[PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ

[Manjeet Pawar]

MINSIGSTKSZ and SIGSTKSZ for ARM64 are not correctly set in latest kernel.
This patch fixes this issue.

This issue is reported in LTP (testcase: sigaltstack02.c).
Testcase failed when sigaltstack() called with stack size "MINSIGSTKSZ - 1"
Since in Glibc-2.22, MINSIGSTKSZ is set to 5120 but in kernel
it is set to 2048 so testcase gets failed.

Testcase Output:
sigaltstack02 1  TPASS  :  stgaltstack() fails, Invalid Flag value,errno:22
sigaltstack02 2  TFAIL  :  sigaltstack() returned 0, expected -1,errno:12

Reported Issue in Glibc Bugzilla:
https://sourceware.org/bugzilla/show_bug.cgi?id=16850

Bugfix in Glibc-2.22:
https://sourceware.org/git/gitweb.cgi?p=glibc.git;a=blob;f=sysdeps/unix/
sysv/linux/aarch64/bits/sigstack.h;h=8f2fb76e3e81734ef8a9cf9ae40daf4705
f31c35;hb=b763f6ae859ecea70a5dacb8ad45c71d5f667e2e

Signed-off-by: Akhilesh Kumar <akhilesh.k at samsung.com>
Signed-off-by: Manjeet Pawar <manjeet.p at samsung.com>
Signed-off-by: Rohit Thapliyal <r.thapliyal at samsung.com>

---
v1 -> Changes in uapi overall header
v2 -> Changes done in arm64 headers

 arch/arm64/include/uapi/asm/signal.h |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/include/uapi/asm/signal.h b/arch/arm64/include/uapi/asm/signal.h
index 8d1e723..5ac56cf 100644
--- a/arch/arm64/include/uapi/asm/signal.h
+++ b/arch/arm64/include/uapi/asm/signal.h
@@ -21,4 +21,9 @@
 
 #include <asm-generic/signal.h>
 
+#undef MINSIGSTKSZ
+#undef SIGSTKSZ
+#define MINSIGSTKSZ 5120
+#define SIGSTKSZ    16384
+
 #endif
-- 
1.7.9.5