| Message ID | 20210525183302.56293-1-mark.rutland@arm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | arm64: entry: migrate more code to C | expand |
On Tue, May 25, 2021 at 07:32:42PM +0100, Mark Rutland wrote: > Mark Rutland (20): > arm64: remove redundant local_daif_mask() in bad_mode() > arm64: entry: unmask IRQ+FIQ after EL0 handling > arm64: entry: convert SError handlers to C > arm64: entry: move arm64_preempt_schedule_irq to entry-common.c > arm64: entry: move preempt logic to C > arm64: entry: add a call_on_irq_stack helper > arm64: entry: convert IRQ+FIQ handlers to C > arm64: entry: organise entry handlers consistently > arm64: entry: organise entry vectors consistently > arm64: entry: consolidate EL1 exception returns > arm64: entry: move bad_mode() to entry-common.c > arm64: entry: improve bad_mode() > arm64: entry: template the entry asm functions > arm64: entry: handle all vectors with C > arm64: entry: fold el1_inv() into el1h_64_sync_handler() > arm64: entry: split bad stack entry > arm64: entry: split SDEI entry > arm64: entry: make NMI entry/exit functions static > arm64: entry: don't instrument entry code with KCOV > arm64: idle: don't instrument idle code with KCOV I can't claim I did an in-depth review (I may if they don't land in for-next/core by next week) but overall the series looks good to me: Acked-by: Catalin Marinas <catalin.marinas@arm.com>
On Tue, 25 May 2021 19:32:42 +0100, Mark Rutland <mark.rutland@arm.com> wrote: > > This series (based on v5.13-rc2) migrates most of the remaining > exception triage assembly to C. All the exception vectors are given C > handlers, so that we can defer all decision making to C code, and the > assembly code can be made simpler and more uniform. At the same time, > I've tried to consolidate all the entry sequencing (e.g. reading > exception registers and calling accounting code) in entry-common.c so > that this is easier to maintain. > > I was recently informed that `noinstr` wasn't protecting entry sequences > from KCOV instrumentation, so I've refactored things so that we can > avoid this by preventing KCOV instrumentation for the entirety of > entry-common.c. I've done likewise for the low-level idle sequences > which have the same problems with instrumentation when RCU isn't > watching, etc. > > I've stopped short of converting the ret_to_user / work_pending loop. > Converting this cleanly will probably need something like the wrappers > generated by SYSCALL_DEFINE() to handle the common entry/exit logic, and > this is easier to build once all the handlers have been converted to C. > Similar is true for portions of kernel_entry and kernel_exit that could > be converted to C. > > It should also be possible to generate the vectors and their associated > assembly handlers in one go by placing these in separate sections and > using .pushsection and .popsection. I've held off doing this for now as > this probably requires some changes to the linker script, and regardless > it should be easier to make that change atop this series. > > So far this has seen some light boot testing, and a day's worth of fuzzing > under Syzkaller, which I intend to leave to soak for a while. > > I've pushed the series to my arm64/entry/rework branch on kernel.org: > > https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git/log/?h=arm64/entry/rework > git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git arm64/entry/rework > > I've tagged this version as arm64-entry-rework-20210525. > > Since v1 [1] > * Rebase to v5.13-rc2 > * Fold NMI entry/exit sequencing into entry-common.c > * Make NMI entry/exit helpers private to entry-comomn.c > * Prevent KCOV instrumentation of entry-common.c > * Prevent KCOV instrumentation of idle code > > Since v2 [2]: > * Correct commit message description in patch 2 > * Use `el0t` prefix for EL0 handlers for consistency with `el1h` and `el1t` > * Remove `user_exit_irqoff` macro > * Remove leftover bad_mode() prototype > * Add patch to replace el1_inv() with a direct call to __panic_unhandled() > * Accumulate Reviewed-by tags > * Typo fixes > > [1] https://lore.kernel.org/r/20210510155621.52811-1-mark.rutland@arm.com > [2] https://lore.kernel.org/r/20210519123902.2452-1-mark.rutland@arm.com I've been through the patches and couldn't spot anything wrong, although I had to apply the patches and look at the final result. I also tested it lightly on a few odd machines, and nothing caught fire. So FWIW: Acked-by: Marc Zyngier <maz@kernel.org> M.