decadent.org.uk> Date: Wed, 4 Oct 2017 03:46:14 +0100 Subject: [PATCH] MIPS: cmpxchg64() and HAVE_VIRT_CPU_ACCOUNTING_GEN don't work for 32-bit SMP __cmpxchg64_local_generic() is atomic only w.r.t tasks and interrupts on the same CPU (that's what the 'local' means). We can't use it to implement cmpxchg64() in SMP configurations. So, for 32-bit SMP configurations: - Don't define cmpxchg64() - Don't enable HAVE_VIRT_CPU_ACCOUNTING_GEN, which requires it Fixes: e2093c7b03c1 ("MIPS: Fall back to generic implementation of ...") Fixes: bb877e96bea1 ("MIPS: Add support for full dynticks CPU time accounting") Signed-off-by: Ben Hutchings <ben(a)decadent.org.uk> Cc: Ralf Baechle <ralf(a)linux-mips.org> Cc: Deng-Cheng Zhu <dengcheng.zhu(a)mips.com> Cc: linux-mips(a)linux-mips.org Cc: <stable(a)vger.kernel.org> # 4.1+ Patchwork: https://patchwork.linux-mips.org/patch/17413/ Signed-off-by: James Hogan <jhogan(a)kernel.org> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 43411118dd4f..b09b644cd57c 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -64,7 +64,7 @@ config MIPS select HAVE_PERF_EVENTS select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_SYSCALL_TRACEPOINTS - select HAVE_VIRT_CPU_ACCOUNTING_GEN + select HAVE_VIRT_CPU_ACCOUNTING_GEN if 64BIT || !SMP select IRQ_FORCED_THREADING select MODULES_USE_ELF_RELA if MODULES && 64BIT select MODULES_USE_ELF_REL if MODULES diff --git a/arch/mips/include/asm/cmpxchg.h b/arch/mips/include/asm/cmpxchg.h index 903f3bf48419..ae2b4583b486 100644 --- a/arch/mips/include/asm/cmpxchg.h +++ b/arch/mips/include/asm/cmpxchg.h @@ -202,8 +202,10 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, #else #include <asm-generic/cmpxchg-local.h> #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) +#ifndef CONFIG_SMP #define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n)) #endif +#endif #undef __scbeqz

7 years, 1 month

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[Linux-stable-mirror] FAILED: patch "[PATCH] MIPS: cmpxchg64() and HAVE_VIRT_CPU_ACCOUNTING_GEN don't work" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From a3f143106596d739e7fbc4b84c96b1475247d876 Mon Sep 17 00:00:00 2001 From: Ben Hutchings <ben(a)decadent.org.uk> Date: Wed, 4 Oct 2017 03:46:14 +0100 Subject: [PATCH] MIPS: cmpxchg64() and HAVE_VIRT_CPU_ACCOUNTING_GEN don't work for 32-bit SMP __cmpxchg64_local_generic() is atomic only w.r.t tasks and interrupts on the same CPU (that's what the 'local' means). We can't use it to implement cmpxchg64() in SMP configurations. So, for 32-bit SMP configurations: - Don't define cmpxchg64() - Don't enable HAVE_VIRT_CPU_ACCOUNTING_GEN, which requires it Fixes: e2093c7b03c1 ("MIPS: Fall back to generic implementation of ...") Fixes: bb877e96bea1 ("MIPS: Add support for full dynticks CPU time accounting") Signed-off-by: Ben Hutchings <ben(a)decadent.org.uk> Cc: Ralf Baechle <ralf(a)linux-mips.org> Cc: Deng-Cheng Zhu <dengcheng.zhu(a)mips.com> Cc: linux-mips(a)linux-mips.org Cc: <stable(a)vger.kernel.org> # 4.1+ Patchwork: https://patchwork.linux-mips.org/patch/17413/ Signed-off-by: James Hogan <jhogan(a)kernel.org> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 43411118dd4f..b09b644cd57c 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -64,7 +64,7 @@ config MIPS select HAVE_PERF_EVENTS select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_SYSCALL_TRACEPOINTS - select HAVE_VIRT_CPU_ACCOUNTING_GEN + select HAVE_VIRT_CPU_ACCOUNTING_GEN if 64BIT || !SMP select IRQ_FORCED_THREADING select MODULES_USE_ELF_RELA if MODULES && 64BIT select MODULES_USE_ELF_REL if MODULES diff --git a/arch/mips/include/asm/cmpxchg.h b/arch/mips/include/asm/cmpxchg.h index 903f3bf48419..ae2b4583b486 100644 --- a/arch/mips/include/asm/cmpxchg.h +++ b/arch/mips/include/asm/cmpxchg.h @@ -202,8 +202,10 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, #else #include <asm-generic/cmpxchg-local.h> #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) +#ifndef CONFIG_SMP #define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n)) #endif +#endif #undef __scbeqz

7 years, 1 month

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[Linux-stable-mirror] WTF: patch "[PATCH] arm64: mm: Remove arch_apei_flush_tlb_one()" was seriously submitted to be applied to the 4.14-stable tree?

by gregkh＠linuxfoundation.org

The patch below was submitted to be applied to the 4.14-stable tree. I fail to see how this patch meets the stable kernel rules as found at Documentation/process/stable-kernel-rules.rst. I could be totally wrong, and if so, please respond to <stable(a)vger.kernel.org> and let me know why this patch should be applied. Otherwise, it is now dropped from my patch queues, never to be seen again. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 18b4b276b490a8b9f86c512de8a6054c27bb87c2 Mon Sep 17 00:00:00 2001 From: James Morse <james.morse(a)arm.com> Date: Mon, 6 Nov 2017 18:44:26 +0000 Subject: [PATCH] arm64: mm: Remove arch_apei_flush_tlb_one() Nothing calls arch_apei_flush_tlb_one() anymore, instead relying on __set_fixmap() to do the invalidation. Remove it. Move the IPI-considered-harmful comment to __set_fixmap(). Signed-off-by: James Morse <james.morse(a)arm.com> Acked-by: Will Deacon <will.deacon(a)arm.com> Tested-by: Tyler Baicar <tbaicar(a)codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com> Cc: All applicable <stable(a)vger.kernel.org> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index 59cca1d6ec54..32f465a80e4e 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -126,18 +126,6 @@ static inline const char *acpi_get_enable_method(int cpu) */ #define acpi_disable_cmcff 1 pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr); - -/* - * Despite its name, this function must still broadcast the TLB - * invalidation in order to ensure other CPUs don't end up with junk - * entries as a result of speculation. Unusually, its also called in - * IRQ context (ghes_iounmap_irq) so if we ever need to use IPIs for - * TLB broadcasting, then we're in trouble here. - */ -static inline void arch_apei_flush_tlb_one(unsigned long addr) -{ - flush_tlb_kernel_range(addr, addr + PAGE_SIZE); -} #endif /* CONFIG_ACPI_APEI */ #ifdef CONFIG_ACPI_NUMA diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index f1eb15e0e864..267d2b79d52d 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -778,6 +778,10 @@ void __init early_fixmap_init(void) } } +/* + * Unusually, this is also called in IRQ context (ghes_iounmap_irq) so if we + * ever need to use IPIs for TLB broadcasting, then we're in trouble here. + */ void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) {

7 years, 1 month

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[Linux-stable-mirror] Patch "sched: Make resched_cpu() unconditional" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled sched: Make resched_cpu() unconditional to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: sched-make-resched_cpu-unconditional.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 7c2102e56a3f7d85b5d8f33efbd7aecc1f36fdd8 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" <paulmck(a)linux.vnet.ibm.com> Date: Mon, 18 Sep 2017 08:54:40 -0700 Subject: sched: Make resched_cpu() unconditional From: Paul E. McKenney <paulmck(a)linux.vnet.ibm.com> commit 7c2102e56a3f7d85b5d8f33efbd7aecc1f36fdd8 upstream. The current implementation of synchronize_sched_expedited() incorrectly assumes that resched_cpu() is unconditional, which it is not. This means that synchronize_sched_expedited() can hang when resched_cpu()'s trylock fails as follows (analysis by Neeraj Upadhyay): o CPU1 is waiting for expedited wait to complete: sync_rcu_exp_select_cpus rdp->exp_dynticks_snap & 0x1 // returns 1 for CPU5 IPI sent to CPU5 synchronize_sched_expedited_wait ret = swait_event_timeout(rsp->expedited_wq, sync_rcu_preempt_exp_done(rnp_root), jiffies_stall); expmask = 0x20, CPU 5 in idle path (in cpuidle_enter()) o CPU5 handles IPI and fails to acquire rq lock. Handles IPI sync_sched_exp_handler resched_cpu returns while failing to try lock acquire rq->lock need_resched is not set o CPU5 calls rcu_idle_enter() and as need_resched is not set, goes to idle (schedule() is not called). o CPU 1 reports RCU stall. Given that resched_cpu() is now used only by RCU, this commit fixes the assumption by making resched_cpu() unconditional. Reported-by: Neeraj Upadhyay <neeraju(a)codeaurora.org> Suggested-by: Neeraj Upadhyay <neeraju(a)codeaurora.org> Signed-off-by: Paul E. McKenney <paulmck(a)linux.vnet.ibm.com> Acked-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org> Acked-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- kernel/sched/core.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -507,8 +507,7 @@ void resched_cpu(int cpu) struct rq *rq = cpu_rq(cpu); unsigned long flags; - if (!raw_spin_trylock_irqsave(&rq->lock, flags)) - return; + raw_spin_lock_irqsave(&rq->lock, flags); resched_curr(rq); raw_spin_unlock_irqrestore(&rq->lock, flags); } Patches currently in stable-queue which might be from paulmck(a)linux.vnet.ibm.com are queue-4.9/sched-make-resched_cpu-unconditional.patch

7 years, 1 month

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[Linux-stable-mirror] Patch "lib/mpi: call cond_resched() from mpi_powm() loop" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled lib/mpi: call cond_resched() from mpi_powm() loop to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: lib-mpi-call-cond_resched-from-mpi_powm-loop.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 1d9ddde12e3c9bab7f3d3484eb9446315e3571ca Mon Sep 17 00:00:00 2001 From: Eric Biggers <ebiggers(a)google.com> Date: Tue, 7 Nov 2017 14:15:27 -0800 Subject: lib/mpi: call cond_resched() from mpi_powm() loop From: Eric Biggers <ebiggers(a)google.com> commit 1d9ddde12e3c9bab7f3d3484eb9446315e3571ca upstream. On a non-preemptible kernel, if KEYCTL_DH_COMPUTE is called with the largest permitted inputs (16384 bits), the kernel spends 10+ seconds doing modular exponentiation in mpi_powm() without rescheduling. If all threads do it, it locks up the system. Moreover, it can cause rcu_sched-stall warnings. Notwithstanding the insanity of doing this calculation in kernel mode rather than in userspace, fix it by calling cond_resched() as each bit from the exponent is processed. It's still noninterruptible, but at least it's preemptible now. Do the cond_resched() once per bit rather than once per MPI limb because each limb might still easily take 100+ milliseconds on slow CPUs. Signed-off-by: Eric Biggers <ebiggers(a)google.com> Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- lib/mpi/mpi-pow.c | 2 ++ 1 file changed, 2 insertions(+) --- a/lib/mpi/mpi-pow.c +++ b/lib/mpi/mpi-pow.c @@ -26,6 +26,7 @@ * however I decided to publish this code under the plain GPL. */ +#include <linux/sched.h> #include <linux/string.h> #include "mpi-internal.h" #include "longlong.h" @@ -256,6 +257,7 @@ int mpi_powm(MPI res, MPI base, MPI exp, } e <<= 1; c--; + cond_resched(); } i--; Patches currently in stable-queue which might be from ebiggers(a)google.com are queue-4.9/lib-mpi-call-cond_resched-from-mpi_powm-loop.patch

7 years, 1 month

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[Linux-stable-mirror] Patch "sched: Make resched_cpu() unconditional" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled sched: Make resched_cpu() unconditional to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: sched-make-resched_cpu-unconditional.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 7c2102e56a3f7d85b5d8f33efbd7aecc1f36fdd8 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" <paulmck(a)linux.vnet.ibm.com> Date: Mon, 18 Sep 2017 08:54:40 -0700 Subject: sched: Make resched_cpu() unconditional From: Paul E. McKenney <paulmck(a)linux.vnet.ibm.com> commit 7c2102e56a3f7d85b5d8f33efbd7aecc1f36fdd8 upstream. The current implementation of synchronize_sched_expedited() incorrectly assumes that resched_cpu() is unconditional, which it is not. This means that synchronize_sched_expedited() can hang when resched_cpu()'s trylock fails as follows (analysis by Neeraj Upadhyay): o CPU1 is waiting for expedited wait to complete: sync_rcu_exp_select_cpus rdp->exp_dynticks_snap & 0x1 // returns 1 for CPU5 IPI sent to CPU5 synchronize_sched_expedited_wait ret = swait_event_timeout(rsp->expedited_wq, sync_rcu_preempt_exp_done(rnp_root), jiffies_stall); expmask = 0x20, CPU 5 in idle path (in cpuidle_enter()) o CPU5 handles IPI and fails to acquire rq lock. Handles IPI sync_sched_exp_handler resched_cpu returns while failing to try lock acquire rq->lock need_resched is not set o CPU5 calls rcu_idle_enter() and as need_resched is not set, goes to idle (schedule() is not called). o CPU 1 reports RCU stall. Given that resched_cpu() is now used only by RCU, this commit fixes the assumption by making resched_cpu() unconditional. Reported-by: Neeraj Upadhyay <neeraju(a)codeaurora.org> Suggested-by: Neeraj Upadhyay <neeraju(a)codeaurora.org> Signed-off-by: Paul E. McKenney <paulmck(a)linux.vnet.ibm.com> Acked-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org> Acked-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- kernel/sched/core.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -600,8 +600,7 @@ void resched_cpu(int cpu) struct rq *rq = cpu_rq(cpu); unsigned long flags; - if (!raw_spin_trylock_irqsave(&rq->lock, flags)) - return; + raw_spin_lock_irqsave(&rq->lock, flags); resched_curr(rq); raw_spin_unlock_irqrestore(&rq->lock, flags); } Patches currently in stable-queue which might be from paulmck(a)linux.vnet.ibm.com are queue-4.4/sched-make-resched_cpu-unconditional.patch

7 years, 1 month

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[Linux-stable-mirror] Patch "lib/mpi: call cond_resched() from mpi_powm() loop" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled lib/mpi: call cond_resched() from mpi_powm() loop to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: lib-mpi-call-cond_resched-from-mpi_powm-loop.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 1d9ddde12e3c9bab7f3d3484eb9446315e3571ca Mon Sep 17 00:00:00 2001 From: Eric Biggers <ebiggers(a)google.com> Date: Tue, 7 Nov 2017 14:15:27 -0800 Subject: lib/mpi: call cond_resched() from mpi_powm() loop From: Eric Biggers <ebiggers(a)google.com> commit 1d9ddde12e3c9bab7f3d3484eb9446315e3571ca upstream. On a non-preemptible kernel, if KEYCTL_DH_COMPUTE is called with the largest permitted inputs (16384 bits), the kernel spends 10+ seconds doing modular exponentiation in mpi_powm() without rescheduling. If all threads do it, it locks up the system. Moreover, it can cause rcu_sched-stall warnings. Notwithstanding the insanity of doing this calculation in kernel mode rather than in userspace, fix it by calling cond_resched() as each bit from the exponent is processed. It's still noninterruptible, but at least it's preemptible now. Do the cond_resched() once per bit rather than once per MPI limb because each limb might still easily take 100+ milliseconds on slow CPUs. Signed-off-by: Eric Biggers <ebiggers(a)google.com> Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- lib/mpi/mpi-pow.c | 2 ++ 1 file changed, 2 insertions(+) --- a/lib/mpi/mpi-pow.c +++ b/lib/mpi/mpi-pow.c @@ -26,6 +26,7 @@ * however I decided to publish this code under the plain GPL. */ +#include <linux/sched.h> #include <linux/string.h> #include "mpi-internal.h" #include "longlong.h" @@ -256,6 +257,7 @@ int mpi_powm(MPI res, MPI base, MPI exp, } e <<= 1; c--; + cond_resched(); } i--; Patches currently in stable-queue which might be from ebiggers(a)google.com are queue-4.4/lib-mpi-call-cond_resched-from-mpi_powm-loop.patch

7 years, 1 month

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[Linux-stable-mirror] Patch "serdev: fix registration of second slave" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled serdev: fix registration of second slave to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: serdev-fix-registration-of-second-slave.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 08fcee289f341786eb3b44e5f2d1dc850943238e Mon Sep 17 00:00:00 2001 From: Johan Hovold <johan(a)kernel.org> Date: Tue, 10 Oct 2017 18:09:49 +0200 Subject: serdev: fix registration of second slave From: Johan Hovold <johan(a)kernel.org> commit 08fcee289f341786eb3b44e5f2d1dc850943238e upstream. Serdev currently only supports a single slave device, but the required sanity checks to prevent further registration attempts were missing. If a serial-port node has two child nodes with compatible properties, the OF code would try to register two slave devices using the same id and name. Driver core will not allow this (and there will be loud complaints), but the controller's slave pointer would already have been set to address of the soon to be deallocated second struct serdev_device. As the first slave device remains registered, this can lead to later use-after-free issues when the slave callbacks are accessed. Note that while the serdev registration helpers are exported, they are typically only called by serdev core. Any other (out-of-tree) callers must serialise registration and deregistration themselves. Fixes: cd6484e1830b ("serdev: Introduce new bus for serial attached devices") Cc: Rob Herring <robh(a)kernel.org> Signed-off-by: Johan Hovold <johan(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/tty/serdev/core.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) --- a/drivers/tty/serdev/core.c +++ b/drivers/tty/serdev/core.c @@ -65,21 +65,32 @@ static int serdev_uevent(struct device * */ int serdev_device_add(struct serdev_device *serdev) { + struct serdev_controller *ctrl = serdev->ctrl; struct device *parent = serdev->dev.parent; int err; dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr); + /* Only a single slave device is currently supported. */ + if (ctrl->serdev) { + dev_err(&serdev->dev, "controller busy\n"); + return -EBUSY; + } + ctrl->serdev = serdev; + err = device_add(&serdev->dev); if (err < 0) { dev_err(&serdev->dev, "Can't add %s, status %d\n", dev_name(&serdev->dev), err); - goto err_device_add; + goto err_clear_serdev; } dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev)); -err_device_add: + return 0; + +err_clear_serdev: + ctrl->serdev = NULL; return err; } EXPORT_SYMBOL_GPL(serdev_device_add); @@ -90,7 +101,10 @@ EXPORT_SYMBOL_GPL(serdev_device_add); */ void serdev_device_remove(struct serdev_device *serdev) { + struct serdev_controller *ctrl = serdev->ctrl; + device_unregister(&serdev->dev); + ctrl->serdev = NULL; } EXPORT_SYMBOL_GPL(serdev_device_remove); @@ -295,7 +309,6 @@ struct serdev_device *serdev_device_allo return NULL; serdev->ctrl = ctrl; - ctrl->serdev = serdev; device_initialize(&serdev->dev); serdev->dev.parent = &ctrl->dev; serdev->dev.bus = &serdev_bus_type; Patches currently in stable-queue which might be from johan(a)kernel.org are queue-4.14/serdev-fix-registration-of-second-slave.patch

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Linux-stable-mirror November 2017