From: Christoph Hellwig <hch@lst.de> To: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>, Vincenzo Frascino <Vincenzo.Frascino@arm.com>, Kevin Brodsky <kevin.brodsky@arm.com>, linux-fsdevel <linux-fsdevel@vger.kernel.org>, kexec <kexec@lists.infradead.org>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, Dave Young <dyoung@redhat.com>, Baoquan He <bhe@redhat.com>, Vivek Goyal <vgoyal@redhat.com>, x86 <x86@kernel.org> Subject: Re: [RFC PATCH 01/14] fs/proc/vmcore: Update read_from_oldmem() for user pointer Date: Mon, 6 Dec 2021 15:04:51 +0100 [thread overview] Message-ID: <20211206140451.GA4936@lst.de> (raw) In-Reply-To: <20211203104231.17597-2-amit.kachhap@arm.com> On Fri, Dec 03, 2021 at 04:12:18PM +0530, Amit Daniel Kachhap wrote: > + return read_from_oldmem_to_kernel(buf, count, ppos, > + cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)); Overly long line. > +ssize_t read_from_oldmem(char __user *ubuf, char *kbuf, size_t count, > + u64 *ppos, bool encrypted) > { > unsigned long pfn, offset; > size_t nr_bytes; > @@ -156,19 +163,27 @@ ssize_t read_from_oldmem(char *buf, size_t count, > /* If pfn is not ram, return zeros for sparse dump files */ > if (!pfn_is_ram(pfn)) { > tmp = 0; > - if (!userbuf) > - memset(buf, 0, nr_bytes); > - else if (clear_user(buf, nr_bytes)) > + if (kbuf) > + memset(kbuf, 0, nr_bytes); > + else if (clear_user(ubuf, nr_bytes)) > tmp = -EFAULT; This looks like a huge mess. What speak against using an iov_iter here?
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de> To: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>, Vincenzo Frascino <Vincenzo.Frascino@arm.com>, Kevin Brodsky <kevin.brodsky@arm.com>, linux-fsdevel <linux-fsdevel@vger.kernel.org>, kexec <kexec@lists.infradead.org>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, Dave Young <dyoung@redhat.com>, Baoquan He <bhe@redhat.com>, Vivek Goyal <vgoyal@redhat.com>, x86 <x86@kernel.org> Subject: Re: [RFC PATCH 01/14] fs/proc/vmcore: Update read_from_oldmem() for user pointer Date: Mon, 6 Dec 2021 15:04:51 +0100 [thread overview] Message-ID: <20211206140451.GA4936@lst.de> (raw) In-Reply-To: <20211203104231.17597-2-amit.kachhap@arm.com> On Fri, Dec 03, 2021 at 04:12:18PM +0530, Amit Daniel Kachhap wrote: > + return read_from_oldmem_to_kernel(buf, count, ppos, > + cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)); Overly long line. > +ssize_t read_from_oldmem(char __user *ubuf, char *kbuf, size_t count, > + u64 *ppos, bool encrypted) > { > unsigned long pfn, offset; > size_t nr_bytes; > @@ -156,19 +163,27 @@ ssize_t read_from_oldmem(char *buf, size_t count, > /* If pfn is not ram, return zeros for sparse dump files */ > if (!pfn_is_ram(pfn)) { > tmp = 0; > - if (!userbuf) > - memset(buf, 0, nr_bytes); > - else if (clear_user(buf, nr_bytes)) > + if (kbuf) > + memset(kbuf, 0, nr_bytes); > + else if (clear_user(ubuf, nr_bytes)) > tmp = -EFAULT; This looks like a huge mess. What speak against using an iov_iter here? _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2021-12-06 14:05 UTC|newest] Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-12-03 10:42 [RFC PATCH 00/14] fs/proc/vmcore: Remove unnecessary user pointer conversions Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` [RFC PATCH 01/14] fs/proc/vmcore: Update read_from_oldmem() for user pointer Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-06 14:04 ` Christoph Hellwig [this message] 2021-12-06 14:04 ` Christoph Hellwig 2021-12-06 14:17 ` Matthew Wilcox 2021-12-06 14:17 ` Matthew Wilcox 2021-12-06 14:54 ` Christoph Hellwig 2021-12-06 14:54 ` Christoph Hellwig 2021-12-06 15:07 ` Matthew Wilcox 2021-12-06 15:07 ` Matthew Wilcox 2021-12-07 11:15 ` Christoph Hellwig 2021-12-07 11:15 ` Christoph Hellwig 2021-12-07 7:11 ` Amit Kachhap 2021-12-07 7:11 ` Amit Kachhap 2021-12-03 10:42 ` [RFC PATCH 02/14] fs/proc/vmcore: Update copy_oldmem_page_encrypted() for user buffer Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` [RFC PATCH 03/14] fs/proc/vmcore: Update copy_oldmem_page() " Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` [RFC PATCH 04/14] x86/crash_dump_64: Use the new interface copy_oldmem_page_buf Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` [RFC PATCH 05/14] x86/crash_dump_32: " Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` [RFC PATCH 06/14] arm64/crash_dump: " Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` [RFC PATCH 07/14] arm/crash_dump: " Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` [RFC PATCH 08/14] mips/crash_dump: " Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` [RFC PATCH 09/14] sh/crash_dump: " Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` [RFC PATCH 10/14] riscv/crash_dump: " Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` [RFC PATCH 11/14] powerpc/crash_dump: " Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` [RFC PATCH 12/14] ia64/crash_dump: " Amit Daniel Kachhap 2021-12-03 10:54 ` Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` [RFC PATCH 13/14] s390/crash_dump: " Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap 2021-12-03 10:42 ` [RFC PATCH 14/14] fs/proc/vmcore: Remove the unused old interface copy_oldmem_page Amit Daniel Kachhap 2021-12-03 10:42 ` Amit Daniel Kachhap
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