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: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> Cc: linux-arm-kernel <[email protected]> Signed-off-by: Amit Daniel Kachhap <[email protected]> --- arch/arm64/kernel/crash_dump.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/arch/arm64/kernel/crash_dump.c b/arch/arm64/kernel/crash_dump.c index 58303a9ec32c..ec9d5c80726c 100644 --- a/arch/arm64/kernel/crash_dump.c +++ b/arch/arm64/kernel/crash_dump.c @@ -14,20 +14,19 @@ #include <asm/memory.h> /** - * copy_oldmem_page() - copy one page from old kernel memory + * copy_oldmem_page_buf() - copy one page from old kernel memory * @pfn: page frame number to be copied - * @buf: buffer where the copied page is placed + * @ubuf: user buffer where the copied page is placed + * @kbuf: kernel buffer where the copied page is placed * @csize: number of bytes to copy * @offset: offset in bytes into the page - * @userbuf: if set, @buf is in a user address space * * This function copies one page from old kernel memory into buffer pointed by - * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes - * copied or negative error in case of failure. + * either @ubuf or @kbuf. Returns number of bytes copied or negative error in + * case of failure. */ -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; @@ -38,13 +37,13 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (!vaddr) return -ENOMEM; - if (userbuf) { - if (copy_to_user((char __user *)buf, vaddr + offset, csize)) { + if (ubuf) { + if (copy_to_user(ubuf, vaddr + offset, csize)) { memunmap(vaddr); return -EFAULT; } } else { - memcpy(buf, vaddr + offset, csize); + memcpy(kbuf, vaddr + offset, csize); } memunmap(vaddr); -- 2.17.1 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
