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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Fri, 12 Jul 2019 14:09:15 +0100 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x6CD9Ewu50593952 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 12 Jul 2019 13:09:14 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2CD22A4051; Fri, 12 Jul 2019 13:09:14 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9E5F0A405B; Fri, 12 Jul 2019 13:09:13 +0000 (GMT) Received: from oc2783563651 (unknown [9.152.224.222]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 12 Jul 2019 13:09:13 +0000 (GMT) Date: Fri, 12 Jul 2019 15:09:12 +0200 From: Halil Pasic To: Thiago Jung Bauermann Subject: Re: [PATCH 3/3] fs/core/vmcore: Move sev_active() reference to x86 arch code In-Reply-To: <20190712053631.9814-4-bauerman@linux.ibm.com> References: <20190712053631.9814-1-bauerman@linux.ibm.com> <20190712053631.9814-4-bauerman@linux.ibm.com> Organization: IBM X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.31; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19071213-0012-0000-0000-000003321AC7 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19071213-0013-0000-0000-0000216B8B35 Message-Id: <20190712150912.3097215e.pasic@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-07-12_04:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907120143 X-Mailman-Approved-At: Sat, 13 Jul 2019 18:44:21 +1000 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-s390@vger.kernel.org, Mike Anderson , Konrad Rzeszutek Wilk , Robin Murphy , x86@kernel.org, Ram Pai , linux-kernel@vger.kernel.org, Alexey Dobriyan , iommu@lists.linux-foundation.org, Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , linux-fsdevel@vger.kernel.org, Thomas Gleixner , linuxppc-dev@lists.ozlabs.org, Christoph Hellwig , Marek Szyprowski Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Fri, 12 Jul 2019 02:36:31 -0300 Thiago Jung Bauermann wrote: > Secure Encrypted Virtualization is an x86-specific feature, so it shouldn't > appear in generic kernel code because it forces non-x86 architectures to > define the sev_active() function, which doesn't make a lot of sense. sev_active() might be just bad (too specific) name for a general concept. s390 code defines it drives the right behavior in kernel/dma/direct.c (which uses it). > > To solve this problem, add an x86 elfcorehdr_read() function to override > the generic weak implementation. To do that, it's necessary to make > read_from_oldmem() public so that it can be used outside of vmcore.c. > > Signed-off-by: Thiago Jung Bauermann > --- > arch/x86/kernel/crash_dump_64.c | 5 +++++ > fs/proc/vmcore.c | 8 ++++---- > include/linux/crash_dump.h | 14 ++++++++++++++ > include/linux/mem_encrypt.h | 1 - > 4 files changed, 23 insertions(+), 5 deletions(-) Does not seem to apply to today's or yesterdays master. > > diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c > index 22369dd5de3b..045e82e8945b 100644 > --- a/arch/x86/kernel/crash_dump_64.c > +++ b/arch/x86/kernel/crash_dump_64.c > @@ -70,3 +70,8 @@ ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize, > { > return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, true); > } > + > +ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos) > +{ > + return read_from_oldmem(buf, count, ppos, 0, sev_active()); > +} > diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c > index 57957c91c6df..ca1f20bedd8c 100644 > --- a/fs/proc/vmcore.c > +++ b/fs/proc/vmcore.c > @@ -100,9 +100,9 @@ static int pfn_is_ram(unsigned long pfn) > } > > /* Reads a page from the oldmem device from given offset. */ > -static ssize_t read_from_oldmem(char *buf, size_t count, > - u64 *ppos, int userbuf, > - bool encrypted) > +ssize_t read_from_oldmem(char *buf, size_t count, > + u64 *ppos, int userbuf, > + bool encrypted) > { > unsigned long pfn, offset; > size_t nr_bytes; > @@ -166,7 +166,7 @@ void __weak elfcorehdr_free(unsigned long long addr) > */ > ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos) > { > - return read_from_oldmem(buf, count, ppos, 0, sev_active()); > + return read_from_oldmem(buf, count, ppos, 0, false); > } > > /* > diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h > index f774c5eb9e3c..4664fc1871de 100644 > --- a/include/linux/crash_dump.h > +++ b/include/linux/crash_dump.h > @@ -115,4 +115,18 @@ static inline int vmcore_add_device_dump(struct vmcoredd_data *data) > return -EOPNOTSUPP; > } > #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ > + > +#ifdef CONFIG_PROC_VMCORE > +ssize_t read_from_oldmem(char *buf, size_t count, > + u64 *ppos, int userbuf, > + bool encrypted); > +#else > +static inline ssize_t read_from_oldmem(char *buf, size_t count, > + u64 *ppos, int userbuf, > + bool encrypted) > +{ > + return -EOPNOTSUPP; > +} > +#endif /* CONFIG_PROC_VMCORE */ > + > #endif /* LINUX_CRASHDUMP_H */ > diff --git a/include/linux/mem_encrypt.h b/include/linux/mem_encrypt.h > index f2e399fb626b..a3747fcae466 100644 > --- a/include/linux/mem_encrypt.h > +++ b/include/linux/mem_encrypt.h > @@ -21,7 +21,6 @@ > > #else /* !CONFIG_ARCH_HAS_MEM_ENCRYPT */ > > -static inline bool sev_active(void) { return false; } This is the implementation for the guys that don't have ARCH_HAS_MEM_ENCRYPT. Means sev_active() may not be used in such code after this patch. What about static inline bool force_dma_unencrypted(void) { return sev_active(); } in kernel/dma/direct.c? Regards, Halil > static inline bool mem_encrypt_active(void) { return false; } > > #endif /* CONFIG_ARCH_HAS_MEM_ENCRYPT */