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?
next prev parent reply other threads:[~2021-12-06 14:04 UTC|newest]
Thread overview: 21+ 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 ` [RFC PATCH 01/14] fs/proc/vmcore: Update read_from_oldmem() for user pointer Amit Daniel Kachhap
2021-12-06 14:04 ` Christoph Hellwig [this message]
2021-12-06 14:17 ` Matthew Wilcox
2021-12-06 14:54 ` Christoph Hellwig
2021-12-06 15:07 ` Matthew Wilcox
2021-12-07 11:15 ` Christoph Hellwig
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 ` [RFC PATCH 03/14] fs/proc/vmcore: Update copy_oldmem_page() " 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 ` [RFC PATCH 05/14] x86/crash_dump_32: " Amit Daniel Kachhap
2021-12-03 10:42 ` [RFC PATCH 06/14] arm64/crash_dump: " Amit Daniel Kachhap
2021-12-03 10:42 ` [RFC PATCH 07/14] arm/crash_dump: " Amit Daniel Kachhap
2021-12-03 10:42 ` [RFC PATCH 08/14] mips/crash_dump: " Amit Daniel Kachhap
2021-12-03 10:42 ` [RFC PATCH 09/14] sh/crash_dump: " Amit Daniel Kachhap
2021-12-03 10:42 ` [RFC PATCH 10/14] riscv/crash_dump: " Amit Daniel Kachhap
2021-12-03 10:42 ` [RFC PATCH 11/14] powerpc/crash_dump: " Amit Daniel Kachhap
2021-12-03 10:42 ` [RFC PATCH 12/14] ia64/crash_dump: " Amit Daniel Kachhap
2021-12-03 10:42 ` [RFC PATCH 13/14] s390/crash_dump: " 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
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