kernel.git/arch/arm64, branch linux-3.17.y

arm64: Add COMPAT_HWCAP_LPAE

2015-01-08T18:27:46Z

commit 7d57511d2dba03a8046c8b428dd9192a4bfc1e73 upstream. Commit a469abd0f868 (ARM: elf: add new hwcap for identifying atomic ldrd/strd instructions) introduces HWCAP_ELF for 32-bit ARM applications. As LPAE is always present on arm64, report the corresponding compat HWCAP to user space. Signed-off-by: Catalin Marinas Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

Correct the race condition in aarch64_insn_patch_text_sync()

2014-11-21T17:23:12Z

commit 899d5933b2dd2720f2b20b01eaa07871aa6ad096 upstream. When experimenting with patches to provide kprobes support for aarch64 smp machines would hang when inserting breakpoints into kernel code. The hangs were caused by a race condition in the code called by aarch64_insn_patch_text_sync(). The first processor in the aarch64_insn_patch_text_cb() function would patch the code while other processors were still entering the function and incrementing the cpu_count field. This resulted in some processors never observing the exit condition and exiting the function. Thus, processors in the system hung. The first processor to enter the patching function performs the patching and signals that the patching is complete with an increment of the cpu_count field. When all the processors have incremented the cpu_count field the cpu_count will be num_cpus_online()+1 and they will return to normal execution. Fixes: ae16480785de arm64: introduce interfaces to hotpatch kernel and module code Signed-off-by: William Cohen Acked-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

arm64: efi: Fix stub cache maintenance

2014-11-21T17:23:12Z

commit 9b0b26580a753d4d6bdd2b8b4ca9a8f3f2d39065 upstream. While efi-entry.S mentions that efi_entry() will have relocated the kernel image, it actually means that efi_entry will have placed a copy of the kernel in the appropriate location, and until this is branched to at the end of efi_entry.S, all instructions are executed from the original image. Thus while the flush in efi_entry.S does ensure that the copy is visible to noncacheable accesses, it does not guarantee that this is true for the image instructions are being executed from. This could have disasterous effects when the MMU and caches are disabled if the image has not been naturally evicted to the PoC. Additionally, due to a missing dsb following the ic ialluis, the new kernel image is not necessarily clean in the I-cache when it is branched to, with similar potentially disasterous effects. This patch adds additional flushing to ensure that the currently executing stub text is flushed to the PoC and is thus visible to noncacheable accesses. As it is placed after the instructions cache maintenance for the new image and __flush_dcache_area already contains a dsb, we do not need to add a separate barrier to ensure completion of the icache maintenance. Comments are updated to clarify the situation with regard to the two images and the maintenance required for both. Fixes: 3c7f255039a2ad6ee1e3890505caf0d029b22e29 Signed-off-by: Mark Rutland Acked-by: Joel Schopp Reviewed-by: Roy Franz Tested-by: Tom Lendacky Cc: Ard Biesheuvel Cc: Ian Campbell Cc: Leif Lindholm Cc: Mark Salter Cc: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

arm64: __clear_user: handle exceptions on strb

2014-11-21T17:23:12Z

commit 97fc15436b36ee3956efad83e22a557991f7d19d upstream. ARM64 currently doesn't fix up faults on the single-byte (strb) case of __clear_user... which means that we can cause a nasty kernel panic as an ordinary user with any multiple PAGE_SIZE+1 read from /dev/zero. i.e.: dd if=/dev/zero of=foo ibs=1 count=1 (or ibs=65537, etc.) This is a pretty obscure bug in the general case since we'll only __do_kernel_fault (since there's no extable entry for pc) if the mmap_sem is contended. However, with CONFIG_DEBUG_VM enabled, we'll always fault. if (!down_read_trylock(&mm->mmap_sem)) { if (!user_mode(regs) && !search_exception_tables(regs->pc)) goto no_context; retry: down_read(&mm->mmap_sem); } else { /* * The above down_read_trylock() might have succeeded in * which * case, we'll have missed the might_sleep() from * down_read(). */ might_sleep(); if (!user_mode(regs) && !search_exception_tables(regs->pc)) goto no_context; } Fix that by adding an extable entry for the strb instruction, since it touches user memory, similar to the other stores in __clear_user. Signed-off-by: Kyle McMartin Reported-by: Miloš Prchlík Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

arm64: compat: fix compat types affecting struct compat_elf_prpsinfo

2014-10-30T16:43:11Z

commit 971a5b6fe634bb7b617d8c5f25b6a3ddbc600194 upstream. The compat_elf_prpsinfo structure does not match the arch/arm struct elf_pspsinfo definition. As result NT_PRPSINFO note in core file created by arm64 kernel for aarch32 (compat) process has wrong size. So gdb cannot display command that caused process crash. Fix is to change size of __compat_uid_t, __compat_gid_t so it would match size of similar fields in arch/arm case. Signed-off-by: Victor Kamensky Acked-by: Arnd Bergmann Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

arm64: Fix compilation error on UP builds

2014-10-30T16:43:11Z

commit ceab3fe69408cb98f437dad3b4b4bb79434370ef upstream. In file included from ./arch/arm64/include/asm/irq_work.h:4:0, from include/linux/irq_work.h:46, from include/linux/perf_event.h:49, from include/linux/ftrace_event.h:9, from include/trace/syscall.h:6, from include/linux/syscalls.h:81, from init/main.c:18: ./arch/arm64/include/asm/smp.h:24:3: error: #error " included in non-SMP build" # error " included in non-SMP build" Signed-off-by: Catalin Marinas Fixes: 3631073659d0 ("arm64: Tell irq work about self IPI support") Reported-by: Guenter Roeck Tested-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

arm64: debug: don't re-enable debug exceptions on return from el1_dbg

2014-10-30T16:43:08Z

commit 1059c6bf8534acda249e7e65c81e7696fb074dc1 upstream. When returning from a debug exception taken from EL1, we unmask debug exceptions after handling the exception. This is crucial for debug exceptions taken from EL0, so that any kernel work on the ret_to_user path can be debugged by kgdb. However, when returning back to EL1 the only thing left to do is to restore the original register state before the exception return. If single-step has been enabled by the debug exception handler, we will get stuck in an infinite debug exception loop, since we will take the step exception as soon as we unmask debug exceptions. This patch avoids unmasking debug exceptions on the debug exception return path when the exception was taken from EL1. Fixes: 2a2830703a23 (arm64: debug: avoid accessing mdscr_el1 on fault paths where possible) Reported-by: David Long Reported-by: AKASHI Takahiro Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

arm64: Tell irq work about self IPI support

2014-10-15T10:29:25Z

commit 3631073659d0aafeaa52227bb61a100efaf901dc upstream. ARM64 irq work self-IPI support depends on __smp_cross_call to point to some relevant IRQ controller operations. This information should be available after the call to init_IRQ(). Lets implement arch_irq_work_has_interrupt() accordingly. Acked-by: Peter Zijlstra (Intel) Acked-by: Catalin Marinas Cc: Ingo Molnar Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Frederic Weisbecker Signed-off-by: Greg Kroah-Hartman

irq_work: Introduce arch_irq_work_has_interrupt()

2014-10-15T10:29:23Z

commit c5c38ef3d70377dc504a6a3f611a3ec814bc757b upstream. The nohz full code needs irq work to trigger its own interrupt so that the subsystem can work even when the tick is stopped. Lets introduce arch_irq_work_has_interrupt() that archs can override to tell about their support for this ability. Signed-off-by: Peter Zijlstra Cc: Ingo Molnar Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Frederic Weisbecker Signed-off-by: Greg Kroah-Hartman

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-09-19T16:07:47Z

Pull x86 fixes from Ingo Molnar: "Misc fixes: EFI fixes, a build fix, a page table dumping (debug) fix and a clang build fix" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi/arm64: Fix fdt-related memory reservation x86/mm: Apply the section attribute to the variable, not its type x86/efi: Fixup GOT in all boot code paths x86/efi: Only load initrd above 4g on second try x86-64, ptdump: Mark espfix area only if existent x86, irq: Fix build error caused by 9eabc99a635a77cbf09