[COMMIT osv master] aarch64: increase exception stack size to 64K

[Commit Bot]

From: Waldemar Kozaczuk <jwkoz...@gmail.com>
Committer: Waldemar Kozaczuk <jwkoz...@gmail.com>
Branch: master

aarch64: increase exception stack size to 64K

On aarch64 the syscalls are handled on the exception stack. And some of
the syscalls involving vfs may end up consuming more then 16K
of stack. A good example of it is a namei() function that needs
a minimum of 8K of stack. The tst-symlink test involves syscalls
that need more than 32K.

In order to prevent corruption of thread structures we need to
increase the exception stack size to 64K which is the same as
the x64 syscall stack size.

Signed-off-by: Waldemar Kozaczuk <jwkoz...@gmail.com>

---
diff --git a/arch/aarch64/arch-cpu.hh b/arch/aarch64/arch-cpu.hh
--- a/arch/aarch64/arch-cpu.hh
+++ b/arch/aarch64/arch-cpu.hh
@@ -33,7 +33,7 @@ struct arch_cpu {
};

struct arch_thread {
- char exception_stack[4096*4] __attribute__((aligned(16)));
+ char exception_stack[4096*16] __attribute__((aligned(16)));
};

struct arch_fpu {