Addition of vDSO support for parisc in kernel v5.18 suddenly broke glibc
signal testcases on a 32-bit kernel.
The trampoline code (sigtramp.S) which is mapped into userspace includes
an offset to the context data on the stack, which is used by gdb and
glibc to get access to registers.
In a 32-bit kernel we used by mistake the offset into the compat context
(which is valid on a 64-bit kernel only) instead of the offset into the
"native" 32-bit context.
Reported-by: John David Anglin <dave.anglin@bell.net>
Tested-by: John David Anglin <dave.anglin@bell.net>
Fixes: df24e1783e ("parisc: Add vDSO support")
CC: stable@vger.kernel.org # 5.18
Signed-off-by: Helge Deller <deller@gmx.de>
The commit e8aa7b17fe broke the 32-bit load-word unalignment exception
handler because it calculated the wrong amount of bits by which the value
should be shifted. This patch fixes it.
Signed-off-by: Helge Deller <deller@gmx.de>
Fixes: e8aa7b17fe ("parisc/unaligned: Rewrite inline assembly of emulate_ldw()")
Cc: stable@vger.kernel.org # v5.18
Anonymous pages are allocated with the shared mappings colouring,
SHM_COLOUR. Since the alias boundary on machines with PA8800 and
PA8900 processors is unknown, flush_user_cache_page() might not
flush all mappings of a shared anonymous page. Flushing the whole
data cache flushes all mappings.
This won't fix all coherency issues with shared mappings but it
seems to work well in practice. I haven't seen any random memory
faults in almost a month on a rp3440 running as a debian buildd
machine.
There is a small preformance hit.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.18+
Pull more parisc architecture updates from Helge Deller:
"A fix to prevent crash at bootup if CONFIG_SCHED_MC is enabled, and
add auto-detection of primary graphics card for framebuffer driver"
* tag 'for-5.19/parisc-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc/stifb: Keep track of hardware path of graphics card
parisc/stifb: Implement fb_is_primary_device()
parisc: fix a crash with multicore scheduler
Pull kthread updates from Eric Biederman:
"This updates init and user mode helper tasks to be ordinary user mode
tasks.
Commit 40966e316f ("kthread: Ensure struct kthread is present for
all kthreads") caused init and the user mode helper threads that call
kernel_execve to have struct kthread allocated for them. This struct
kthread going away during execve in turned made a use after free of
struct kthread possible.
Here, commit 343f4c49f2 ("kthread: Don't allocate kthread_struct for
init and umh") is enough to fix the use after free and is simple
enough to be backportable.
The rest of the changes pass struct kernel_clone_args to clean things
up and cause the code to make sense.
In making init and the user mode helpers tasks purely user mode tasks
I ran into two complications. The function task_tick_numa was
detecting tasks without an mm by testing for the presence of
PF_KTHREAD. The initramfs code in populate_initrd_image was using
flush_delayed_fput to ensuere the closing of all it's file descriptors
was complete, and flush_delayed_fput does not work in a userspace
thread.
I have looked and looked and more complications and in my code review
I have not found any, and neither has anyone else with the code
sitting in linux-next"
* tag 'kthread-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
sched: Update task_tick_numa to ignore tasks without an mm
fork: Stop allowing kthreads to call execve
fork: Explicitly set PF_KTHREAD
init: Deal with the init process being a user mode process
fork: Generalize PF_IO_WORKER handling
fork: Explicity test for idle tasks in copy_thread
fork: Pass struct kernel_clone_args into copy_thread
kthread: Don't allocate kthread_struct for init and umh
With the kernel 5.18, the system will hang on boot if it is compiled with
CONFIG_SCHED_MC. The last printed message is "Brought up 1 node, 1 CPU".
The crash happens in sd_init
tl->mask (which is cpu_coregroup_mask) returns an empty mask. This happens
because cpu_topology[0].core_sibling is empty.
Consequently, sd_span is set to an empty mask
sd_id = cpumask_first(sd_span) sets sd_id == NR_CPUS (because the mask is
empty)
sd->shared = *per_cpu_ptr(sdd->sds, sd_id); sets sd->shared to NULL
because sd_id is out of range
atomic_inc(&sd->shared->ref); crashes without printing anything
We can fix it by calling reset_cpu_topology() from init_cpu_topology() -
this will initialize the sibling masks on CPUs, so that they're not empty.
This patch also removes the variable "dualcores_found", it is useless,
because during boot, init_cpu_topology is called before
store_cpu_topology. Thus, set_sched_topology(parisc_mc_topology) is never
called. We don't need to call it at all because default_topology in
kernel/sched/topology.c contains the same items as parisc_mc_topology.
Note that we should not call store_cpu_topology() from init_per_cpu()
because it is called too early in the kernel initialization process and it
results in the message "Failure to register CPU0 device". Before this
patch, store_cpu_topology() would exit immediatelly because
cpuid_topo->core id was uninitialized and it was 0.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org # v5.18
Signed-off-by: Helge Deller <deller@gmx.de>
Pull parisc architecture updates from Helge Deller:
"Minor cleanups and code optimizations, e.g.:
- improvements in assembly statements in the tmpalias code path
- added some additionals compile time checks
- drop some unneccesary assembler DMA syncs"
* tag 'for-5.19/parisc-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Drop __ARCH_WANT_OLD_READDIR and __ARCH_WANT_SYS_OLDUMOUNT
parisc: Optimize tmpalias function calls
parisc: Add dep_safe() macro to deposit a register in 32- and 64-kernels
parisc: Fix wrong comment for shr macro
parisc: Prevent ldil() to sign-extend into upper 32 bits
parisc: Don't hardcode assembler bit definitions in tmpalias code
parisc: Don't enforce DMA completion order in cache flushes
parisc: video: fbdev: stifb: Add sti_dump_font() to dump STI font
Instead of converting the physical address of the tmpalias mapping to
the tlb insert format inside all the various tmpalias functions, move
this conversion over to the DTLB miss handler. The physical address is
already in %r26 (or will be calculated into %r23), so there are no
additional steps needed in the functions themselves.
Additionally use the dep_safe() and depi_safe() macros to avoid
differentiating between 32- and 64-bit builds and as such make the code
much more readable.
The check if "ldil L%(TMPALIAS_MAP_START)" will sign extend into the
upper 32 bits can be dropped, because we added a compile time check in
an earlier patch.
Signed-off-by: Helge Deller <deller@gmx.de>
Remove the hardcoded bit definitions in the tmpalias assembly code.
This makes it easy to change the size of the tmpalias region.
The alignment of the tmpalias region is reduced from 16 MB to 8 MB.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
The only place we need to ensure all outstanding cache coherence
operations are complete is in invalidate_kernel_vmap_range. All
parisc drivers synchronize DMA operations internally and do not
call invalidate_kernel_vmap_range. We only need this for non-coherent
I/O operations.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Kernel now supports chained power-off handlers. Use do_kernel_power_off()
that invokes chained power-off handlers. It also invokes legacy
pm_power_off() for now, which will be removed once all drivers will
be converted to the new sys-off API.
Acked-by: Helge Deller <deller@gmx.de> # parisc
Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This change fixes the following:
1) The flags variable is not initialized. Always use raw_spin_lock_irqsave
and raw_spin_unlock_irqrestore to serialize patching.
2) flush_kernel_vmap_range is primarily intended for DMA flushes.
The whole cache flush in flush_kernel_vmap_range is only possible
when interrupts are enabled on SMP machines. Since __patch_text_multiple
calls flush_kernel_vmap_range with interrupts disabled, it is better
to directly call flush_kernel_dcache_range_asm and
flush_kernel_icache_range_asm.
3) The final call to flush_icache_range is unnecessary.
Tested with `[PATCH, V3] parisc: Rewrite cache flush code for
PA8800/PA8900' change on rp3440, c8000 and c3750 (32 and 64-bit).
Note by Helge:
This patch had been temporarily reverted shortly before v5.18-rc6 in order
to fix boot issues. Now it can be re-applied.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Originally, I was convinced that we needed to use tmpalias flushes
everwhere, for both user and kernel flushes. However, when I modified
flush_kernel_dcache_page_addr, to use a tmpalias flush, my c8000
would crash quite early when booting.
The PDC returns alias values of 0 for the icache and dcache. This
indicates that either the alias boundary is greater than 16MB or
equivalent aliasing doesn't work. I modified the tmpalias code to
make it easy to try alternate boundaries. I tried boundaries up to
128MB but still kernel tmpalias flushes didn't work on c8000.
This led me to conclude that tmpalias flushes don't work on PA8800
and PA8900 machines, and that we needed to flush directly using the
virtual address of user and kernel pages. This is likely the major
cause of instability on the c8000 and rp34xx machines.
Flushing user pages requires doing a temporary context switch as we
have to flush pages that don't belong to the current context. Further,
we have to deal with pages that aren't present. If a page isn't
present, the flush instructions fault on every line.
Other code has been rearranged and simplified based on testing. For
example, I introduced a flush_cache_dup_mm routine. flush_cache_mm
and flush_cache_dup_mm differ in that flush_cache_mm calls
purge_cache_pages and flush_cache_dup_mm calls flush_cache_pages.
In some implementations, pdc is more efficient than fdc. Based on
my testing, I don't believe there's any performance benefit on the
c8000.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
The cr16 interval timers are not synchronized across CPUs, even with just
one dual-core CPU. This becomes visible if the machines have a longer
uptime.
Signed-off-by: Helge Deller <deller@gmx.de>
Various spelling mistakes in comments.
Detected with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Helge Deller <deller@gmx.de>
The Linux tool "lscpu" shows the double amount of CPUs if we have
"model" and "model name" in two different lines in /proc/cpuinfo.
This change combines the model and the model name into one line.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
The inventory knows which CPUs are in the system, so this bitmask should
be in cpu_possible_mask instead of the bitmask based on CONFIG_NR_CPUS.
Reset the cpu_possible_mask before scanning the system for CPUs, and
mark each existing CPU as possible during initialization of that CPU.
This avoids those warnings later on too:
register_cpu_capacity_sysctl: too early to get CPU4 device!
Signed-off-by: Helge Deller <deller@gmx.de>
Noticed-by: John David Anglin <dave.anglin@bell.net>
Add fn and fn_arg members into struct kernel_clone_args and test for
them in copy_thread (instead of testing for PF_KTHREAD | PF_IO_WORKER).
This allows any task that wants to be a user space task that only runs
in kernel mode to use this functionality.
The code on x86 is an exception and still retains a PF_KTHREAD test
because x86 unlikely everything else handles kthreads slightly
differently than user space tasks that start with a function.
The functions that created tasks that start with a function
have been updated to set ".fn" and ".fn_arg" instead of
".stack" and ".stack_size". These functions are fork_idle(),
create_io_thread(), kernel_thread(), and user_mode_thread().
Link: https://lkml.kernel.org/r/20220506141512.516114-4-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The architectures ia64 and parisc have special handling for the idle
thread in copy_process. Add a flag named idle to kernel_clone_args
and use it to explicity test if an idle process is being created.
Fullfill the expectations of the rest of the copy_thread
implemetations and pass a function pointer in .stack from fork_idle().
This makes what is happening in copy_thread better defined, and is
useful to make idle threads less special.
Link: https://lkml.kernel.org/r/20220506141512.516114-3-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
With io_uring we have started supporting tasks that are for most
purposes user space tasks that exclusively run code in kernel mode.
The kernel task that exec's init and tasks that exec user mode
helpers are also user mode tasks that just run kernel code
until they call kernel execve.
Pass kernel_clone_args into copy_thread so these oddball
tasks can be supported more cleanly and easily.
v2: Fix spelling of kenrel_clone_args on h8300
Link: https://lkml.kernel.org/r/20220506141512.516114-2-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
