powerpc: Fix VSCR position in ucontext (bug 24088)

This patch fix VSCR position on ucontext. VSCR was read in the wrong
position on ucontext structure because it was ignoring the machine
endianess.

	[BZ #24088]
	* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h (vscr_t): Added
	ifdef to fix read of VSCR.
	* sysdeps/powerpc/powerpc64/Makefile [$subdir == stdlib]: Add
	tst-ucontext-ppc64-vscr.c to test list.
	* sysdeps/powerpc/powerpc64/tst-ucontext-ppc64-vscr.c: New test file.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>

diff --git a/ChangeLog b/ChangeLog
index c640abcc9d6a6d26ac18271127273760db051f4b..61703793258bfb26b754d7cd4d8627cf19a72e77 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2019-01-11  Rogerio A. Cardoso  <rcardoso@linux.ibm.com>
+
+       * sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h (vscr_t): Added
+       ifdef to fix read of VSCR.
+       * sysdeps/powerpc/powerpc64/Makefile [$subdir == stdlib]: Add
+       tst-ucontext-ppc64-vscr.c to test list.
+       * sysdeps/powerpc/powerpc64/tst-ucontext-ppc64-vscr.c: New test file.
+
 2019-01-10  Andreas K. Hüttel  <dilfridge@gentoo.org>
 
        * resolv/tst-resolv-ai_idn-common.c (response): Avoid switch

diff --git a/sysdeps/powerpc/powerpc64/Makefile b/sysdeps/powerpc/powerpc64/Makefile
index a0bd0c9504270a8767be0ccb0f4d398a95b43420..6e88df1d6968212b5b15d093e77a5f69fbc3ce18 100644 (file)
--- a/sysdeps/powerpc/powerpc64/Makefile
+++ b/sysdeps/powerpc/powerpc64/Makefile
@@ -59,3 +59,8 @@ $(objpfx)tst-setjmp-bug21895-static.out: $(objpfx)setjmp-bug21895.so
 tst-setjmp-bug21895-static-ENV = \
        LD_LIBRARY_PATH=$(objpfx):$(common-objpfx):$(common-objpfx)setjmp:$(common-objpfx)elf
 endif
+
+ifeq ($(subdir),stdlib)
+CFLAGS-tst-ucontext-ppc64-vscr.c += -maltivec
+tests += tst-ucontext-ppc64-vscr
+endif

diff --git a/sysdeps/powerpc/powerpc64/tst-ucontext-ppc64-vscr.c b/sysdeps/powerpc/powerpc64/tst-ucontext-ppc64-vscr.c
new file mode 100644 (file)
index 0000000..2dcf5bb
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/tst-ucontext-ppc64-vscr.c
@@ -0,0 +1,84 @@
+/* Test if POWER vscr read by ucontext.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/check.h>
+#include <sys/auxv.h>
+#include <ucontext.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <altivec.h>
+
+#define SAT 0x1
+
+/* This test is supported only on POWER 5 or higher.  */
+#define PPC_CPU_SUPPORTED (PPC_FEATURE_POWER5 | PPC_FEATURE_POWER5_PLUS | \
+                          PPC_FEATURE_ARCH_2_05 | PPC_FEATURE_ARCH_2_06 | \
+                          PPC_FEATURE2_ARCH_2_07)
+static int
+do_test (void)
+{
+
+  if (!(getauxval(AT_HWCAP2) & PPC_CPU_SUPPORTED))
+    {
+      if (!(getauxval(AT_HWCAP) & PPC_CPU_SUPPORTED))
+      FAIL_UNSUPPORTED("This test is unsupported on POWER < 5\n");
+    }
+
+  uint32_t vscr[4] __attribute__ ((aligned (16)));
+  uint32_t* vscr_ptr = vscr;
+  uint32_t vscr_word;
+  ucontext_t ucp;
+  __vector __int128_t v0 = {0};
+  __vector __int128_t v1 = {0};
+
+  /* Set SAT bit in VSCR register.  */
+  asm volatile (".machine push;\n"
+               ".machine \"power5\";\n"
+               "vspltisb %0,0;\n"
+               "vspltisb %1,-1;\n"
+               "vpkuwus %0,%0,%1;\n"
+               "mfvscr %0;\n"
+               "stvx %0,0,%2;\n"
+               ".machine pop;"
+               : "=v" (v0), "=v" (v1)
+               : "r" (vscr_ptr)
+               : "memory");
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+  vscr_word = vscr[0];
+#else
+  vscr_word = vscr[3];
+#endif
+
+  if ((vscr_word & SAT) != SAT)
+    {
+      FAIL_EXIT1("FAIL: SAT bit is not set.\n");
+    }
+
+  if (getcontext (&ucp))
+    {
+      FAIL_EXIT1("FAIL: getcontext error\n");
+    }
+  if (ucp.uc_mcontext.v_regs->vscr.vscr_word != vscr_word)
+    {
+      FAIL_EXIT1("FAIL: ucontext vscr does not match with vscr\n");
+    }
+  return 0;
+}
+
+#include <support/test-driver.c>

diff --git a/sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h b/sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h
index ccd49928068e70f695a0e5a36b3c0c8e88d23a26..95142401a3792104e138dacf7f78f463fa995c8c 100644 (file)
--- a/sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h
+++ b/sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h
@@ -98,8 +98,13 @@ typedef double fpregset_t[__NFPREG];
    a whole quadword speedup save/restore.  */
 typedef struct _libc_vscr
 {
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
        unsigned int __pad[3];
        unsigned int __ctx(vscr_word);
+#else
+       unsigned int __ctx(vscr_word);
+       unsigned int __pad[3];
+#endif
 } vscr_t;
 
 /* Container for Altivec/VMX registers and status.