commit 2b2040af0b64cd93e5d4df2494c4486cf604090d upstream. get_user may fail to load from the provided __user address due to an unhandled fault generated by the access. In the case of the undefined instruction trap, this results in failure to load the faulting instruction, in which case we should send SIGILL to the task rather than continue with potentially uninitialised data. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 15ac49b65024f55c4371a53214879a9c77c4fbf9 upstream. While trying to get a v3.5 kernel booted on the cubox, I noticed that VFP does not work correctly with VFP bounce handling. This is because of the confusion over 16-bit vs 32-bit instructions, and where PC is supposed to point to. The rule is that FP handlers are entered with regs->ARM_pc pointing at the _next_ instruction to be executed. However, if the exception is not handled, regs->ARM_pc points at the faulting instruction. This is easy for ARM mode, because we know that the next instruction and previous instructions are separated by four bytes. This is not true of Thumb2 though. Since all FP instructions are 32-bit in Thumb2, it makes things easy. We just need to select the appropriate adjustment. Do this by moving the adjustment out of do_undefinstr() into the assembly code, as only the assembly code knows whether it's dealing with a 32-bit or 16-bit instruction. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit fa18484d0947b976a769d15c83c50617493c81c1.
We need the restart trampoline back so that we can revert a related
problematic patch 6b5c8045ecc7e726cdaa2a9d9c8e5008050e1252 ("arm: new
way of handling ERESTART_RESTARTBLOCK").
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Conflicts: arch/arm/kernel/ptrace.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The cacheflush syscall can fail for two reasons: (1) The arguments are invalid (nonsensical address range or no VMA) (2) The region generates a translation fault on a VIPT or PIPT cache This patch allows do_cache_op to return an error code to userspace in the case of the above. The various coherent_user_range implementations are modified to return 0 in the case of VIVT caches or -EFAULT in the case of an abort on v6/v7 cores. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We can't be holding the mmap_sem while calling flush_cache_user_range because the flush can fault. If we fault on a user address, the page fault handler will try to take mmap_sem again. Since both places acquire the read lock, most of the time it succeeds. However, if another thread tries to acquire the write lock on the mmap_sem (e.g. mmap) in between the call to flush_cache_user_range and the fault, the down_read in do_page_fault will deadlock. [will: removed drop of vma parameter as already queued by rmk (7365/1)] Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Dima Zavin <dima@android.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
vma isn't used and flush_cache_user_range isn't a standard macro that is used on several archs with the same prototype. In fact only unicore32 has a macro with the same name (with an identical implementation and no in-tree users). This is a part of a patch proposed by Dima Zavin (with Message-id: 1272439931-12795-1-git-send-email-dima@android.com) that didn't get accepted. Cc: Dima Zavin <dima@android.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pull more ARM updates from Russell King. This got a fair number of conflicts with the <asm/system.h> split, but also with some other sparse-irq and header file include cleanups. They all looked pretty trivial, though. * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (59 commits) ARM: fix Kconfig warning for HAVE_BPF_JIT ARM: 7361/1: provide XIP_VIRT_ADDR for no-MMU builds ARM: 7349/1: integrator: convert to sparse irqs ARM: 7259/3: net: JIT compiler for packet filters ARM: 7334/1: add jump label support ARM: 7333/2: jump label: detect %c support for ARM ARM: 7338/1: add support for early console output via semihosting ARM: use set_current_blocked() and block_sigmask() ARM: exec: remove redundant set_fs(USER_DS) ARM: 7332/1: extract out code patch function from kprobes ARM: 7331/1: extract out insn generation code from ftrace ARM: 7330/1: ftrace: use canonical Thumb-2 wide instruction format ARM: 7351/1: ftrace: remove useless memory checks ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path ARM: Versatile Express: add NO_IOPORT ARM: get rid of asm/irq.h in asm/prom.h ARM: 7319/1: Print debug info for SIGBUS in user faults ARM: 7318/1: gic: refactor irq_start assignment ARM: 7317/1: irq: avoid NULL check in for_each_irq_desc loop ARM: 7315/1: perf: add support for the Cortex-A7 PMU ...
Disintegrate asm/system.h for ARM. Signed-off-by: David Howells <dhowells@redhat.com> cc: Russell King <linux@arm.linux.org.uk> cc: linux-arm-kernel@lists.infradead.org