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2020-08-26KVM: arm/arm64: Don't reschedule in unmap_stage2_range()Will Deacon1-8/+0
Upstream commits fdfe7cbd5880 ("KVM: Pass MMU notifier range flags to kvm_unmap_hva_range()") and b5331379bc62 ("KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set") fix a "sleeping from invalid context" BUG caused by unmap_stage2_range() attempting to reschedule when called on the OOM path. Unfortunately, these patches rely on the MMU notifier callback being passed knowledge about whether or not blocking is permitted, which was introduced in 4.19. Rather than backport this considerable amount of infrastructure just for KVM on arm, instead just remove the conditional reschedule. Cc: <stable@vger.kernel.org> # v4.4 only Cc: Marc Zyngier <maz@kernel.org> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will@kernel.org> Acked-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-26powerpc: Allow 4224 bytes of stack expansion for the signal frameMichael Ellerman1-2/+5
commit 63dee5df43a31f3844efabc58972f0a206ca4534 upstream. We have powerpc specific logic in our page fault handling to decide if an access to an unmapped address below the stack pointer should expand the stack VMA. The code was originally added in 2004 "ported from 2.4". The rough logic is that the stack is allowed to grow to 1MB with no extra checking. Over 1MB the access must be within 2048 bytes of the stack pointer, or be from a user instruction that updates the stack pointer. The 2048 byte allowance below the stack pointer is there to cover the 288 byte "red zone" as well as the "about 1.5kB" needed by the signal delivery code. Unfortunately since then the signal frame has expanded, and is now 4224 bytes on 64-bit kernels with transactional memory enabled. This means if a process has consumed more than 1MB of stack, and its stack pointer lies less than 4224 bytes from the next page boundary, signal delivery will fault when trying to expand the stack and the process will see a SEGV. The total size of the signal frame is the size of struct rt_sigframe (which includes the red zone) plus __SIGNAL_FRAMESIZE (128 bytes on 64-bit). The 2048 byte allowance was correct until 2008 as the signal frame was: struct rt_sigframe { struct ucontext uc; /* 0 1440 */ /* --- cacheline 11 boundary (1408 bytes) was 32 bytes ago --- */ long unsigned int _unused[2]; /* 1440 16 */ unsigned int tramp[6]; /* 1456 24 */ struct siginfo * pinfo; /* 1480 8 */ void * puc; /* 1488 8 */ struct siginfo info; /* 1496 128 */ /* --- cacheline 12 boundary (1536 bytes) was 88 bytes ago --- */ char abigap[288]; /* 1624 288 */ /* size: 1920, cachelines: 15, members: 7 */ /* padding: 8 */ }; 1920 + 128 = 2048 Then in commit ce48b2100785 ("powerpc: Add VSX context save/restore, ptrace and signal support") (Jul 2008) the signal frame expanded to 2304 bytes: struct rt_sigframe { struct ucontext uc; /* 0 1696 */ <-- /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */ long unsigned int _unused[2]; /* 1696 16 */ unsigned int tramp[6]; /* 1712 24 */ struct siginfo * pinfo; /* 1736 8 */ void * puc; /* 1744 8 */ struct siginfo info; /* 1752 128 */ /* --- cacheline 14 boundary (1792 bytes) was 88 bytes ago --- */ char abigap[288]; /* 1880 288 */ /* size: 2176, cachelines: 17, members: 7 */ /* padding: 8 */ }; 2176 + 128 = 2304 At this point we should have been exposed to the bug, though as far as I know it was never reported. I no longer have a system old enough to easily test on. Then in 2010 commit 320b2b8de126 ("mm: keep a guard page below a grow-down stack segment") caused our stack expansion code to never trigger, as there was always a VMA found for a write up to PAGE_SIZE below r1. That meant the bug was hidden as we continued to expand the signal frame in commit 2b0a576d15e0 ("powerpc: Add new transactional memory state to the signal context") (Feb 2013): struct rt_sigframe { struct ucontext uc; /* 0 1696 */ /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */ struct ucontext uc_transact; /* 1696 1696 */ <-- /* --- cacheline 26 boundary (3328 bytes) was 64 bytes ago --- */ long unsigned int _unused[2]; /* 3392 16 */ unsigned int tramp[6]; /* 3408 24 */ struct siginfo * pinfo; /* 3432 8 */ void * puc; /* 3440 8 */ struct siginfo info; /* 3448 128 */ /* --- cacheline 27 boundary (3456 bytes) was 120 bytes ago --- */ char abigap[288]; /* 3576 288 */ /* size: 3872, cachelines: 31, members: 8 */ /* padding: 8 */ /* last cacheline: 32 bytes */ }; 3872 + 128 = 4000 And commit 573ebfa6601f ("powerpc: Increase stack redzone for 64-bit userspace to 512 bytes") (Feb 2014): struct rt_sigframe { struct ucontext uc; /* 0 1696 */ /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */ struct ucontext uc_transact; /* 1696 1696 */ /* --- cacheline 26 boundary (3328 bytes) was 64 bytes ago --- */ long unsigned int _unused[2]; /* 3392 16 */ unsigned int tramp[6]; /* 3408 24 */ struct siginfo * pinfo; /* 3432 8 */ void * puc; /* 3440 8 */ struct siginfo info; /* 3448 128 */ /* --- cacheline 27 boundary (3456 bytes) was 120 bytes ago --- */ char abigap[512]; /* 3576 512 */ <-- /* size: 4096, cachelines: 32, members: 8 */ /* padding: 8 */ }; 4096 + 128 = 4224 Then finally in 2017, commit 1be7107fbe18 ("mm: larger stack guard gap, between vmas") exposed us to the existing bug, because it changed the stack VMA to be the correct/real size, meaning our stack expansion code is now triggered. Fix it by increasing the allowance to 4224 bytes. Hard-coding 4224 is obviously unsafe against future expansions of the signal frame in the same way as the existing code. We can't easily use sizeof() because the signal frame structure is not in a header. We will either fix that, or rip out all the custom stack expansion checking logic entirely. Fixes: ce48b2100785 ("powerpc: Add VSX context save/restore, ptrace and signal support") Cc: stable@vger.kernel.org # v2.6.27+ Reported-by: Tom Lane <tgl@sss.pgh.pa.us> Tested-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724092528.1578671-2-mpe@ellerman.id.au Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-26alpha: fix annotation of io{read,write}{16,32}be()Luc Van Oostenryck1-4/+4
[ Upstream commit bd72866b8da499e60633ff28f8a4f6e09ca78efe ] These accessors must be used to read/write a big-endian bus. The value returned or written is native-endian. However, these accessors are defined using be{16,32}_to_cpu() or cpu_to_be{16,32}() to make the endian conversion but these expect a __be{16,32} when none is present. Keeping them would need a force cast that would solve nothing at all. So, do the conversion using swab{16,32}, like done in asm-generic for similar situations. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Link: http://lkml.kernel.org/r/20200622114232.80039-1-luc.vanoostenryck@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26m68knommu: fix overwriting of bits in ColdFire V3 cache controlGreg Ungerer1-3/+3
[ Upstream commit bdee0e793cea10c516ff48bf3ebb4ef1820a116b ] The Cache Control Register (CACR) of the ColdFire V3 has bits that control high level caching functions, and also enable/disable the use of the alternate stack pointer register (the EUSP bit) to provide separate supervisor and user stack pointer registers. The code as it is today will blindly clear the EUSP bit on cache actions like invalidation. So it is broken for this case - and that will result in failed booting (interrupt entry and exit processing will be completely hosed). This only affects ColdFire V3 parts that support the alternate stack register (like the 5329 for example) - generally speaking new parts do, older parts don't. It has no impact on ColdFire V3 parts with the single stack pointer, like the 5307 for example. Fix the cache bit defines used, so they maintain the EUSP bit when carrying out cache actions through the CACR register. Signed-off-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21sh: landisk: Add missing initialization of sh_io_port_baseGeert Uytterhoeven1-0/+3
[ Upstream commit 0c64a0dce51faa9c706fdf1f957d6f19878f4b81 ] The Landisk setup code maps the CF IDE area using ioremap_prot(), and passes the resulting virtual addresses to the pata_platform driver, disguising them as I/O port addresses. Hence the pata_platform driver translates them again using ioport_map(). As CONFIG_GENERIC_IOMAP=n, and CONFIG_HAS_IOPORT_MAP=y, the SuperH-specific mapping code in arch/sh/kernel/ioport.c translates I/O port addresses to virtual addresses by adding sh_io_port_base, which defaults to -1, thus breaking the assumption of an identity mapping. Fix this by setting sh_io_port_base to zero. Fixes: 37b7a97884ba64bf ("sh: machvec IO death.") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Rich Felker <dalias@libc.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21pseries: Fix 64 bit logical memory block panicAnton Blanchard1-1/+1
commit 89c140bbaeee7a55ed0360a88f294ead2b95201b upstream. Booting with a 4GB LMB size causes us to panic: qemu-system-ppc64: OS terminated: OS panic: Memory block size not suitable: 0x0 Fix pseries_memory_block_size() to handle 64 bit LMBs. Cc: stable@vger.kernel.org Signed-off-by: Anton Blanchard <anton@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200715000820.1255764-1-anton@ozlabs.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21MIPS: CPU#0 is not hotpluggableHuacai Chen1-1/+1
commit 9cce844abf07b683cff5f0273977d5f8d0af94c7 upstream. Now CPU#0 is not hotpluggable on MIPS, so prevent to create /sys/devices /system/cpu/cpu0/online which confuses some user-space tools. Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21powerpc: Fix circular dependency between percpu.h and mmu.hMichael Ellerman1-2/+2
commit 0c83b277ada72b585e6a3e52b067669df15bcedb upstream. Recently random.h started including percpu.h (see commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity")), which broke corenet64_smp_defconfig: In file included from /linux/arch/powerpc/include/asm/paca.h:18, from /linux/arch/powerpc/include/asm/percpu.h:13, from /linux/include/linux/random.h:14, from /linux/lib/uuid.c:14: /linux/arch/powerpc/include/asm/mmu.h:139:22: error: unknown type name 'next_tlbcam_idx' 139 | DECLARE_PER_CPU(int, next_tlbcam_idx); This is due to a circular header dependency: asm/mmu.h includes asm/percpu.h, which includes asm/paca.h, which includes asm/mmu.h Which means DECLARE_PER_CPU() isn't defined when mmu.h needs it. We can fix it by moving the include of paca.h below the include of asm-generic/percpu.h. This moves the include of paca.h out of the #ifdef __powerpc64__, but that is OK because paca.h is almost entirely inside #ifdef CONFIG_PPC64 anyway. It also moves the include of paca.h out of the #ifdef CONFIG_SMP, which could possibly break something, but seems to have no ill effects. Fixes: f227e3ec3b5c ("random32: update the net random state on interrupt and activity") Cc: stable@vger.kernel.org # v5.8 Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200804130558.292328-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21ARM: 8992/1: Fix unwind_frame for clang-built kernelsNathan Huckleberry1-0/+24
commit b4d5ec9b39f8b31d98f65bc5577b5d15d93795d7 upstream. Since clang does not push pc and sp in function prologues, the current implementation of unwind_frame does not work. By using the previous frame's lr/fp instead of saved pc/sp we get valid unwinds on clang-built kernels. The bounds check on next frame pointer must be changed as well since there are 8 less bytes between frames. This fixes /proc/<pid>/stack. Link: https://github.com/ClangBuiltLinux/linux/issues/912 Reported-by: Miles Chen <miles.chen@mediatek.com> Tested-by: Miles Chen <miles.chen@mediatek.com> Cc: stable@vger.kernel.org Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Huckleberry <nhuck@google.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21powerpc/vdso: Fix vdso cpu truncationMilton Miller1-1/+1
[ Upstream commit a9f675f950a07d5c1dbcbb97aabac56f5ed085e3 ] The code in vdso_cpu_init that exposes the cpu and numa node to userspace via SPRG_VDSO incorrctly masks the cpu to 12 bits. This means that any kernel running on a box with more than 4096 threads (NR_CPUS advertises a limit of of 8192 cpus) would expose userspace to two cpu contexts running at the same time with the same cpu number. Note: I'm not aware of any distro shipping a kernel with support for more than 4096 threads today, nor of any system image that currently exceeds 4096 threads. Found via code browsing. Fixes: 18ad51dd342a7eb09dbcd059d0b451b616d4dafc ("powerpc: Add VDSO version of getcpu") Signed-off-by: Milton Miller <miltonm@us.ibm.com> Signed-off-by: Anton Blanchard <anton@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200715233704.1352257-1-anton@ozlabs.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21ARM: socfpga: PM: add missing put_device() call in ↵Yu Kuai1-3/+5
socfpga_setup_ocram_self_refresh() [ Upstream commit 3ad7b4e8f89d6bcc9887ca701cf2745a6aedb1a0 ] if of_find_device_by_node() succeed, socfpga_setup_ocram_self_refresh doesn't have a corresponding put_device(). Thus add a jump target to fix the exception handling for this function implementation. Fixes: 44fd8c7d4005 ("ARM: socfpga: support suspend to ram") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Dinh Nguyen <dinguyen@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21ARM: at91: pm: add missing put_device() call in at91_pm_sram_init()yu kuai1-3/+8
[ Upstream commit f87a4f022c44e5b87e842a9f3e644fba87e8385f ] if of_find_device_by_node() succeed, at91_pm_sram_init() doesn't have a corresponding put_device(). Thus add a jump target to fix the exception handling for this function implementation. Fixes: d2e467905596 ("ARM: at91: pm: use the mmio-sram pool to access SRAM") Signed-off-by: yu kuai <yukuai3@huawei.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20200604123301.3905837-1-yukuai3@huawei.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21m68k: mac: Fix IOP status/control register writesFinn Thain1-9/+3
[ Upstream commit 931fc82a6aaf4e2e4a5490addaa6a090d78c24a7 ] When writing values to the IOP status/control register make sure those values do not have any extraneous bits that will clear interrupt flags. To place the SCC IOP into bypass mode would be desirable but this is not achieved by writing IOP_DMAINACTIVE | IOP_RUN | IOP_AUTOINC | IOP_BYPASS to the control register. Drop this ineffective register write. Remove the flawed and unused iop_bypass() function. Make use of the unused iop_stop() function. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Stan Johnson <userm57@yahoo.com> Cc: Joshua Thompson <funaho@jurai.org> Link: https://lore.kernel.org/r/09bcb7359a1719a18b551ee515da3c4c3cf709e6.1590880333.git.fthain@telegraphics.com.au Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21m68k: mac: Don't send IOP message until channel is idleFinn Thain1-6/+3
[ Upstream commit aeb445bf2194d83e12e85bf5c65baaf1f093bd8f ] In the following sequence of calls, iop_do_send() gets called when the "send" channel is not in the IOP_MSG_IDLE state: iop_ism_irq() iop_handle_send() (msg->handler)() iop_send_message() iop_do_send() Avoid this by testing the channel state before calling iop_do_send(). When sending, and iop_send_queue is empty, call iop_do_send() because the channel is idle. If iop_send_queue is not empty, iop_do_send() will get called later by iop_handle_send(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Stan Johnson <userm57@yahoo.com> Cc: Joshua Thompson <funaho@jurai.org> Link: https://lore.kernel.org/r/6d667c39e53865661fa5a48f16829d18ed8abe54.1590880333.git.fthain@telegraphics.com.au Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21ARM: percpu.h: fix build errorGrygorii Strashko1-0/+2
commit aa54ea903abb02303bf55855fb51e3fcee135d70 upstream. Fix build error for the case: defined(CONFIG_SMP) && !defined(CONFIG_CPU_V6) config: keystone_defconfig CC arch/arm/kernel/signal.o In file included from ../include/linux/random.h:14, from ../arch/arm/kernel/signal.c:8: ../arch/arm/include/asm/percpu.h: In function ‘__my_cpu_offset’: ../arch/arm/include/asm/percpu.h:29:34: error: ‘current_stack_pointer’ undeclared (first use in this function); did you mean ‘user_stack_pointer’? : "Q" (*(const unsigned long *)current_stack_pointer)); ^~~~~~~~~~~~~~~~~~~~~ user_stack_pointer Fixes: f227e3ec3b5c ("random32: update the net random state on interrupt and activity") Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21x86/i8259: Use printk_deferred() to prevent deadlockThomas Gleixner1-1/+1
commit bdd65589593edd79b6a12ce86b3b7a7c6dae5208 upstream. 0day reported a possible circular locking dependency: Chain exists of: &irq_desc_lock_class --> console_owner --> &port_lock_key Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&port_lock_key); lock(console_owner); lock(&port_lock_key); lock(&irq_desc_lock_class); The reason for this is a printk() in the i8259 interrupt chip driver which is invoked with the irq descriptor lock held, which reverses the lock operations vs. printk() from arbitrary contexts. Switch the printk() to printk_deferred() to avoid that. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87365abt2v.fsf@nanos.tec.linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21sh: Fix validation of system call numberMichael Karcher1-3/+3
[ Upstream commit 04a8a3d0a73f51c7c2da84f494db7ec1df230e69 ] The slow path for traced system call entries accessed a wrong memory location to get the number of the maximum allowed system call number. Renumber the numbered "local" label for the correct location to avoid collisions with actual local labels. Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de> Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Fixes: f3a8308864f920d2 ("sh: Add a few missing irqflags tracing markers.") Signed-off-by: Rich Felker <dalias@libc.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21ARM: 8986/1: hw_breakpoint: Don't invoke overflow handler on uaccess watchpointsWill Deacon1-5/+22
[ Upstream commit eec13b42d41b0f3339dcf0c4da43734427c68620 ] Unprivileged memory accesses generated by the so-called "translated" instructions (e.g. LDRT) in kernel mode can cause user watchpoints to fire unexpectedly. In such cases, the hw_breakpoint logic will invoke the user overflow handler which will typically raise a SIGTRAP back to the current task. This is futile when returning back to the kernel because (a) the signal won't have been delivered and (b) userspace can't handle the thing anyway. Avoid invoking the user overflow handler for watchpoints triggered by kernel uaccess routines, and instead single-step over the faulting instruction as we would if no overflow handler had been installed. Cc: <stable@vger.kernel.org> Fixes: f81ef4a920c8 ("ARM: 6356/1: hw-breakpoint: add ARM backend for the hw-breakpoint framework") Reported-by: Luis Machado <luis.machado@linaro.org> Tested-by: Luis Machado <luis.machado@linaro.org> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-31parisc: Add atomic64_set_release() define to avoid CPU soft lockupsJohn David Anglin1-0/+2
commit be6577af0cef934ccb036445314072e8cb9217b9 upstream. Stalls are quite frequent with recent kernels. I enabled CONFIG_SOFTLOCKUP_DETECTOR and I caught the following stall: watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [cc1:22803] CPU: 0 PID: 22803 Comm: cc1 Not tainted 5.6.17+ #3 Hardware name: 9000/800/rp3440 IAOQ[0]: d_alloc_parallel+0x384/0x688 IAOQ[1]: d_alloc_parallel+0x388/0x688 RP(r2): d_alloc_parallel+0x134/0x688 Backtrace: [<000000004036974c>] __lookup_slow+0xa4/0x200 [<0000000040369fc8>] walk_component+0x288/0x458 [<000000004036a9a0>] path_lookupat+0x88/0x198 [<000000004036e748>] filename_lookup+0xa0/0x168 [<000000004036e95c>] user_path_at_empty+0x64/0x80 [<000000004035d93c>] vfs_statx+0x104/0x158 [<000000004035dfcc>] __do_sys_lstat64+0x44/0x80 [<000000004035e5a0>] sys_lstat64+0x20/0x38 [<0000000040180054>] syscall_exit+0x0/0x14 The code was stuck in this loop in d_alloc_parallel: 4037d414: 0e 00 10 dc ldd 0(r16),ret0 4037d418: c7 fc 5f ed bb,< ret0,1f,4037d414 <d_alloc_parallel+0x384> 4037d41c: 08 00 02 40 nop This is the inner loop of bit_spin_lock which is called by hlist_bl_unlock in d_alloc_parallel: static inline void bit_spin_lock(int bitnum, unsigned long *addr) { /* * Assuming the lock is uncontended, this never enters * the body of the outer loop. If it is contended, then * within the inner loop a non-atomic test is used to * busywait with less bus contention for a good time to * attempt to acquire the lock bit. */ preempt_disable(); #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) while (unlikely(test_and_set_bit_lock(bitnum, addr))) { preempt_enable(); do { cpu_relax(); } while (test_bit(bitnum, addr)); preempt_disable(); } #endif __acquire(bitlock); } After consideration, I realized that we must be losing bit unlocks. Then, I noticed that we missed defining atomic64_set_release(). Adding this define fixes the stalls in bit operations. Signed-off-by: Dave Anglin <dave.anglin@bell.net> Cc: stable@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-31x86: math-emu: Fix up 'cmp' insn for clang iasArnd Bergmann1-1/+1
[ Upstream commit 81e96851ea32deb2c921c870eecabf335f598aeb ] The clang integrated assembler requires the 'cmp' instruction to have a length prefix here: arch/x86/math-emu/wm_sqrt.S:212:2: error: ambiguous instructions require an explicit suffix (could be 'cmpb', 'cmpw', or 'cmpl') cmp $0xffffffff,-24(%ebp) ^ Make this a 32-bit comparison, which it was clearly meant to be. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lkml.kernel.org/r/20200527135352.1198078-1-arnd@arndb.de Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-31arm64: Use test_tsk_thread_flag() for checking TIF_SINGLESTEPWill Deacon1-2/+2
[ Upstream commit 5afc78551bf5d53279036e0bf63314e35631d79f ] Rather than open-code test_tsk_thread_flag() at each callsite, simply replace the couple of offenders with calls to test_tsk_thread_flag() directly. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-31x86/fpu: Disable bottom halves while loading FPU registersSebastian Andrzej Siewior1-2/+2
[ Upstream commit 68239654acafe6aad5a3c1dc7237e60accfebc03 ] The sequence fpu->initialized = 1; /* step A */ preempt_disable(); /* step B */ fpu__restore(fpu); preempt_enable(); in __fpu__restore_sig() is racy in regard to a context switch. For 32bit frames, __fpu__restore_sig() prepares the FPU state within fpu->state. To ensure that a context switch (switch_fpu_prepare() in particular) does not modify fpu->state it uses fpu__drop() which sets fpu->initialized to 0. After fpu->initialized is cleared, the CPU's FPU state is not saved to fpu->state during a context switch. The new state is loaded via fpu__restore(). It gets loaded into fpu->state from userland and ensured it is sane. fpu->initialized is then set to 1 in order to avoid fpu__initialize() doing anything (overwrite the new state) which is part of fpu__restore(). A context switch between step A and B above would save CPU's current FPU registers to fpu->state and overwrite the newly prepared state. This looks like a tiny race window but the Kernel Test Robot reported this back in 2016 while we had lazy FPU support. Borislav Petkov made the link between that report and another patch that has been posted. Since the removal of the lazy FPU support, this race goes unnoticed because the warning has been removed. Disable bottom halves around the restore sequence to avoid the race. BH need to be disabled because BH is allowed to run (even with preemption disabled) and might invoke kernel_fpu_begin() by doing IPsec. [ bp: massage commit message a bit. ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: stable@vger.kernel.org Cc: x86-ml <x86@kernel.org> Link: http://lkml.kernel.org/r/20181120102635.ddv3fvavxajjlfqk@linutronix.de Link: https://lkml.kernel.org/r/20160226074940.GA28911@pd.tnic Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-31xtensa: update *pos in cpuinfo_op.nextMax Filippov1-1/+2
[ Upstream commit 0d5ab144429e8bd80889b856a44d56ab4a5cd59b ] Increment *pos in the cpuinfo_op.next to fix the following warning triggered by cat /proc/cpuinfo: seq_file: buggy .next function c_next did not update position index Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-31xtensa: fix __sync_fetch_and_{and,or}_4 declarationsMax Filippov1-2/+2
[ Upstream commit 73f9941306d5ce030f3ffc7db425c7b2a798cf8e ] Building xtensa kernel with gcc-10 produces the following warnings: arch/xtensa/kernel/xtensa_ksyms.c:90:15: warning: conflicting types for built-in function ‘__sync_fetch_and_and_4’; expected ‘unsigned int(volatile void *, unsigned int)’ [-Wbuiltin-declaration-mismatch] arch/xtensa/kernel/xtensa_ksyms.c:96:15: warning: conflicting types for built-in function ‘__sync_fetch_and_or_4’; expected ‘unsigned int(volatile void *, unsigned int)’ [-Wbuiltin-declaration-mismatch] Fix declarations of these functions to avoid the warning. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-22MIPS: Fix build for LTS kernel caused by backporting lpj adjustmentHuacai Chen1-9/+4
Commit ed26aacfb5f71eecb20a ("mips: Add udelay lpj numbers adjustment") has backported to 4.4~5.4, but the "struct cpufreq_freqs" (and also the cpufreq notifier machanism) of 4.4~4.19 are different from the upstream kernel. These differences cause build errors, and this patch can fix the build. Cc: Serge Semin <Sergey.Semin@baikalelectronics.ru> Cc: Stable <stable@vger.kernel.org> # 4.4/4.9/4.14/4.19 Signed-off-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22ARC: elf: use right ELF_ARCHVineet Gupta1-1/+1
commit b7faf971081a4e56147f082234bfff55135305cb upstream. Cc: <stable@vger.kernel.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22ARC: entry: fix potential EFA clobber when TIF_SYSCALL_TRACEVineet Gupta1-11/+5
commit 00fdec98d9881bf5173af09aebd353ab3b9ac729 upstream. Trap handler for syscall tracing reads EFA (Exception Fault Address), in case strace wants PC of trap instruction (EFA is not part of pt_regs as of current code). However this EFA read is racy as it happens after dropping to pure kernel mode (re-enabling interrupts). A taken interrupt could context-switch, trigger a different task's trap, clobbering EFA for this execution context. Fix this by reading EFA early, before re-enabling interrupts. A slight side benefit is de-duplication of FAKE_RET_FROM_EXCPN in trap handler. The trap handler is common to both ARCompact and ARCv2 builds too. This just came out of code rework/review and no real problem was reported but is clearly a potential problem specially for strace. Cc: <stable@vger.kernel.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22KVM: x86: bit 8 of non-leaf PDPEs is not reservedPaolo Bonzini1-1/+1
commit 5ecad245de2ae23dc4e2dbece92f8ccfbaed2fa7 upstream. Bit 8 would be the "global" bit, which does not quite make sense for non-leaf page table entries. Intel ignores it; AMD ignores it in PDEs and PDPEs, but reserves it in PML4Es. Probably, earlier versions of the AMD manual documented it as reserved in PDPEs as well, and that behavior made it into KVM as well as kvm-unit-tests; fix it. Cc: stable@vger.kernel.org Reported-by: Nadav Amit <namit@vmware.com> Fixes: a0c0feb57992 ("KVM: x86: reserve bit 8 of non-leaf PDPEs and PML4Es in 64-bit mode on AMD", 2014-09-03) Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22arm64: kgdb: Fix single-step exception handling oopsWei Li1-1/+1
[ Upstream commit 8523c006264df65aac7d77284cc69aac46a6f842 ] After entering kdb due to breakpoint, when we execute 'ss' or 'go' (will delay installing breakpoints, do single-step first), it won't work correctly, and it will enter kdb due to oops. It's because the reason gotten in kdb_stub() is not as expected, and it seems that the ex_vector for single-step should be 0, like what arch powerpc/sh/parisc has implemented. Before the patch: Entering kdb (current=0xffff8000119e2dc0, pid 0) on processor 0 due to Keyboard Entry [0]kdb> bp printk Instruction(i) BP #0 at 0xffff8000101486cc (printk) is enabled addr at ffff8000101486cc, hardtype=0 installed=0 [0]kdb> g / # echo h > /proc/sysrq-trigger Entering kdb (current=0xffff0000fa878040, pid 266) on processor 3 due to Breakpoint @ 0xffff8000101486cc [3]kdb> ss Entering kdb (current=0xffff0000fa878040, pid 266) on processor 3 Oops: (null) due to oops @ 0xffff800010082ab8 CPU: 3 PID: 266 Comm: sh Not tainted 5.7.0-rc4-13839-gf0e5ad491718 #6 Hardware name: linux,dummy-virt (DT) pstate: 00000085 (nzcv daIf -PAN -UAO) pc : el1_irq+0x78/0x180 lr : __handle_sysrq+0x80/0x190 sp : ffff800015003bf0 x29: ffff800015003d20 x28: ffff0000fa878040 x27: 0000000000000000 x26: ffff80001126b1f0 x25: ffff800011b6a0d8 x24: 0000000000000000 x23: 0000000080200005 x22: ffff8000101486cc x21: ffff800015003d30 x20: 0000ffffffffffff x19: ffff8000119f2000 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 x8 : ffff800015003e50 x7 : 0000000000000002 x6 : 00000000380b9990 x5 : ffff8000106e99e8 x4 : ffff0000fadd83c0 x3 : 0000ffffffffffff x2 : ffff800011b6a0d8 x1 : ffff800011b6a000 x0 : ffff80001130c9d8 Call trace: el1_irq+0x78/0x180 printk+0x0/0x84 write_sysrq_trigger+0xb0/0x118 proc_reg_write+0xb4/0xe0 __vfs_write+0x18/0x40 vfs_write+0xb0/0x1b8 ksys_write+0x64/0xf0 __arm64_sys_write+0x14/0x20 el0_svc_common.constprop.2+0xb0/0x168 do_el0_svc+0x20/0x98 el0_sync_handler+0xec/0x1a8 el0_sync+0x140/0x180 [3]kdb> After the patch: Entering kdb (current=0xffff8000119e2dc0, pid 0) on processor 0 due to Keyboard Entry [0]kdb> bp printk Instruction(i) BP #0 at 0xffff8000101486cc (printk) is enabled addr at ffff8000101486cc, hardtype=0 installed=0 [0]kdb> g / # echo h > /proc/sysrq-trigger Entering kdb (current=0xffff0000fa852bc0, pid 268) on processor 0 due to Breakpoint @ 0xffff8000101486cc [0]kdb> g Entering kdb (current=0xffff0000fa852bc0, pid 268) on processor 0 due to Breakpoint @ 0xffff8000101486cc [0]kdb> ss Entering kdb (current=0xffff0000fa852bc0, pid 268) on processor 0 due to SS trap @ 0xffff800010082ab8 [0]kdb> Fixes: 44679a4f142b ("arm64: KGDB: Add step debugging support") Signed-off-by: Wei Li <liwei391@huawei.com> Tested-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20200509214159.19680-2-liwei391@huawei.com Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-22KVM: s390: reduce number of IO pins to 1Christian Borntraeger1-4/+4
[ Upstream commit 774911290c589e98e3638e73b24b0a4d4530e97c ] The current number of KVM_IRQCHIP_NUM_PINS results in an order 3 allocation (32kb) for each guest start/restart. This can result in OOM killer activity even with free swap when the memory is fragmented enough: kernel: qemu-system-s39 invoked oom-killer: gfp_mask=0x440dc0(GFP_KERNEL_ACCOUNT|__GFP_COMP|__GFP_ZERO), order=3, oom_score_adj=0 kernel: CPU: 1 PID: 357274 Comm: qemu-system-s39 Kdump: loaded Not tainted 5.4.0-29-generic #33-Ubuntu kernel: Hardware name: IBM 8562 T02 Z06 (LPAR) kernel: Call Trace: kernel: ([<00000001f848fe2a>] show_stack+0x7a/0xc0) kernel: [<00000001f8d3437a>] dump_stack+0x8a/0xc0 kernel: [<00000001f8687032>] dump_header+0x62/0x258 kernel: [<00000001f8686122>] oom_kill_process+0x172/0x180 kernel: [<00000001f8686abe>] out_of_memory+0xee/0x580 kernel: [<00000001f86e66b8>] __alloc_pages_slowpath+0xd18/0xe90 kernel: [<00000001f86e6ad4>] __alloc_pages_nodemask+0x2a4/0x320 kernel: [<00000001f86b1ab4>] kmalloc_order+0x34/0xb0 kernel: [<00000001f86b1b62>] kmalloc_order_trace+0x32/0xe0 kernel: [<00000001f84bb806>] kvm_set_irq_routing+0xa6/0x2e0 kernel: [<00000001f84c99a4>] kvm_arch_vm_ioctl+0x544/0x9e0 kernel: [<00000001f84b8936>] kvm_vm_ioctl+0x396/0x760 kernel: [<00000001f875df66>] do_vfs_ioctl+0x376/0x690 kernel: [<00000001f875e304>] ksys_ioctl+0x84/0xb0 kernel: [<00000001f875e39a>] __s390x_sys_ioctl+0x2a/0x40 kernel: [<00000001f8d55424>] system_call+0xd8/0x2c8 As far as I can tell s390x does not use the iopins as we bail our for anything other than KVM_IRQ_ROUTING_S390_ADAPTER and the chip/pin is only used for KVM_IRQ_ROUTING_IRQCHIP. So let us use a small number to reduce the memory footprint. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200617083620.5409-1-borntraeger@de.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-09MIPS: Add missing EHB in mtc0 -> mfc0 sequence for DSPenHauke Mehrtens1-0/+1
commit fcec538ef8cca0ad0b84432235dccd9059c8e6f8 upstream. This resolves the hazard between the mtc0 in the change_c0_status() and the mfc0 in configure_exception_vector(). Without resolving this hazard configure_exception_vector() could read an old value and would restore this old value again. This would revert the changes change_c0_status() did. I checked this by printing out the read_c0_status() at the end of per_cpu_trap_init() and the ST0_MX is not set without this patch. The hazard is documented in the MIPS Architecture Reference Manual Vol. III: MIPS32/microMIPS32 Privileged Resource Architecture (MD00088), rev 6.03 table 8.1 which includes: Producer | Consumer | Hazard ----------|----------|---------------------------- mtc0 | mfc0 | any coprocessor 0 register I saw this hazard on an Atheros AR9344 rev 2 SoC with a MIPS 74Kc CPU. There the change_c0_status() function would activate the DSPen by setting ST0_MX in the c0_status register. This was reverted and then the system got a DSP exception when the DSP registers were saved in save_dsp() in the first process switch. The crash looks like this: [ 0.089999] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) [ 0.097796] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) [ 0.107070] Kernel panic - not syncing: Unexpected DSP exception [ 0.113470] Rebooting in 1 seconds.. We saw this problem in OpenWrt only on the MIPS 74Kc based Atheros SoCs, not on the 24Kc based SoCs. We only saw it with kernel 5.4 not with kernel 4.19, in addition we had to use GCC 8.4 or 9.X, with GCC 8.3 it did not happen. In the kernel I bisected this problem to commit 9012d011660e ("compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING"), but when this was reverted it also happened after commit 172dcd935c34b ("MIPS: Always allocate exception vector for MIPSr2+"). Commit 0b24cae4d535 ("MIPS: Add missing EHB in mtc0 -> mfc0 sequence.") does similar changes to a different file. I am not sure if there are more places affected by this problem. Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de> Cc: <stable@vger.kernel.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30arm64: perf: Report the PC value in REGS_ABI_32 modeJiping Ma1-3/+22
commit 8dfe804a4031ca6ba3a3efb2048534249b64f3a5 upstream. A 32-bit perf querying the registers of a compat task using REGS_ABI_32 will receive zeroes from w15, when it expects to find the PC. Return the PC value for register dwarf register 15 when returning register values for a compat task to perf. Cc: <stable@vger.kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Jiping Ma <jiping.ma2@windriver.com> Link: https://lore.kernel.org/r/1589165527-188401-1-git-send-email-jiping.ma2@windriver.com [will: Shuffled code and added a comment] Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30KVM: X86: Fix MSR range of APIC registers in X2APIC modeXiaoyao Li1-2/+2
commit bf10bd0be53282183f374af23577b18b5fbf7801 upstream. Only MSR address range 0x800 through 0x8ff is architecturally reserved and dedicated for accessing APIC registers in x2APIC mode. Fixes: 0105d1a52640 ("KVM: x2apic interface to lapic") Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> Message-Id: <20200616073307.16440-1-xiaoyao.li@intel.com> Cc: stable@vger.kernel.org Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30ARM: imx5: add missing put_device() call in imx_suspend_alloc_ocram()yu kuai1-2/+4
[ Upstream commit 586745f1598ccf71b0a5a6df2222dee0a865954e ] if of_find_device_by_node() succeed, imx_suspend_alloc_ocram() doesn't have a corresponding put_device(). Thus add a jump target to fix the exception handling for this function implementation. Fixes: 1579c7b9fe01 ("ARM: imx53: Set DDR pins to high impedance when in suspend to RAM.") Signed-off-by: yu kuai <yukuai3@huawei.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30fix a braino in "sparc32: fix register window handling in genregs32_[gs]et()"Al Viro1-2/+7
[ Upstream commit 9d964e1b82d8182184153b70174f445ea616f053 ] lost npc in PTRACE_SETREGSET, breaking PTRACE_SETREGS as well Fixes: cf51e129b968 "sparc32: fix register window handling in genregs32_[gs]et()" Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30kretprobe: Prevent triggering kretprobe from within kprobe_flush_taskJiri Olsa1-13/+3
[ Upstream commit 9b38cc704e844e41d9cf74e647bff1d249512cb3 ] Ziqian reported lockup when adding retprobe on _raw_spin_lock_irqsave. My test was also able to trigger lockdep output: ============================================ WARNING: possible recursive locking detected 5.6.0-rc6+ #6 Not tainted -------------------------------------------- sched-messaging/2767 is trying to acquire lock: ffffffff9a492798 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_hash_lock+0x52/0xa0 but task is already holding lock: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(kretprobe_table_locks[i].lock)); lock(&(kretprobe_table_locks[i].lock)); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by sched-messaging/2767: #0: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50 stack backtrace: CPU: 3 PID: 2767 Comm: sched-messaging Not tainted 5.6.0-rc6+ #6 Call Trace: dump_stack+0x96/0xe0 __lock_acquire.cold.57+0x173/0x2b7 ? native_queued_spin_lock_slowpath+0x42b/0x9e0 ? lockdep_hardirqs_on+0x590/0x590 ? __lock_acquire+0xf63/0x4030 lock_acquire+0x15a/0x3d0 ? kretprobe_hash_lock+0x52/0xa0 _raw_spin_lock_irqsave+0x36/0x70 ? kretprobe_hash_lock+0x52/0xa0 kretprobe_hash_lock+0x52/0xa0 trampoline_handler+0xf8/0x940 ? kprobe_fault_handler+0x380/0x380 ? find_held_lock+0x3a/0x1c0 kretprobe_trampoline+0x25/0x50 ? lock_acquired+0x392/0xbc0 ? _raw_spin_lock_irqsave+0x50/0x70 ? __get_valid_kprobe+0x1f0/0x1f0 ? _raw_spin_unlock_irqrestore+0x3b/0x40 ? finish_task_switch+0x4b9/0x6d0 ? __switch_to_asm+0x34/0x70 ? __switch_to_asm+0x40/0x70 The code within the kretprobe handler checks for probe reentrancy, so we won't trigger any _raw_spin_lock_irqsave probe in there. The problem is in outside kprobe_flush_task, where we call: kprobe_flush_task kretprobe_table_lock raw_spin_lock_irqsave _raw_spin_lock_irqsave where _raw_spin_lock_irqsave triggers the kretprobe and installs kretprobe_trampoline handler on _raw_spin_lock_irqsave return. The kretprobe_trampoline handler is then executed with already locked kretprobe_table_locks, and first thing it does is to lock kretprobe_table_locks ;-) the whole lockup path like: kprobe_flush_task kretprobe_table_lock raw_spin_lock_irqsave _raw_spin_lock_irqsave ---> probe triggered, kretprobe_trampoline installed ---> kretprobe_table_locks locked kretprobe_trampoline trampoline_handler kretprobe_hash_lock(current, &head, &flags); <--- deadlock Adding kprobe_busy_begin/end helpers that mark code with fake probe installed to prevent triggering of another kprobe within this code. Using these helpers in kprobe_flush_task, so the probe recursion protection check is hit and the probe is never set to prevent above lockup. Link: http://lkml.kernel.org/r/158927059835.27680.7011202830041561604.stgit@devnote2 Fixes: ef53d9c5e4da ("kprobes: improve kretprobe scalability with hashed locking") Cc: Ingo Molnar <mingo@kernel.org> Cc: "Gustavo A . R . Silva" <gustavoars@kernel.org> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Reported-by: "Ziqian SUN (Zamir)" <zsun@redhat.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30x86/kprobes: Avoid kretprobe recursion bugMasami Hiramatsu1-2/+20
[ Upstream commit b191fa96ea6dc00d331dcc28c1f7db5e075693a0 ] Avoid kretprobe recursion loop bg by setting a dummy kprobes to current_kprobe per-CPU variable. This bug has been introduced with the asm-coded trampoline code, since previously it used another kprobe for hooking the function return placeholder (which only has a nop) and trampoline handler was called from that kprobe. This revives the old lost kprobe again. With this fix, we don't see deadlock anymore. And you can see that all inner-called kretprobe are skipped. event_1 235 0 event_2 19375 19612 The 1st column is recorded count and the 2nd is missed count. Above shows (event_1 rec) + (event_2 rec) ~= (event_2 missed) (some difference are here because the counter is racy) Reported-by: Andrea Righi <righi.andrea@gmail.com> Tested-by: Andrea Righi <righi.andrea@gmail.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Fixes: c9becf58d935 ("[PATCH] kretprobe: kretprobe-booster") Link: http://lkml.kernel.org/r/155094064889.6137.972160690963039.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30powerpc/kprobes: Fixes for kprobe_lookup_name() on BENaveen N. Rao1-1/+2
[ Upstream commit 30176466e36aadba01e1a630cf42397a3438efa4 ] Fix two issues with kprobes.h on BE which were exposed with the optprobes work: - one, having to do with a missing include for linux/module.h for MODULE_NAME_LEN -- this didn't show up previously since the only users of kprobe_lookup_name were in kprobes.c, which included linux/module.h through other headers, and - two, with a missing const qualifier for a local variable which ends up referring a string literal. Again, this is unique to how kprobe_lookup_name is being invoked in optprobes.c Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30sparc64: fix misuses of access_process_vm() in genregs32_[sg]et()Al Viro1-11/+2
[ Upstream commit 142cd25293f6a7ecbdff4fb0af17de6438d46433 ] We do need access_process_vm() to access the target's reg_window. However, access to caller's memory (storing the result in genregs32_get(), fetching the new values in case of genregs32_set()) should be done by normal uaccess primitives. Fixes: ad4f95764040 ([SPARC64]: Fix user accesses in regset code.) Cc: stable@kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30openrisc: Fix issue with argument clobbering for clone/forkStafford Horne1-2/+2
[ Upstream commit 6bd140e14d9aaa734ec37985b8b20a96c0ece948 ] Working on the OpenRISC glibc port I found that sometimes clone was working strange. That the tls data argument sent in r7 was always wrong. Further investigation revealed that the arguments were getting clobbered in the entry code. This patch removes the code that writes to the argument registers. This was likely due to some old code hanging around. This patch fixes this up for clone and fork. This fork clobber is harmless but also useless so remove. Signed-off-by: Stafford Horne <shorne@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30powerpc/ps3: Fix kexec shutdown hangGeoff Levand1-10/+12
[ Upstream commit 126554465d93b10662742128918a5fc338cda4aa ] The ps3_mm_region_destroy() and ps3_mm_vas_destroy() routines are called very late in the shutdown via kexec's mmu_cleanup_all routine. By the time mmu_cleanup_all runs it is too late to use udbg_printf, and calling it will cause PS3 systems to hang. Remove all debugging statements from ps3_mm_region_destroy() and ps3_mm_vas_destroy() and replace any error reporting with calls to lv1_panic. With this change builds with 'DEBUG' defined will not cause kexec reboots to hang, and builds with 'DEBUG' defined or not will end in lv1_panic if an error is encountered. Signed-off-by: Geoff Levand <geoff@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7325c4af2b4c989c19d6a26b90b1fec9c0615ddf.1589049250.git.geoff@infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30powerpc/pseries/ras: Fix FWNMI_VALID off by oneNicholas Piggin1-2/+3
[ Upstream commit deb70f7a35a22dffa55b2c3aac71bc6fb0f486ce ] This was discovered developing qemu fwnmi sreset support. This off-by-one bug means the last 16 bytes of the rtas area can not be used for a 16 byte save area. It's not a serious bug, and QEMU implementation has to retain a workaround for old kernels, but it's good to tighten it. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> Link: https://lore.kernel.org/r/20200508043408.886394-7-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30powerpc/crashkernel: Take "mem=" option into accountPingfan Liu1-3/+5
[ Upstream commit be5470e0c285a68dc3afdea965032f5ddc8269d7 ] 'mem=" option is an easy way to put high pressure on memory during some test. Hence after applying the memory limit, instead of total mem, the actual usable memory should be considered when reserving mem for crashkernel. Otherwise the boot up may experience OOM issue. E.g. it would reserve 4G prior to the change and 512M afterward, if passing crashkernel="2G-4G:384M,4G-16G:512M,16G-64G:1G,64G-128G:2G,128G-:4G", and mem=5G on a 256G machine. This issue is powerpc specific because it puts higher priority on fadump and kdump reservation than on "mem=". Referring the following code: if (fadump_reserve_mem() == 0) reserve_crashkernel(); ... /* Ensure that total memory size is page-aligned. */ limit = ALIGN(memory_limit ?: memblock_phys_mem_size(), PAGE_SIZE); memblock_enforce_memory_limit(limit); While on other arches, the effect of "mem=" takes a higher priority and pass through memblock_phys_mem_size() before calling reserve_crashkernel(). Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Reviewed-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1585749644-4148-1-git-send-email-kernelfans@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30s390: fix syscall_get_error for compat processesDmitry V. Levin1-1/+11
commit b3583fca5fb654af2cfc1c08259abb9728272538 upstream. If both the tracer and the tracee are compat processes, and gprs[2] is assigned a value by __poke_user_compat, then the higher 32 bits of gprs[2] are cleared, IS_ERR_VALUE() always returns false, and syscall_get_error() always returns 0. Fix the implementation by sign-extending the value for compat processes the same way as x86 implementation does. The bug was exposed to user space by commit 201766a20e30f ("ptrace: add PTRACE_GET_SYSCALL_INFO request") and detected by strace test suite. This change fixes strace syscall tampering on s390. Link: https://lkml.kernel.org/r/20200602180051.GA2427@altlinux.org Fixes: 753c4dd6a2fa2 ("[S390] ptrace changes") Cc: Elvira Khabirova <lineprinter@altlinux.org> Cc: stable@vger.kernel.org # v2.6.28+ Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-20ARM: tegra: Correct PL310 Auxiliary Control Register initializationDmitry Osipenko1-2/+2
commit 35509737c8f958944e059d501255a0bf18361ba0 upstream. The PL310 Auxiliary Control Register shouldn't have the "Full line of zero" optimization bit being set before L2 cache is enabled. The L2X0 driver takes care of enabling the optimization by itself. This patch fixes a noisy error message on Tegra20 and Tegra30 telling that cache optimization is erroneously enabled without enabling it for the CPU: L2C-310: enabling full line of zeros but not enabled in Cortex-A9 Cc: <stable@vger.kernel.org> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Tested-by: Nicolas Chauvet <kwizart@gmail.com> Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-20sparc32: fix register window handling in genregs32_[gs]et()Al Viro1-130/+98
commit cf51e129b96847f969bfb8af1ee1516a01a70b39 upstream. It needs access_process_vm() if the traced process does not share mm with the caller. Solution is similar to what sparc64 does. Note that genregs32_set() is only ever called with pos being 0 or 32 * sizeof(u32) (the latter - as part of PTRACE_SETREGS handling). Cc: stable@kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-20MIPS: Fix IRQ tracing when call handle_fpe() and handle_msa_fpe()YuanJunQing1-3/+3
[ Upstream commit 31e1b3efa802f97a17628dde280006c4cee4ce5e ] Register "a1" is unsaved in this function, when CONFIG_TRACE_IRQFLAGS is enabled, the TRACE_IRQS_OFF macro will call trace_hardirqs_off(), and this may change register "a1". The changed register "a1" as argument will be send to do_fpe() and do_msa_fpe(). Signed-off-by: YuanJunQing <yuanjunqing66@163.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-20m68k: mac: Don't call via_flush_cache() on Mac IIfxFinn Thain3-20/+8
[ Upstream commit bcc44f6b74106b31f0b0408b70305a40360d63b7 ] There is no VIA2 chip on the Mac IIfx, so don't call via_flush_cache(). This avoids a boot crash which appeared in v5.4. printk: console [ttyS0] enabled printk: bootconsole [debug0] disabled printk: bootconsole [debug0] disabled Calibrating delay loop... 9.61 BogoMIPS (lpj=48064) pid_max: default: 32768 minimum: 301 Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) devtmpfs: initialized random: get_random_u32 called from bucket_table_alloc.isra.27+0x68/0x194 with crng_init=0 clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns futex hash table entries: 256 (order: -1, 3072 bytes, linear) NET: Registered protocol family 16 Data read fault at 0x00000000 in Super Data (pc=0x8a6a) BAD KERNEL BUSERR Oops: 00000000 Modules linked in: PC: [<00008a6a>] via_flush_cache+0x12/0x2c SR: 2700 SP: 01c1fe3c a2: 01c24000 d0: 00001119 d1: 0000000c d2: 00012000 d3: 0000000f d4: 01c06840 d5: 00033b92 a0: 00000000 a1: 00000000 Process swapper (pid: 1, task=01c24000) Frame format=B ssw=0755 isc=0200 isb=fff7 daddr=00000000 dobuf=01c1fed0 baddr=00008a6e dibuf=0000004e ver=f Stack from 01c1fec4: 01c1fed0 00007d7e 00010080 01c1fedc 0000792e 00000001 01c1fef4 00006b40 01c80000 00040000 00000006 00000003 01c1ff1c 004a545e 004ff200 00040000 00000000 00000003 01c06840 00033b92 004a5410 004b6c88 01c1ff84 000021e2 00000073 00000003 01c06840 00033b92 0038507a 004bb094 004b6ca8 004b6c88 004b6ca4 004b6c88 000021ae 00020002 00000000 01c0685d 00000000 01c1ffb4 0049f938 00409c85 01c06840 0045bd40 00000073 00000002 00000002 00000000 Call Trace: [<00007d7e>] mac_cache_card_flush+0x12/0x1c [<00010080>] fix_dnrm+0x2/0x18 [<0000792e>] cache_push+0x46/0x5a [<00006b40>] arch_dma_prep_coherent+0x60/0x6e [<00040000>] switched_to_dl+0x76/0xd0 [<004a545e>] dma_atomic_pool_init+0x4e/0x188 [<00040000>] switched_to_dl+0x76/0xd0 [<00033b92>] parse_args+0x0/0x370 [<004a5410>] dma_atomic_pool_init+0x0/0x188 [<000021e2>] do_one_initcall+0x34/0x1be [<00033b92>] parse_args+0x0/0x370 [<0038507a>] strcpy+0x0/0x1e [<000021ae>] do_one_initcall+0x0/0x1be [<00020002>] do_proc_dointvec_conv+0x54/0x74 [<0049f938>] kernel_init_freeable+0x126/0x190 [<0049f94c>] kernel_init_freeable+0x13a/0x190 [<004a5410>] dma_atomic_pool_init+0x0/0x188 [<00041798>] complete+0x0/0x3c [<000b9b0c>] kfree+0x0/0x20a [<0038df98>] schedule+0x0/0xd0 [<0038d604>] kernel_init+0x0/0xda [<0038d610>] kernel_init+0xc/0xda [<0038d604>] kernel_init+0x0/0xda [<00002d38>] ret_from_kernel_thread+0xc/0x14 Code: 0000 2079 0048 10da 2279 0048 10c8 d3c8 <1011> 0200 fff7 1280 d1f9 0048 10c8 1010 0000 0008 1080 4e5e 4e75 4e56 0000 2039 Disabling lock debugging due to kernel taint Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b Thanks to Stan Johnson for capturing the console log and running git bisect. Git bisect said commit 8e3a68fb55e0 ("dma-mapping: make dma_atomic_pool_init self-contained") is the first "bad" commit. I don't know why. Perhaps mach_l2_flush first became reachable with that commit. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-and-tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Cc: Joshua Thompson <funaho@jurai.org> Link: https://lore.kernel.org/r/b8bbeef197d6b3898e82ed0d231ad08f575a4b34.1589949122.git.fthain@telegraphics.com.au Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-20x86/mm: Stop printing BRK addressesArvind Sankar1-2/+0
[ Upstream commit 67d631b7c05eff955ccff4139327f0f92a5117e5 ] This currently leaks kernel physical addresses into userspace. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Dave Hansen <dave.hansen@intel.com> Link: https://lkml.kernel.org/r/20200229231120.1147527-1-nivedita@alum.mit.edu Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-20mips: Add udelay lpj numbers adjustmentSerge Semin1-0/+70
[ Upstream commit ed26aacfb5f71eecb20a51c4467da440cb719d66 ] Loops-per-jiffies is a special number which represents a number of noop-loop cycles per CPU-scheduler quantum - jiffies. As you understand aside from CPU-specific implementation it depends on the CPU frequency. So when a platform has the CPU frequency fixed, we have no problem and the current udelay interface will work just fine. But as soon as CPU-freq driver is enabled and the cores frequency changes, we'll end up with distorted udelay's. In order to fix this we have to accordinly adjust the per-CPU udelay_val (the same as the global loops_per_jiffy) number. This can be done in the CPU-freq transition event handler. We subscribe to that event in the MIPS arch time-inititalization method. Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Paul Burton <paulburton@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: devicetree@vger.kernel.org Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org>