* [RFC PATCH 13/14] s390/crash_dump: Use the new interface copy_oldmem_page_buf
[not found] <20211203104231.17597-1-amit.kachhap@arm.com>
@ 2021-12-03 10:42 ` Amit Daniel Kachhap
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From: Amit Daniel Kachhap @ 2021-12-03 10:42 UTC (permalink / raw)
To: linux-kernel
Cc: Christoph Hellwig, Vincenzo Frascino, Kevin Brodsky,
linux-fsdevel, kexec, Amit Daniel Kachhap, Heiko Carstens,
Vasily Gorbik, Christian Borntraeger, Alexander Gordeev,
linux-s390
The current interface copy_oldmem_page() passes user pointer without
__user annotation and hence does unnecessary user/kernel pointer
conversions during its implementation.
Use the interface copy_oldmem_page_buf() to avoid this issue.
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
CC: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: linux-s390 <linux-s390@vger.kernel.org>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
arch/s390/kernel/crash_dump.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
index 785d54c9350c..b1f8a908e8ca 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -214,8 +214,8 @@ static int copy_oldmem_user(void __user *dst, void *src, size_t count)
/*
* Copy one page from "oldmem"
*/
-ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
- unsigned long offset, int userbuf)
+ssize_t copy_oldmem_page_buf(unsigned long pfn, char __user *ubuf, char *kbuf,
+ size_t csize, unsigned long offset)
{
void *src;
int rc;
@@ -223,10 +223,10 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
if (!csize)
return 0;
src = (void *) (pfn << PAGE_SHIFT) + offset;
- if (userbuf)
- rc = copy_oldmem_user((void __force __user *) buf, src, csize);
+ if (ubuf)
+ rc = copy_oldmem_user((void __user *) ubuf, src, csize);
else
- rc = copy_oldmem_kernel((void *) buf, src, csize);
+ rc = copy_oldmem_kernel((void *) kbuf, src, csize);
return rc;
}
@@ -261,7 +261,7 @@ static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
* Remap "oldmem" for zfcp/nvme dump
*
* We only map available memory above HSA size. Memory below HSA size
- * is read on demand using the copy_oldmem_page() function.
+ * is read on demand using the copy_oldmem_page_buf() function.
*/
static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
unsigned long from,
--
2.17.1
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