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Mon, 5 Feb 2024 15:48:46 GMT Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CC41320043; Mon, 5 Feb 2024 15:48:45 +0000 (GMT) Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 969962004D; Mon, 5 Feb 2024 15:48:45 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by smtpav03.fra02v.mail.ibm.com (Postfix) with ESMTP; Mon, 5 Feb 2024 15:48:45 +0000 (GMT) From: Heiko Carstens To: Kees Cook , Nathan Chancellor , Nick Desaulniers Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, Vasily Gorbik , Alexander Gordeev Subject: [PATCH 2/2] s390/fpu: make use of __uninitialized macro Date: Mon, 5 Feb 2024 16:48:44 +0100 Message-Id: <20240205154844.3757121-3-hca@linux.ibm.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240205154844.3757121-1-hca@linux.ibm.com> References: <20240205154844.3757121-1-hca@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-GUID: sTRo0zi2J2zYRPUPIc8TYQ-XRqG4f-Gh X-Proofpoint-ORIG-GUID: jgcjCb9p1o1Bo_dS6_KzVs51MqdBDXpP X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.1011,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2024-02-05_10,2024-01-31_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 impostorscore=0 phishscore=0 mlxscore=0 malwarescore=0 suspectscore=0 lowpriorityscore=0 adultscore=0 clxscore=1015 mlxlogscore=999 priorityscore=1501 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311290000 definitions=main-2402050119 Content-Type: text/plain; charset="utf-8" Code sections in s390 specific kernel code which use floating point or vector registers all come with a 520 byte stack variable to save already in use registers, if required. With INIT_STACK_ALL_PATTERN or INIT_STACK_ALL_ZERO enabled this variable will always be initialized on function entry in addition to saving register contents, which contradicts the intend (performance improvement) of such code sections. Therefore provide a DECLARE_KERNEL_FPU_ONSTACK() macro which provides struct kernel_fpu variables with an __uninitialized attribute, and convert all existing code to use this. This way only this specific type of stack variable will not be initialized, regardless of config options. Signed-off-by: Heiko Carstens Reviewed-by: Kees Cook Reviewed-by: Nathan Chancellor --- arch/s390/crypto/chacha-glue.c | 2 +- arch/s390/crypto/crc32-vx.c | 2 +- arch/s390/include/asm/fpu/types.h | 3 +++ arch/s390/kernel/sysinfo.c | 2 +- lib/raid6/s390vx.uc | 4 ++-- 5 files changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/s390/crypto/chacha-glue.c b/arch/s390/crypto/chacha-glue.c index ed9959e6f714..a823132fc563 100644 --- a/arch/s390/crypto/chacha-glue.c +++ b/arch/s390/crypto/chacha-glue.c @@ -22,7 +22,7 @@ static void chacha20_crypt_s390(u32 *state, u8 *dst, cons= t u8 *src, unsigned int nbytes, const u32 *key, u32 *counter) { - struct kernel_fpu vxstate; + DECLARE_KERNEL_FPU_ONSTACK(vxstate); =20 kernel_fpu_begin(&vxstate, KERNEL_VXR); chacha20_vx(dst, src, nbytes, key, counter); diff --git a/arch/s390/crypto/crc32-vx.c b/arch/s390/crypto/crc32-vx.c index 017143e9cef7..6ae3e3ff5b0a 100644 --- a/arch/s390/crypto/crc32-vx.c +++ b/arch/s390/crypto/crc32-vx.c @@ -49,8 +49,8 @@ u32 crc32c_le_vgfm_16(u32 crc, unsigned char const *buf, = size_t size); static u32 __pure ___fname(u32 crc, \ unsigned char const *data, size_t datalen) \ { \ - struct kernel_fpu vxstate; \ unsigned long prealign, aligned, remaining; \ + DECLARE_KERNEL_FPU_ONSTACK(vxstate); \ \ if (datalen < VX_MIN_LEN + VX_ALIGN_MASK) \ return ___crc32_sw(crc, data, datalen); \ diff --git a/arch/s390/include/asm/fpu/types.h b/arch/s390/include/asm/fpu/= types.h index d889e9436865..b1afa13c07b7 100644 --- a/arch/s390/include/asm/fpu/types.h +++ b/arch/s390/include/asm/fpu/types.h @@ -35,4 +35,7 @@ struct kernel_fpu { }; }; =20 +#define DECLARE_KERNEL_FPU_ONSTACK(name) \ + struct kernel_fpu name __uninitialized + #endif /* _ASM_S390_FPU_TYPES_H */ diff --git a/arch/s390/kernel/sysinfo.c b/arch/s390/kernel/sysinfo.c index f6f8f498c9be..b439f17516eb 100644 --- a/arch/s390/kernel/sysinfo.c +++ b/arch/s390/kernel/sysinfo.c @@ -426,9 +426,9 @@ subsys_initcall(create_proc_service_level); */ void s390_adjust_jiffies(void) { + DECLARE_KERNEL_FPU_ONSTACK(fpu); struct sysinfo_1_2_2 *info; unsigned long capability; - struct kernel_fpu fpu; =20 info =3D (void *) get_zeroed_page(GFP_KERNEL); if (!info) diff --git a/lib/raid6/s390vx.uc b/lib/raid6/s390vx.uc index cd0b9e95f499..7b0b355e1a26 100644 --- a/lib/raid6/s390vx.uc +++ b/lib/raid6/s390vx.uc @@ -81,7 +81,7 @@ static inline void COPY_VEC(int x, int y) =20 static void raid6_s390vx$#_gen_syndrome(int disks, size_t bytes, void **pt= rs) { - struct kernel_fpu vxstate; + DECLARE_KERNEL_FPU_ONSTACK(vxstate); u8 **dptr, *p, *q; int d, z, z0; =20 @@ -114,7 +114,7 @@ static void raid6_s390vx$#_gen_syndrome(int disks, size= _t bytes, void **ptrs) static void raid6_s390vx$#_xor_syndrome(int disks, int start, int stop, size_t bytes, void **ptrs) { - struct kernel_fpu vxstate; + DECLARE_KERNEL_FPU_ONSTACK(vxstate); u8 **dptr, *p, *q; int d, z, z0; =20 --=20 2.40.1