Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 29 3月, 2019 10 次提交
  3. 23 3月, 2019 2 次提交
  5. 22 3月, 2019 1 次提交
    • V
      x86/mm/pti: Make local symbols static · 4fe64a62
      由 Valdis Kletnieks 提交于 
      With 'make C=2 W=1', sparse and gcc both complain:

  CHECK   arch/x86/mm/pti.c
arch/x86/mm/pti.c:84:3: warning: symbol 'pti_mode' was not declared. Should it be static?
arch/x86/mm/pti.c:605:6: warning: symbol 'pti_set_kernel_image_nonglobal' was not declared. Should it be static?
  CC      arch/x86/mm/pti.o
arch/x86/mm/pti.c:605:6: warning: no previous prototype for 'pti_set_kernel_image_nonglobal' [-Wmissing-prototypes]
  605 | void pti_set_kernel_image_nonglobal(void)
      |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

pti_set_kernel_image_nonglobal() is only used locally. 'pti_mode' exists in
drivers/hwtracing/intel_th/pti.c as well, but it's a completely unrelated
local (static) symbol.

Make both static.
Signed-off-by: NValdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/27680.1552376873@turing-police
      4fe64a62
  7. 21 3月, 2019 9 次提交
  9. 20 3月, 2019 1 次提交
    • B
      powerpc/mm: Only define MAX_PHYSMEM_BITS in SPARSEMEM configurations · 8bc08689
      由 Ben Hutchings 提交于 
      MAX_PHYSMEM_BITS only needs to be defined if CONFIG_SPARSEMEM is
enabled, and that was the case before commit 4ffe713b
("powerpc/mm: Increase the max addressable memory to 2PB").

On 32-bit systems, where CONFIG_SPARSEMEM is not enabled, we now
define it as 46.  That is larger than the real number of physical
address bits, and breaks calculations in zsmalloc:

  mm/zsmalloc.c:130:49: warning: right shift count is negative
    MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS))
                                                   ^~
  ...
  mm/zsmalloc.c:253:21: error: variably modified 'size_class' at file scope
    struct size_class *size_class[ZS_SIZE_CLASSES];
                       ^~~~~~~~~~

Fixes: 4ffe713b ("powerpc/mm: Increase the max addressable memory to 2PB")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      8bc08689
  11. 19 3月, 2019 9 次提交
  13. 18 3月, 2019 2 次提交
    • C
      powerpc/6xx: fix setup and use of SPRN_SPRG_PGDIR for hash32 · 4622a2d4
      由 Christophe Leroy 提交于 
      Not only the 603 but all 6xx need SPRN_SPRG_PGDIR to be initialised at
startup. This patch move it from __setup_cpu_603() to start_here()
and __secondary_start(), close to the initialisation of SPRN_THREAD.

Previously, virt addr of PGDIR was retrieved from thread struct.
Now that it is the phys addr which is stored in SPRN_SPRG_PGDIR,
hash_page() shall not convert it to phys anymore.
This patch removes the conversion.

Fixes: 93c4a162 ("powerpc/6xx: Store PGDIR physical address in a SPRG")
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      4622a2d4
    • M
      powerpc/vdso64: Fix CLOCK_MONOTONIC inconsistencies across Y2038 · b5b4453e
      由 Michael Ellerman 提交于 
      Jakub Drnec reported:
  Setting the realtime clock can sometimes make the monotonic clock go
  back by over a hundred years. Decreasing the realtime clock across
  the y2k38 threshold is one reliable way to reproduce. Allegedly this
  can also happen just by running ntpd, I have not managed to
  reproduce that other than booting with rtc at >2038 and then running
  ntp. When this happens, anything with timers (e.g. openjdk) breaks
  rather badly.

And included a test case (slightly edited for brevity):
  #define _POSIX_C_SOURCE 199309L
  #include <stdio.h>
  #include <time.h>
  #include <stdlib.h>
  #include <unistd.h>

  long get_time(void) {
    struct timespec tp;
    clock_gettime(CLOCK_MONOTONIC, &tp);
    return tp.tv_sec + tp.tv_nsec / 1000000000;
  }

  int main(void) {
    long last = get_time();
    while(1) {
      long now = get_time();
      if (now < last) {
        printf("clock went backwards by %ld seconds!\n", last - now);
      }
      last = now;
      sleep(1);
    }
    return 0;
  }

Which when run concurrently with:
 # date -s 2040-1-1
 # date -s 2037-1-1

Will detect the clock going backward.

The root cause is that wtom_clock_sec in struct vdso_data is only a
32-bit signed value, even though we set its value to be equal to
tk->wall_to_monotonic.tv_sec which is 64-bits.

Because the monotonic clock starts at zero when the system boots the
wall_to_montonic.tv_sec offset is negative for current and future
dates. Currently on a freshly booted system the offset will be in the
vicinity of negative 1.5 billion seconds.

However if the wall clock is set past the Y2038 boundary, the offset
from wall to monotonic becomes less than negative 2^31, and no longer
fits in 32-bits. When that value is assigned to wtom_clock_sec it is
truncated and becomes positive, causing the VDSO assembly code to
calculate CLOCK_MONOTONIC incorrectly.

That causes CLOCK_MONOTONIC to jump ahead by ~4 billion seconds which
it is not meant to do. Worse, if the time is then set back before the
Y2038 boundary CLOCK_MONOTONIC will jump backward.

We can fix it simply by storing the full 64-bit offset in the
vdso_data, and using that in the VDSO assembly code. We also shuffle
some of the fields in vdso_data to avoid creating a hole.

The original commit that added the CLOCK_MONOTONIC support to the VDSO
did actually use a 64-bit value for wtom_clock_sec, see commit
a7f290da ("[PATCH] powerpc: Merge vdso's and add vdso support to
32 bits kernel") (Nov 2005). However just 3 days later it was
converted to 32-bits in commit 0c37ec2a ("[PATCH] powerpc: vdso
fixes (take #2)"), and the bug has existed since then AFAICS.

Fixes: 0c37ec2a ("[PATCH] powerpc: vdso fixes (take #2)")
Cc: stable@vger.kernel.org # v2.6.15+
Link: http://lkml.kernel.org/r/HaC.ZfES.62bwlnvAvMP.1STMMj@seznam.czReported-by: NJakub Drnec <jaydee@email.cz>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      b5b4453e
  15. 17 3月, 2019 3 次提交
  17. 16 3月, 2019 3 次提交