On 2016/02/29 05:53PM, Cyril Bur wrote:

quoted

Cover-letter for V1 of the series is at
https://lists.ozlabs.org/pipermail/linuxppc-dev/2015-November/136350.html

Cover-letter for V2 of the series is at
https://lists.ozlabs.org/pipermail/linuxppc-dev/2016-January/138054.html

Changes in V3:
Addressed review comments from Michael Neuling
 - Made commit message in 4/9 better reflect the patch
 - Removed overuse of #ifdef blocks and redundant condition in 5/9
 - Split 6/8 in two to better prepare for 7,8,9
 - Removed #ifdefs in 6/9

Changes in V4:
 - Addressed non ABI compliant ASM macros in 1/9
 - Fixed build breakage due to changing #ifdefs in V3 (6/9)
 - Reordered some conditions in if statements

Changes in V5:
 - Enhanced basic-asm.h to provide ABI independent macro as pointed out by
   Naveen Rao.
   - Tested for both BE and LE builds. Had to disable -flto from the
     selftests/powerpc Makefile as it didn't play well with the custom ASM.
 - Added some extra debugging output to the vmx_signal testcase
 - Fixed comments in testing code
 - Updated VSX test code to use GCC Altivec macros

Changes in V6:
 - Removed recursive definition of CFLAGS in math/Makefile
 - Corrected the use of the word param in favour of doubleword
 - Reordered some code in basic-asm.h and neatened some comments

This series is resulting in a kernel crash with one of the perf tests.  
To reproduce, build perf and run the test for breakpoint overflow signal 
handler.

# ./perf test -v 17
17: Test breakpoint overflow signal handler                  :

--- start ---

test child forked, pid 3753
failed opening event 0
failed opening event 0
cpu 0xd: Vector: 600 (Alignment) at [c0000000edd738c0]
    pc: c00000000000a818: save_fpu+0xa8/0x2ac
    lr: c00000000001568c: __giveup_fpu+0x2c/0x90
    sp: c0000000edd73b40
   msr: 800000000280b033
   dar: c0000000edc436e0
 dsisr: 42000000
  current = 0xc0000000edc42c00
  paca    = 0xc000000007e82700	 softe: 0	 irq_happened: 0x01
    pid   = 3753, comm = perf
Linux version 4.6.0-rc3-nnr+ (root@rhel71le) (gcc version 4.8.3 20140911 (Red Hat 4.8.3-8) (GCC) ) #93 SMP Wed May 4 22:01:06 IST 2016
enter ? for help
[link register   ] c00000000001568c __giveup_fpu+0x2c/0x90
[c0000000edd73b40] 0000000000000000 (unreliable)
[c0000000edd73b70] c000000000015730 giveup_fpu+0x40/0xa0
[c0000000edd73ba0] c000000000015810 flush_fp_to_thread+0x80/0x90
[c0000000edd73bd0] c000000000026b3c setup_sigcontext.constprop.3+0xbc/0x1f0
[c0000000edd73c30] c0000000000274c4 handle_rt_signal64+0x3b4/0x7c0
[c0000000edd73d10] c000000000017ee0 do_signal+0x150/0x2b0
[c0000000edd73e00] c000000000018220 do_notify_resume+0xd0/0x110
[c0000000edd73e30] c000000000009844 ret_from_except_lite+0x70/0x74

--- Exception: 900 (Decrementer) at 00000000100b3c88

SP (3fffd08cfb20) is in userspace
d:mon> ls save_fpu
save_fpu: c00000000000a770

With v4.5, the test would fail, but not cause what looks to be an 
alignment exception.