From 33b5495e1b6b1da44cf3218811cc2efdff46b961 Mon Sep 17 00:00:00 2001 From: Mark Vitale Date: Tue, 28 Feb 2017 18:02:39 -0500 Subject: [PATCH] SOLARIS: prevent BAD TRAP panic with Studio 12.5 Starting with Solaris Studio 12.3, it is documented that Solaris kernel modules (such as libafs) must not use any floating point, vector, or SIMD/SSE instructions on x86 hardware. However, each new Studio compiler release (12.4 and especially 12.5) is more likely to use these types of instructions by default. If the libafs kernel module includes any forbidden kernel instructions, Solaris will panic the system with: BAD TRAP: type=7 (#nm Device not available) Provide a new autoconfig test to specify the required compiler options (-xvector=%none -xregs=no%float) when building the OpenAFS kernel module for Solaris, so that no invalid x86 instructions are used. In addition, reinstate default kernel module optimization for Solaris. It had been disabled in commit 80592c53cbb0bce782eb39a5e64860786654be9f to address this same issue in Studio 12.3 and 12.4. However, Studio 12.5 started using some SSE instructions even with no optimization. This commit has been tested with OpenAFS master and Studio 12.5 at all optimization levels (none, -xO1 through -xO5) and verified to contain no XMM register instructions via the following command: $ gobjdump -dlr libafs64.o | grep xmm | wc -l [wiesand: limit change to solaris 5.11 for stable branch] Reviewed-on: https://gerrit.openafs.org/12558 Tested-by: BuildBot Reviewed-by: Benjamin Kaduk (cherry picked from commit 22d841a45fff7026318b529a41dd957ce8bb0ddf) Change-Id: I2e87f26dbac47289694346639b396dfc556368f4 Reviewed-on: https://gerrit.openafs.org/12567 Reviewed-by: Mark Vitale Tested-by: BuildBot Reviewed-by: Benjamin Kaduk Reviewed-by: Stephan Wiesand --- acinclude.m4 | 2 ++ src/cf/osconf.m4 | 11 ++++++--- src/cf/solaris-test1.m4 | 38 +++++++++++++++++++++++++++++ src/libafs/MakefileProto.SOLARIS.in | 2 +- 4 files changed, 48 insertions(+), 5 deletions(-) create mode 100644 src/cf/solaris-test1.m4 diff --git a/acinclude.m4 b/acinclude.m4 index 4b521c434..53ffcc567 100644 --- a/acinclude.m4 +++ b/acinclude.m4 @@ -387,6 +387,8 @@ case $system in MKAFS_OSTYPE=SOLARIS AC_MSG_RESULT(sun4) SOLARIS_PATH_CC + SOLARIS_CC_TAKES_XVECTOR_NONE + AC_SUBST(SOLARIS_CC_KOPTS) SOLARIS_UFSVFS_HAS_DQRWLOCK SOLARIS_FS_HAS_FS_ROLLED SOLARIS_SOLOOKUP_TAKES_SOCKPARAMS diff --git a/src/cf/osconf.m4 b/src/cf/osconf.m4 index 964e4742f..2fee044fd 100644 --- a/src/cf/osconf.m4 +++ b/src/cf/osconf.m4 @@ -716,6 +716,7 @@ case $AFS_SYSNAME in MT_CC=$SOLARISCC MT_CFLAGS='-mt -DAFS_PTHREAD_ENV ${XCFLAGS}' MT_LIBS="-lpthread -lsocket" + KERN_OPTMZ="-xO3" PAM_CFLAGS="-KPIC" PAM_LIBS="-lc -lpam -lsocket -lnsl -lm" SHLIB_CFLAGS="-KPIC" @@ -736,10 +737,12 @@ if test "x$enable_optimize_kernel" = "x" ; then AS_CASE([$AFS_SYSNAME], [sunx86_510|sunx86_511], dnl Somewhere around Solaris Studio 12.*, the compiler started adding SSE - dnl instructions to optimized code, without any ability to turn it off. - dnl So just default to not optimizing kernel code for the relevant - dnl platforms, until we get a better autoconf test for this. - [enable_optimize_kernel=no], + dnl instructions to optimized code, without any known way to turn it off. + dnl To cope, this condition was added to change the default to + dnl 'no'. + dnl Now that we have an autoconf test to allow disabling the SSE + dnl optimizations, it's safe to once more default to 'yes' here. + [enable_optimize_kernel=yes], [enable_optimize_kernel=yes]) fi diff --git a/src/cf/solaris-test1.m4 b/src/cf/solaris-test1.m4 new file mode 100644 index 000000000..a0b572ee2 --- /dev/null +++ b/src/cf/solaris-test1.m4 @@ -0,0 +1,38 @@ +dnl This test is for the Solaris x86 kernel module +dnl build. They prevent newer Solaris compilers (12.3 +dnl and up) from using XMM registers (SIMD instructions) +dnl and floating point registers, which are invalid in +dnl Solaris kernel code. +dnl Without this, Solaris may panic in libafs with: +dnl BAD TRAP: type=7 (#nm Device not available) +dnl +dnl +AC_DEFUN([SOLARIS_CC_TAKES_XVECTOR_NONE], [ + AC_CACHE_CHECK([if $CC accepts -xvector=%none], + [ac_cv_solaris_cc_takes_xvector_none], + [save_CFLAGS="$CFLAGS" + CFLAGS="$CFLAGS -xvector=%none" + AC_TRY_COMPILE([], + [int x;], + [ac_cv_solaris_cc_takes_xvector_none=yes], + [ac_cv_solaris_cc_takes_xvector_none=no]) + CFLAGS="$save_CFLAGS" + ]) + +dnl -xvector=%none first appeared in Studio 11, but has only been +dnl documented as required for Solaris x86 kernel code since Studio +dnl 12.3. Studio 12.3 is when the compiler started making more +dnl aggressive optimizations by using SSE/SIMD instructions with XMM +dnl (floating point/ SIMD) registers. Although -xvector=%none is +dnl required to prevent these optimizations, it is not sufficient. +dnl Experiments have shown that -xregs=no%float is also needed to +dnl 1) eliminate a few optimizations not squelched by -xvector=%none, +dnl and 2) prevent actual use of floating point types in the kernel +dnl module. -xregs=no%float has been present since before Studio 8, so +dnl it is safe to assume its presence when -xvector=%none is present. +dnl + + AS_IF([test "$ac_cv_solaris_cc_takes_xvector_none" = "yes"], + [SOLARIS_CC_KOPTS="-xvector=%none -xregs=no%float "]) +]) + diff --git a/src/libafs/MakefileProto.SOLARIS.in b/src/libafs/MakefileProto.SOLARIS.in index 121f77d9d..7432285d4 100644 --- a/src/libafs/MakefileProto.SOLARIS.in +++ b/src/libafs/MakefileProto.SOLARIS.in @@ -50,7 +50,7 @@ KDEFS_32 = KDEFS_64 = -xarch=amd64 -xmodel=kernel -CFLAGS=-I. -I.. -I${TOP_OBJDIR}/src/config ${FSINCLUDES} $(DEFINES) $(KDEFS) $(KOPTS) ${DBUG} +CFLAGS=-I. -I.. -I${TOP_OBJDIR}/src/config ${FSINCLUDES} $(DEFINES) $(KDEFS) @SOLARIS_CC_KOPTS@ ${DBUG} LDFLAGS=-r -dy -N drv/ip -N drv/udp -N strmod/rpcmod -- 2.39.5