The current interface copy_oldmem_page() passes user pointer without __user annotation and hence does unnecessary user/kernel pointer conversions during its implementation.
Implement the interface copy_oldmem_page_buf() to avoid this issue. Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Dave Hansen <[email protected]> Cc: x86 <[email protected]> Signed-off-by: Amit Daniel Kachhap <[email protected]> --- arch/x86/kernel/crash_dump_32.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/arch/x86/kernel/crash_dump_32.c b/arch/x86/kernel/crash_dump_32.c index 5fcac46aaf6b..9932cd62ded1 100644 --- a/arch/x86/kernel/crash_dump_32.c +++ b/arch/x86/kernel/crash_dump_32.c @@ -30,20 +30,20 @@ static inline bool is_crashed_pfn_valid(unsigned long pfn) } /** - * copy_oldmem_page - copy one page from "oldmem" + * copy_oldmem_page_buf - copy one page from "oldmem" * @pfn: page frame number to be copied - * @buf: target memory address for the copy; this can be in kernel address - * space or user address space (see @userbuf) + * @ubuf: target user memory pointer for the copy; use copy_to_user() if this + * pointer is not NULL + * @kbuf: target kernel memory pointer for the copy; use memcpy() if this + * pointer is not NULL * @csize: number of bytes to copy * @offset: offset in bytes into the page (based on pfn) to begin the copy - * @userbuf: if set, @buf is in user address space, use copy_to_user(), - * otherwise @buf is in kernel address space, use memcpy(). * - * Copy a page from "oldmem". For this page, there might be no pte mapped - * in the current kernel. + * Copy a page from "oldmem" into the buffer pointed by either @ubuf or @kbuf. + * For this page, there might be no pte mapped in the current kernel. */ -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 *vaddr; @@ -55,10 +55,10 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, vaddr = kmap_local_pfn(pfn); - if (!userbuf) { - memcpy(buf, vaddr + offset, csize); + if (!ubuf) { + memcpy(kbuf, vaddr + offset, csize); } else { - if (copy_to_user(buf, vaddr + offset, csize)) + if (copy_to_user(ubuf, vaddr + offset, csize)) csize = -EFAULT; } -- 2.17.1 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
