[PATCH] tcg/tci: Fix TCI on hppa host and update TCI test matrix

[Helge Deller <deller@kernel.org>]

Update the TCI interpreter test matrix for big-endian hosts with
big- (hppa, hppa64) and little-endian (x86,x96-64) targets.
I used native ppc64 and hppa hosts for those tests.

Starting TCI on a hppa host crashed immediately, because hppa is
the only archive left where the stack grows upwards.
Write-protecting the stack guard page at the top of the stack
fixes the crash.

Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/tcg/tci/README b/tcg/tci/README
index 4a8b5b5401..0c1e50779e 100644
--- a/tcg/tci/README
+++ b/tcg/tci/README
@@ -72,16 +72,16 @@ host and target with same or different endianness.
             | host (le)                     host (be)
             | 32             64             32             64
 ------------+------------------------------------------------------------
-target (le) | s0, u0         s1, u1         s?, u?         s?, u?
+target (le) | s0, u0         s1, u1         s2, u?         s2, u?
 32 bit      |
             |
-target (le) | sc, uc         s1, u1         s?, u?         s?, u?
+target (le) | sc, uc         s1, u1         s2, u?         s2, u?
 64 bit      |
             |
-target (be) | sc, u0         sc, uc         s?, u?         s?, u?
+target (be) | sc, u0         sc, uc         s2, u?         s2, u?
 32 bit      |
             |
-target (be) | sc, uc         sc, uc         s?, u?         s?, u?
+target (be) | sc, uc         sc, uc         s?, u?         s2, u?
 64 bit      |
             |
 
@@ -110,6 +115,10 @@ u1 = linux-user-test works
   A cross compiled QEMU for ppc host works at least partially:
   i386-linux-user/qemu-i386 can run a simple hello-world program
   (tested in a ppc emulation).
+  The big-endian tests were run on native hppa (big-endian, 32-bit) and
+  ppc64 (big-endian, 64-bit) machines. Tested target machines were
+  x86 and x86-64 (little-endian, debian install ISO) and 32- and 64-bit
+  big-endian hppa (NetBSD and Debian install ISOs).
 
 * Some TCG opcodes are either missing in the code generator and/or
   in the interpreter. These opcodes raise a runtime exception, so it is
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index e86fd64e09..e378b71641 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -585,11 +585,8 @@ char *qemu_get_pid_name(pid_t pid)
 
 void *qemu_alloc_stack(size_t *sz)
 {
-    void *ptr;
+    void *ptr, *ptr2;
     int flags;
-#ifdef CONFIG_DEBUG_STACK_USAGE
-    void *ptr2;
-#endif
     size_t pagesz = qemu_real_host_page_size();
 #ifdef _SC_THREAD_STACK_MIN
     /* avoid stacks smaller than _SC_THREAD_STACK_MIN */
@@ -619,7 +616,12 @@ void *qemu_alloc_stack(size_t *sz)
     }
 
     /* Stack grows down -- guard page at the bottom. */
-    if (mprotect(ptr, pagesz, PROT_NONE) != 0) {
+    ptr2 = ptr;
+#if defined(__hppa__)
+    /* but on hppa the stack grows up, so guard the top page instead */
+    ptr2 = ptr + *sz - pagesz;
+#endif
+    if (mprotect(ptr2, pagesz, PROT_NONE) != 0) {
         perror("failed to set up stack guard page");
         abort();
     }