kernel/linux.git/arch, branch v4.4.275

arm: kprobes: Allow to handle reentered kprobe on single-stepping

2021-07-11T10:45:27+00:00

commit f3fbd7ec62dec1528fb8044034e2885f2b257941 upstream. This is arm port of commit 6a5022a56ac3 ("kprobes/x86: Allow to handle reentered kprobe on single-stepping") Since the FIQ handlers can interrupt in the single stepping (or preparing the single stepping, do_debug etc.), we should consider a kprobe is hit in the NMI handler. Even in that case, the kprobe is allowed to be reentered as same as the kprobes hit in kprobe handlers (KPROBE_HIT_ACTIVE or KPROBE_HIT_SSDONE). The real issue will happen when a kprobe hit while another reentered kprobe is processing (KPROBE_REENTER), because we already consumed a saved-area for the previous kprobe. Signed-off-by: Masami Hiramatsu Signed-off-by: Jon Medhurst Fixes: 24ba613c9d6c ("ARM kprobes: core code") Cc: stable@vger.kernel.org #v2.6.25~v4.11 Signed-off-by: huangshaobo Signed-off-by: Greg Kroah-Hartman

ARM: 9081/1: fix gcc-10 thumb2-kernel regression

2021-06-30T12:49:36+00:00

commit dad7b9896a5dbac5da8275d5a6147c65c81fb5f2 upstream. When building the kernel wtih gcc-10 or higher using the CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE=y flag, the compiler picks a slightly different set of registers for the inline assembly in cpu_init() that subsequently results in a corrupt kernel stack as well as remaining in FIQ mode. If a banked register is used for the last argument, the wrong version of that register gets loaded into CPSR_c. When building in Arm mode, the arguments are passed as immediate values and the bug cannot happen. This got introduced when Daniel reworked the FIQ handling and was technically always broken, but happened to work with both clang and gcc before gcc-10 as long as they picked one of the lower registers. This is probably an indication that still very few people build the kernel in Thumb2 mode. Marek pointed out the problem on IRC, Arnd narrowed it down to this inline assembly and Russell pinpointed the exact bug. Change the constraints to force the final mode switch to use a non-banked register for the argument to ensure that the correct constant gets loaded. Another alternative would be to always use registers for the constant arguments to avoid the #ifdef that has now become more complex. Cc: # v3.18+ Cc: Daniel Thompson Reported-by: Marek Vasut Acked-by: Ard Biesheuvel Fixes: c0e7f7ee717e ("ARM: 8150/3: fiq: Replace default FIQ handler") Signed-off-by: Arnd Bergmann Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman

x86/fpu: Reset state for all signal restore failures

2021-06-30T12:49:36+00:00

commit efa165504943f2128d50f63de0c02faf6dcceb0d upstream. If access_ok() or fpregs_soft_set() fails in __fpu__restore_sig() then the function just returns but does not clear the FPU state as it does for all other fatal failures. Clear the FPU state for these failures as well. Fixes: 72a671ced66d ("x86, fpu: Unify signal handling code paths for x86 and x86_64 kernels") Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/87mtryyhhz.ffs@nanos.tec.linutronix.de Signed-off-by: Greg Kroah-Hartman

ARM: OMAP2+: Fix build warning when mmc_omap is not built

2021-06-30T12:49:30+00:00

[ Upstream commit 040ab72ee10ea88e1883ad143b3e2b77596abc31 ] GCC reports the following warning with W=1: arch/arm/mach-omap2/board-n8x0.c:325:19: warning: variable 'index' set but not used [-Wunused-but-set-variable] 325 | int bit, *openp, index; | ^~~~~ Fix this by moving CONFIG_MMC_OMAP to cover the rest codes in the n8x0_mmc_callback(). Signed-off-by: Yongqiang Liu Signed-off-by: Tony Lindgren Signed-off-by: Sasha Levin

powerpc/fsl: set fsl,i2c-erratum-a004447 flag for P1010 i2c controllers

2021-06-16T09:34:52+00:00

[ Upstream commit 19ae697a1e4edf1d755b413e3aa38da65e2db23b ] The i2c controllers on the P1010 have an erratum where the documented scheme for i2c bus recovery will not work (A-004447). A different mechanism is needed which is documented in the P1010 Chip Errata Rev L. Signed-off-by: Chris Packham Acked-by: Michael Ellerman Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin

powerpc/fsl: set fsl,i2c-erratum-a004447 flag for P2041 i2c controllers

2021-06-16T09:34:52+00:00

[ Upstream commit 7adc7b225cddcfd0f346d10144fd7a3d3d9f9ea7 ] The i2c controllers on the P2040/P2041 have an erratum where the documented scheme for i2c bus recovery will not work (A-004447). A different mechanism is needed which is documented in the P2040 Chip Errata Rev Q (latest available at the time of writing). Signed-off-by: Chris Packham Acked-by: Michael Ellerman Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin

MIPS: Fix kernel hang under FUNCTION_GRAPH_TRACER and PREEMPT_TRACER

2021-06-16T09:34:52+00:00

[ Upstream commit 78cf0eb926cb1abeff2106bae67752e032fe5f3e ] When update the latest mainline kernel with the following three configs, the kernel hangs during startup: (1) CONFIG_FUNCTION_GRAPH_TRACER=y (2) CONFIG_PREEMPT_TRACER=y (3) CONFIG_FTRACE_STARTUP_TEST=y When update the latest mainline kernel with the above two configs (1) and (2), the kernel starts normally, but it still hangs when execute the following command: echo "function_graph" > /sys/kernel/debug/tracing/current_tracer Without CONFIG_PREEMPT_TRACER=y, the above two kinds of kernel hangs disappeared, so it seems that CONFIG_PREEMPT_TRACER has some influences with function_graph tracer at the first glance. I use ejtag to find out the epc address is related with preempt_enable() in the file arch/mips/lib/mips-atomic.c, because function tracing can trace the preempt_{enable,disable} calls that are traced, replace them with preempt_{enable,disable}_notrace to prevent function tracing from going into an infinite loop, and then it can fix the kernel hang issue. By the way, it seems that this commit is a complement and improvement of commit f93a1a00f2bd ("MIPS: Fix crash that occurs when function tracing is enabled"). Signed-off-by: Tiezhu Yang Cc: Steven Rostedt Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin

arm64: Remove unimplemented syscall log message

2021-06-10T10:41:36+00:00

commit 1962682d2b2fbe6cfa995a85c53c069fadda473e upstream. Stop printing a (ratelimited) kernel message for each instance of an unimplemented syscall being called. Userland making an unimplemented syscall is not necessarily misbehaviour and to be expected with a current userland running on an older kernel. Also, the current message looks scary to users but does not actually indicate a real problem nor help them narrow down the cause. Just rely on sys_ni_syscall() to return -ENOSYS. Cc: Acked-by: Will Deacon Signed-off-by: Michael Weiser Signed-off-by: Will Deacon Signed-off-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman

KVM: SVM: Truncate GPR value for DR and CR accesses in !64-bit mode

2021-06-10T10:41:36+00:00

commit 0884335a2e653b8a045083aa1d57ce74269ac81d upstream. Drop bits 63:32 on loads/stores to/from DRs and CRs when the vCPU is not in 64-bit mode. The APM states bits 63:32 are dropped for both DRs and CRs: In 64-bit mode, the operand size is fixed at 64 bits without the need for a REX prefix. In non-64-bit mode, the operand size is fixed at 32 bits and the upper 32 bits of the destination are forced to 0. Fixes: 7ff76d58a9dc ("KVM: SVM: enhance MOV CR intercept handler") Fixes: cae3797a4639 ("KVM: SVM: enhance mov DR intercept handler") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson Message-Id: <20210422022128.3464144-4-seanjc@google.com> Signed-off-by: Paolo Bonzini [sudip: manual backport to old file] Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman

x86/entry/64: Add instruction suffix

2021-06-03T06:22:09+00:00

commit a368d7fd2a3c6babb852fe974018dd97916bcd3b upstream. Omitting suffixes from instructions in AT&T mode is bad practice when operand size cannot be determined by the assembler from register operands, and is likely going to be warned about by upstream gas in the future (mine does already). Add the single missing suffix here. Signed-off-by: Jan Beulich Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/5A93F96902000078001ABAC8@prv-mh.provo.novell.com Signed-off-by: Greg Kroah-Hartman