The exported interface copy_oldmem_page_encrypted() passes user pointer
without __user annotation and does unnecessary user/kernel pointer
conversions during the pointer propagation.
Hence it is modified to have a new parameter for user pointer. The
other similar interface copy_oldmem_page() will be updated in the
subsequent patches.
x86_64 crash dump is also modified to use this modified interface.
No functionality change intended.
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Young <dyoung@xxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Cc: x86 <x86@xxxxxxxxxx>
Cc: kexec <kexec@xxxxxxxxxxxxxxxxxxx>
Cc: linux-fsdevel <linux-fsdevel@xxxxxxxxxxxxxxx>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@xxxxxxx>
---
arch/x86/kernel/crash_dump_64.c | 12 +++++++++---
fs/proc/vmcore.c | 24 +++++++++++-------------
include/linux/crash_dump.h | 6 +++---
3 files changed, 23 insertions(+), 19 deletions(-)
diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c
index 6433513ef43a..99cd505628fa 100644
--- a/arch/x86/kernel/crash_dump_64.c
+++ b/arch/x86/kernel/crash_dump_64.c
@@ -66,10 +66,16 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
* memory with the encryption mask set to accommodate kdump on SME-enabled
* machines.
*/
-ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
- unsigned long offset, int userbuf)
+ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char __user *ubuf,
+ char *kbuf, size_t csize,
+ unsigned long offset)
{
- return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, true);
+ if (ubuf)
+ return __copy_oldmem_page(pfn, (__force char *)ubuf, csize,
+ offset, 1, true);
+ else
+ return __copy_oldmem_page(pfn, kbuf, csize,
+ offset, 0, true);
}
ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 39b4353bd37c..fa4492ef6124 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -168,16 +168,10 @@ ssize_t read_from_oldmem(char __user *ubuf, char *kbuf, size_t count,
else if (clear_user(ubuf, nr_bytes))
tmp = -EFAULT;
} else {
- if (encrypted && ubuf)
- tmp = copy_oldmem_page_encrypted(pfn,
- (__force char *)ubuf,
- nr_bytes,
- offset, 1);
- else if (encrypted && kbuf)
- tmp = copy_oldmem_page_encrypted(pfn,
- kbuf,
- nr_bytes,
- offset, 0);
+ if (encrypted)
+ tmp = copy_oldmem_page_encrypted(pfn, ubuf,
+ kbuf, nr_bytes,
+ offset);
else if (ubuf)
tmp = copy_oldmem_page(pfn, (__force char *)ubuf,
nr_bytes, offset, 1);
@@ -247,10 +241,14 @@ int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma,
* Architectures which support memory encryption override this.
*/
ssize_t __weak
-copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
- unsigned long offset, int userbuf)
+copy_oldmem_page_encrypted(unsigned long pfn, char __user *ubuf, char *kbuf,
+ size_t csize, unsigned long offset)
{
- return copy_oldmem_page(pfn, buf, csize, offset, userbuf);
+ if (ubuf)
+ return copy_oldmem_page(pfn, (__force char *)ubuf, csize,
+ offset, 1);
+ else
+ return copy_oldmem_page(pfn, kbuf, csize, offset, 0);
}
/*
diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h
index eb0ed423ccc8..36a7f08f4ad2 100644
--- a/include/linux/crash_dump.h
+++ b/include/linux/crash_dump.h
@@ -26,9 +26,9 @@ extern int remap_oldmem_pfn_range(struct vm_area_struct *vma,
extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
unsigned long, int);
-extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf,
- size_t csize, unsigned long offset,
- int userbuf);
+extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn,
+ char __user *ubuf, char *kbuf,
+ size_t csize, unsigned long offset);
void vmcore_cleanup(void);
--
2.17.1
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