commit 8536a5ef886005bc443c2da9b842d69fd3d7647f upstream.
The Thumb2 version of the FP exception handling entry code treats the
register holding the CP number (R8) differently, resulting in the iWMMXT
CP number check to be incorrect.
Fix this by unifying the ARM and Thumb2 code paths, and switch the
order of the additions of the TI_USED_CP offset and the shifted CP
index.
Cc: <stable@vger.kernel.org>
Fixes: b86040a59feb ("Thumb-2: Implementation of the unified start-up and exceptions code")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mark Brand reports that a NEEDS_SYSCALL_FOR_CMPXCHG enabled kernel would open a security hole in the ghost syscall used to implement cmpxchg, as it fails to validate the user pointer. However, in order for this option to be enabled, you'd need to be building a pre-ARMv6 kernel with SMP support. There is only one system known which fits that, which is an early ARM SMP FPGA implementation based on the ARM926T. In any case, the Kconfig does not allow SMP to be enabled for pre-ARMv6 systems. Moreover, even if NEEDS_SYSCALL_FOR_CMPXCHG were to be enabled, the kernel would not build as __ARM_NR_cmpxchg64 is not defined. The simple answer is to remove the buggy code. Reported-by: Mark Brand <markbrand@google.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Provide hooks into the kernel entry and exit paths to permit control of userspace visibility to the kernel. The intended use is: - on entry to kernel from user, uaccess_disable will be called to disable userspace visibility - on exit from kernel to user, uaccess_enable will be called to enable userspace visibility - on entry from a kernel exception, uaccess_save_and_disable will be called to save the current userspace visibility setting, and disable access - on exit from a kernel exception, uaccess_restore will be called to restore the userspace visibility as it was before the exception occurred. These hooks allows us to keep userspace visibility disabled for the vast majority of the kernel, except for localised regions where we want to explicitly access userspace. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rather than modifying both the domain access control register and our per-thread copy, modify only the domain access control register, and use the per-thread copy to save and restore the register over context switches. We can also avoid the explicit initialisation of the init thread_info structure. This allows us to avoid needing to gain access to the thread information at the uaccess control sites. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pull ARM updates from Russell King: "These are late by a week; they should have been merged during the merge window, but unfortunately, the ARM kernel build/boot farms were indicating random failures, and it wasn't clear whether the cause was something in these changes or something during the merge window. This is a set of merge window fixes with some documentation additions" * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: ARM: avoid unwanted GCC memset()/memcpy() optimisations for IO variants ARM: pgtable: document mapping types ARM: io: convert ioremap*() to functions ARM: io: fix ioremap_wt() implementation ARM: io: document ARM specific behaviour of ioremap*() implementations ARM: fix lockdep unannotated irqs-off warning ARM: 8397/1: fix vdsomunge not to depend on glibc specific error.h ARM: add helpful message when truncating physical memory ARM: add help text for HIGHPTE configuration entry ARM: fix DEBUG_SET_MODULE_RONX build dependencies ARM: 8396/1: use phys_addr_t in pfn_to_kaddr() ARM: 8394/1: update memblock limit after mapping lowmem ARM: 8393/1: smp: Fix suspicious RCU usage with ipi tracepoints
Wolfram Sang reported an unannotated irqs-off warning from lockdep: WARNING: CPU: 0 PID: 282 at kernel/locking/lockdep.c:3557 check_flags+0x84/0x1f4() DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled) CPU: 0 PID: 282 Comm: rcS Tainted: G W 4.1.0-00002-g5b076054611833 #179 Hardware name: Generic Emma Mobile EV2 (Flattened Device Tree) Backtrace: [<c0012c94>] (dump_backtrace) from [<c0012e3c>] (show_stack+0x18/0x1c) r6:c02dcc67 r5:00000009 r4:00000000 r3:00400000 [<c0012e24>] (show_stack) from [<c02510c8>] (dump_stack+0x20/0x28) [<c02510a8>] (dump_stack) from [<c0022c44>] (warn_slowpath_common+0x8c/0xb4) [<c0022bb8>] (warn_slowpath_common) from [<c0022cd8>] (warn_slowpath_fmt+0x38/0x40) r8:c780f470 r7:00000000 r6:00000000 r5:c03b0570 r4:c0b7ec04 [<c0022ca4>] (warn_slowpath_fmt) from [<c004cd38>] (check_flags+0x84/0x1f4) r3:c02e13d8 r2:c02dceaa [<c004ccb4>] (check_flags) from [<c0050e50>] (lock_acquire+0x4c/0xbc) r5:00000000 r4:60000193 [<c0050e04>] (lock_acquire) from [<c0256000>] (_raw_spin_lock+0x34/0x44) r9:000a8d5c r8:00000001 r7:c7806000 r6:c780f460 r5:c03b06a0 r4:c780f460 [<c0255fcc>] (_raw_spin_lock) from [<c005a8cc>] (handle_fasteoi_irq+0x20/0x11c) r4:c780f400 [<c005a8ac>] (handle_fasteoi_irq) from [<c0057a4c>] (generic_handle_irq+0x28/0x38) r6:00000000 r5:c03b038c r4:00000012 r3:c005a8ac [<c0057a24>] (generic_handle_irq) from [<c0057ae4>] (__handle_domain_irq+0x88/0xa8) r4:00000000 r3:00000026 [<c0057a5c>] (__handle_domain_irq) from [<c000a3cc>] (gic_handle_irq+0x40/0x58) r8:10c5347d r7:10c5347d r6:c35b1fb0 r5:c03a6304 r4:c8802000 r3:c35b1fb0 [<c000a38c>] (gic_handle_irq) from [<c0013bc8>] (__irq_usr+0x48/0x60) Exception stack(0xc35b1fb0 to 0xc35b1ff8) 1fa0: 00000061 00000000 000ab736 00000066 1fc0: 00000061 000aa1f0 000a8d54 000a8d54 000a8d88 000a8d5c 000a8cc8 000a8d68 1fe0: 72727272 bef8a528 000398c0 00031334 20000010 ffffffff r6:ffffffff r5:20000010 r4:00031334 r3:00000061 ---[ end trace cb88537fdc8fa202 ]--- possible reason: unannotated irqs-off. irq event stamp: 769 hardirqs last enabled at (769): [<c000f82c>] ret_fast_syscall+0x2c/0x54 hardirqs last disabled at (768): [<c000f80c>] ret_fast_syscall+0xc/0x54 softirqs last enabled at (0): [<c0020ec4>] copy_process.part.65+0x2e8/0x11dc softirqs last disabled at (0): [< (null)>] (null) His kernel configuration had: CONFIG_PROVE_LOCKING=y CONFIG_TRACE_IRQFLAGS=y but no IRQSOFF_TRACER, which means entry from userspace can result in the kernel seeing IRQs off without being notified of that change of state. Change the IRQSOFF ifdef in the usr_entry macro to TRACE_IRQFLAGS instead. Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pull init.h/module.h fragility fixes from Paul Gortmaker: "Fixup various init.h misuses that are fragile wrt code moving to module.h What started as a removal of no longer required include <linux/init.h> due to the earlier __cpuinit and __devinit removal led to the observation that some module specfic support was living in init.h itself, thus preventing the full removal from introducing compile regressions. This series includes a few final fixups needed prior to the relocation of the modular init code from <init.h> to <module.h>. These are things that weren't easily categorized into any of the other previous series categories already requested for pull. That said, each fixup branch (including this one) is independent and there are no ordering constraints. Only the final code relocation (which is NOT in this pull) requires that all my cleanup branches be merged first" * tag 'module-misc-v4.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: tile: add init.h to usb.c to avoid compile failure arm: fix implicit #include <linux/init.h> in entry asm. x86: replace __init_or_module with __init in non-modular vsmp_64.c
They use the "_INIT" macro and friends, and hence need to source this header file, vs. relying on getting it implicitly. Cc: Russell King <linux@arm.linux.org.uk> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>