linux/arch/arc/include, branch v4.0

ARC: Fix thread_saved_pc()

2015-02-27T05:29:34Z

The old implementation assumed that SP at the time of __switch_to() is right above pt_regs which is almost certainly not the case as there will be some stack build up between entry into kernel and leading up to __switch_to Signed-off-by: Vineet Gupta

ARC: Fix KSTK_ESP()

2015-02-27T05:18:23Z

/proc//maps currently don't annotate stack vma with "[stack]" This is because KSTK_ESP ie expected to return usermode SP of tsk while currently it returns the kernel mode SP of a sleeping tsk. While the fix is trivial, we also need to adjust the ARC kernel stack unwinder to not use KSTK_SP and friends any more. Cc: Reported-and-suggested-by: Alexey Brodkin Signed-off-by: Vineet Gupta

ARC: Make arc_unwind_core accessible externally

2015-02-27T04:45:00Z

The arc unwinder can also be used for perf callchains. Signed-off-by: Mischa Jonker Signed-off-by: Vineet Gupta

Merge tag 'arc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

2015-02-16T22:56:52Z

Pull ARC updates from Vineet Gupta: "Some fixes, nothing too exciting this time as well..." * tag 'arc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: ARC: fix page address calculation if PAGE_OFFSET != LINUX_LINK_BASE ARC: Fix earlycon build breakage ARC: Dynamically determine BASE_BAUD from DeviceTree arc: Remove unused prepare_to_copy() ARC: use ACCESS_ONCE in cmpxchg loop ARC: add some more comments to ret_from_fork ARC: fix /proc/cpuinfo for offline cpus

ARC: fix page address calculation if PAGE_OFFSET != LINUX_LINK_BASE

2015-02-13T12:31:12Z

We used to calculate page address differently in 2 cases: 1. In virt_to_page(x) we do --->8--- mem_map + (x - CONFIG_LINUX_LINK_BASE) >> PAGE_SHIFT --->8--- 2. In in pte_page(x) we do --->8--- mem_map + (pte_val(x) - PAGE_OFFSET) >> PAGE_SHIFT --->8--- That leads to problems in case PAGE_OFFSET != CONFIG_LINUX_LINK_BASE - different pages will be selected depending on where and how we calculate page address. In particular in the STAR 9000853582 when gdb attempted to read memory of another process it got improper page in get_user_pages() because this is exactly one of the places where we search for a page by pte_page(). The fix is trivial - we need to calculate page address similarly in both cases. Cc: Signed-off-by: Alexey Brodkin Signed-off-by: Vineet Gupta

all arches, signal: move restart_block to struct task_struct

2015-02-13T02:54:12Z

If an attacker can cause a controlled kernel stack overflow, overwriting the restart block is a very juicy exploit target. This is because the restart_block is held in the same memory allocation as the kernel stack. Moving the restart block to struct task_struct prevents this exploit by making the restart_block harder to locate. Note that there are other fields in thread_info that are also easy targets, at least on some architectures. It's also a decent simplification, since the restart code is more or less identical on all architectures. [james.hogan@imgtec.com: metag: align thread_info::supervisor_stack] Signed-off-by: Andy Lutomirski Cc: Thomas Gleixner Cc: Al Viro Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Kees Cook Cc: David Miller Acked-by: Richard Weinberger Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Vineet Gupta Cc: Russell King Cc: Catalin Marinas Cc: Will Deacon Cc: Haavard Skinnemoen Cc: Hans-Christian Egtvedt Cc: Steven Miao Cc: Mark Salter Cc: Aurelien Jacquiot Cc: Mikael Starvik Cc: Jesper Nilsson Cc: David Howells Cc: Richard Kuo Cc: "Luck, Tony" Cc: Geert Uytterhoeven Cc: Michal Simek Cc: Ralf Baechle Cc: Jonas Bonn Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Acked-by: Michael Ellerman (powerpc) Tested-by: Michael Ellerman (powerpc) Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Chen Liqin Cc: Lennox Wu Cc: Chris Metcalf Cc: Guan Xuetao Cc: Chris Zankel Cc: Max Filippov Cc: Oleg Nesterov Cc: Guenter Roeck Signed-off-by: James Hogan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: make FIRST_USER_ADDRESS unsigned long on all archs

2015-02-12T01:06:03Z

LKP has triggered a compiler warning after my recent patch "mm: account pmd page tables to the process": mm/mmap.c: In function 'exit_mmap': >> mm/mmap.c:2857:2: warning: right shift count >= width of type [enabled by default] The code: > 2857 WARN_ON(mm_nr_pmds(mm) > 2858 round_up(FIRST_USER_ADDRESS, PUD_SIZE) >> PUD_SHIFT); In this, on tile, we have FIRST_USER_ADDRESS defined as 0. round_up() has the same type -- int. PUD_SHIFT. I think the best way to fix it is to define FIRST_USER_ADDRESS as unsigned long. On every arch for consistency. Signed-off-by: Kirill A. Shutemov Reported-by: Wu Fengguang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arc: drop _PAGE_FILE and pte_file()-related helpers

2015-02-10T22:30:31Z

We've replaced remap_file_pages(2) implementation with emulation. Nobody creates non-linear mapping anymore. Signed-off-by: Kirill A. Shutemov Acked-by: Vineet Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ARC: Dynamically determine BASE_BAUD from DeviceTree

2015-02-02T11:38:37Z

8250 earlycon is broken on multi-platform ARC because the UART clk value (BASE_BAUD) is fixed at build time. Instead, determine the appropriate UART clk at runtime; parse the devicetree early for platforms requiring alternate UART clk values (currently only the TB10X platform). Cc: Jiri Slaby Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Rob Herring Cc: Arnd Bergmann Reviewed-by: Peter Hurley Acked-by: Greg Kroah-Hartman Signed-off-by: Vineet Gupta

arc: Remove unused prepare_to_copy()

2015-02-02T11:38:37Z

prepare_to_copy() was removed from all architectures supported at that time in commit 55ccf3fe3f9a ("fork: move the real prepare_to_copy() users to arch_dup_task_struct()"). Remove it from arc as well. Signed-off-by: Tobias Klauser Signed-off-by: Vineet Gupta