linux/arch/mips/kernel/entry.S, branch v4.9

MIPS: kernel: entry.S: Set correct ISA level for mips_ihb

2015-04-10T13:41:46Z

Commit 6ebb496ffc7e("MIPS: kernel: entry.S: Add MIPS R6 related definitions") added the MIPSR6 definition but it did not update the ISA level of the actual assembly code so a pre-MIPSR6 jr.hb instruction was generated instead. Fix this by using the MISP_ISA_LEVEL_RAW macro. Signed-off-by: Markos Chandras Fixes: 6ebb496ffc7e("MIPS: kernel: entry.S: Add MIPS R6 related definitions") Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9386/ Signed-off-by: Ralf Baechle

MIPS: Make use of the ERETNC instruction on MIPS R6

2015-02-17T15:37:37Z

The ERETNC instruction, introduced in MIPS R5, is similar to the ERET one, except it does not clear the LLB bit in the LLADDR register. This feature is necessary to safely emulate R2 LL/SC instructions. However, on context switches, we need to clear the LLAddr/LLB bit in order to make sure that an SC instruction from the new thread will never succeed if it happens to interrupt an LL operation on the same address from the previous thread. Signed-off-by: Markos Chandras

MIPS: kernel: entry.S: Add MIPS R6 related definitions

2015-02-17T15:37:26Z

The instruction hazard barrier in the form of: jr.hb ra nop is valid on MIPS R6 as well. Signed-off-by: Markos Chandras

MIPS: MT: Remove SMTC support

2014-05-23T22:07:01Z

Nobody is maintaining SMTC anymore and there also seems to be no userbase. Which is a pity - the SMTC technology primarily developed by Kevin D. Kissell is an ingenious demonstration for the MT ASE's power and elegance. Based on Markos Chandras patch https://patchwork.linux-mips.org/patch/6719/ which while very similar did no longer apply cleanly when I tried to merge it plus some additional post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to merge once upon a time. Signed-off-by: Ralf Baechle

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

2012-12-12T20:22:13Z

Pull big execve/kernel_thread/fork unification series from Al Viro: "All architectures are converted to new model. Quite a bit of that stuff is actually shared with architecture trees; in such cases it's literally shared branch pulled by both, not a cherry-pick. A lot of ugliness and black magic is gone (-3KLoC total in this one): - kernel_thread()/kernel_execve()/sys_execve() redesign. We don't do syscalls from kernel anymore for either kernel_thread() or kernel_execve(): kernel_thread() is essentially clone(2) with callback run before we return to userland, the callbacks either never return or do successful do_execve() before returning. kernel_execve() is a wrapper for do_execve() - it doesn't need to do transition to user mode anymore. As a result kernel_thread() and kernel_execve() are arch-independent now - they live in kernel/fork.c and fs/exec.c resp. sys_execve() is also in fs/exec.c and it's completely architecture-independent. - daemonize() is gone, along with its parts in fs/*.c - struct pt_regs * is no longer passed to do_fork/copy_process/ copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump. - sys_fork()/sys_vfork()/sys_clone() unified; some architectures still need wrappers (ones with callee-saved registers not saved in pt_regs on syscall entry), but the main part of those suckers is in kernel/fork.c now." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits) do_coredump(): get rid of pt_regs argument print_fatal_signal(): get rid of pt_regs argument ptrace_signal(): get rid of unused arguments get rid of ptrace_signal_deliver() arguments new helper: signal_pt_regs() unify default ptrace_signal_deliver flagday: kill pt_regs argument of do_fork() death to idle_regs() don't pass regs to copy_process() flagday: don't pass regs to copy_thread() bfin: switch to generic vfork, get rid of pointless wrappers xtensa: switch to generic clone() openrisc: switch to use of generic fork and clone unicore32: switch to generic clone(2) score: switch to generic fork/vfork/clone c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone() take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h mn10300: switch to generic fork/vfork/clone h8300: switch to generic fork/vfork/clone tile: switch to generic clone() ... Conflicts: arch/microblaze/include/asm/Kbuild

MIPS: Fix endless loop when processing signals for kernel tasks

2012-12-05T18:59:00Z

The problem occurs [1] when a kernel-mode task returns from a system call with a pending signal. A real-life scenario is a child of 'khelper' returning from a failed kernel_execve() in ____call_usermodehelper() [ kernel/kmod.c ]. kernel_execve() fails due to a pending SIGKILL, which is the result of "kill -9 -1" (at least, busybox's init does it upon reboot). The loop is as follows: * syscall_exit_work: - work_pending: // start_of_the_loop - work_notifysig: - do_notify_resume() - do_signal() - if (!user_mode(regs)) return; - resume_userspace // TIF_SIGPENDING is still set - work_pending // so we call work_pending => goto // start_of_the_loop More information can be found in another LKML thread: http://www.serverphorums.com/read.php?12,457826 [1] The problem was also reproduced on !CONFIG_VM86 x86, and the following fix was accepted. http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=29a2e2836ff9ea65a603c89df217f4198973a74f Signed-off-by: Dmitry Adamushko Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/3571/ Signed-off-by: Ralf Baechle

mips: switch to saner kernel_execve() semantics

2012-10-15T20:27:52Z

Acked-by: Ralf Baechle Signed-off-by: Al Viro

MIPS: Switch over to generic sys_execve and kernel_execve.

2012-10-14T23:31:30Z

This version contains a few updates by David Daney, in particular it's now using __builtin_frame_address() instead of asm() which depending on personal taste, is slightly more appealing. Signed-off-by: Ralf Baechle

mips: switch to generic kernel_thread()

2012-10-14T23:30:25Z

Signed-off-by: Al Viro

MIPS: Merge the identical "return from syscall" per-ABI code

2012-09-22T13:47:31Z

No need to keep 4 copies of that stuff; merged and taken to entry.S, unused public symbols there killed off. Signed-off-by: Al Viro Signed-off-by: Ralf Baechle