From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: David Hildenbrand <david@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
"Michael S. Tsirkin" <mst@redhat.com>,
Jason Wang <jasowang@redhat.com>,
Alexey Dobriyan <adobriyan@gmail.com>,
Mike Rapoport <rppt@kernel.org>,
"Matthew Wilcox (Oracle)" <willy@infradead.org>,
Oscar Salvador <osalvador@suse.de>,
Michal Hocko <mhocko@suse.com>, Roman Gushchin <guro@fb.com>,
Alex Shi <alex.shi@linux.alibaba.com>,
Steven Price <steven.price@arm.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Aili Yao <yaoaili@kingsoft.com>, Jiri Bohac <jbohac@suse.cz>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Wei Liu <wei.liu@kernel.org>,
Naoya Horiguchi <naoya.horiguchi@nec.com>,
linux-hyperv@vger.kernel.org,
virtualization@lists.linux-foundation.org,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
Mike Rapoport <rppt@linux.ibm.com>
Subject: [PATCH v2 2/6] fs/proc/kcore: pfn_is_ram check only applies to KCORE_RAM
Date: Fri, 14 May 2021 19:22:43 +0200 [thread overview]
Message-ID: <20210514172247.176750-3-david@redhat.com> (raw)
In-Reply-To: <20210514172247.176750-1-david@redhat.com>
Let's resturcture the code, using switch-case, and checking pfn_is_ram()
only when we are dealing with KCORE_RAM.
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
fs/proc/kcore.c | 35 +++++++++++++++++++++++++++--------
1 file changed, 27 insertions(+), 8 deletions(-)
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index 09f77d3c6e15..ed6fbb3bd50c 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -483,25 +483,36 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
goto out;
}
m = NULL; /* skip the list anchor */
- } else if (!pfn_is_ram(__pa(start) >> PAGE_SHIFT)) {
- if (clear_user(buffer, tsz)) {
- ret = -EFAULT;
- goto out;
- }
- } else if (m->type == KCORE_VMALLOC) {
+ goto skip;
+ }
+
+ switch (m->type) {
+ case KCORE_VMALLOC:
vread(buf, (char *)start, tsz);
/* we have to zero-fill user buffer even if no read */
if (copy_to_user(buffer, buf, tsz)) {
ret = -EFAULT;
goto out;
}
- } else if (m->type == KCORE_USER) {
+ break;
+ case KCORE_USER:
/* User page is handled prior to normal kernel page: */
if (copy_to_user(buffer, (char *)start, tsz)) {
ret = -EFAULT;
goto out;
}
- } else {
+ break;
+ case KCORE_RAM:
+ if (!pfn_is_ram(__pa(start) >> PAGE_SHIFT)) {
+ if (clear_user(buffer, tsz)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ break;
+ }
+ fallthrough;
+ case KCORE_VMEMMAP:
+ case KCORE_TEXT:
if (kern_addr_valid(start)) {
/*
* Using bounce buffer to bypass the
@@ -525,7 +536,15 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
goto out;
}
}
+ break;
+ default:
+ pr_warn_once("Unhandled KCORE type: %d\n", m->type);
+ if (clear_user(buffer, tsz)) {
+ ret = -EFAULT;
+ goto out;
+ }
}
+skip:
buflen -= tsz;
*fpos += tsz;
buffer += tsz;
--
2.31.1
next prev parent reply other threads:[~2021-05-14 17:23 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-14 17:22 [PATCH v2 0/6] fs/proc/kcore: don't read offline sections, logically offline pages and hwpoisoned pages David Hildenbrand
2021-05-14 17:22 ` [PATCH v2 1/6] fs/proc/kcore: drop KCORE_REMAP and KCORE_OTHER David Hildenbrand
2021-05-14 17:22 ` David Hildenbrand [this message]
2021-05-14 17:22 ` [PATCH v2 3/6] fs/proc/kcore: don't read offline sections, logically offline pages and hwpoisoned pages David Hildenbrand
2021-05-25 8:09 ` Oscar Salvador
2021-05-14 17:22 ` [PATCH v2 4/6] mm: introduce page_offline_(begin|end|freeze|thaw) to synchronize setting PageOffline() David Hildenbrand
2021-05-17 6:43 ` Mike Rapoport
2021-05-17 15:18 ` David Hildenbrand
2021-05-25 8:16 ` Oscar Salvador
2021-05-14 17:22 ` [PATCH v2 5/6] virtio-mem: use page_offline_(start|end) when " David Hildenbrand
2021-05-17 6:43 ` Mike Rapoport
2021-05-25 8:20 ` Oscar Salvador
2021-05-14 17:22 ` [PATCH v2 6/6] fs/proc/kcore: use page_offline_(freeze|thaw) David Hildenbrand
2021-05-17 6:44 ` Mike Rapoport
2021-05-25 8:21 ` Oscar Salvador
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