The exported interface copy_oldmem_page 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. However instead of updating it directly a new interface copy_oldmem_page_buf() is added as copy_oldmem_page() is used across different archs. This old interface copy_oldmem_page() will be deleted after all the archs are modified to use the new interface. The weak implementation of both copy_oldmem_page() and copy_oldmem_page_buf() are added temporarily to keep the kernel building for the subsequent patches. As a consequence, crash dump is temporarily broken for the archs till the patch where it implements its own copy_oldmem_page_buf(). Cc: Dave Young <[email protected]> Cc: Baoquan He <[email protected]> Cc: Vivek Goyal <[email protected]> Cc: kexec <[email protected]> Cc: linux-fsdevel <[email protected]> Signed-off-by: Amit Daniel Kachhap <[email protected]> --- fs/proc/vmcore.c | 27 +++++++++++++++++---------- include/linux/crash_dump.h | 3 +++ 2 files changed, 20 insertions(+), 10 deletions(-) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index fa4492ef6124..d01b85c043dd 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -172,12 +172,9 @@ ssize_t read_from_oldmem(char __user *ubuf, char *kbuf, size_t count, 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); else - tmp = copy_oldmem_page(pfn, kbuf, nr_bytes, - offset, 0); + tmp = copy_oldmem_page_buf(pfn, ubuf, kbuf, + nr_bytes, offset); } if (tmp < 0) { up_read(&vmcore_cb_rwsem); @@ -244,11 +241,21 @@ ssize_t __weak copy_oldmem_page_encrypted(unsigned long pfn, char __user *ubuf, char *kbuf, size_t csize, unsigned long offset) { - if (ubuf) - return copy_oldmem_page(pfn, (__force char *)ubuf, csize, - offset, 1); - else - return copy_oldmem_page(pfn, kbuf, csize, offset, 0); + return copy_oldmem_page_buf(pfn, ubuf, kbuf, csize, offset); +} + +ssize_t __weak +copy_oldmem_page_buf(unsigned long pfn, char __user *ubuf, char *kbuf, + size_t csize, unsigned long offset) +{ + return -EOPNOTSUPP; +} + +ssize_t __weak +copy_oldmem_page(unsigned long pfn, char *ubuf, size_t csize, + unsigned long offset, int userbuf) +{ + return -EOPNOTSUPP; } /* diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h index 36a7f08f4ad2..725c4e053ecf 100644 --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -26,6 +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_buf(unsigned long pfn, char __user *ubuf, + char *kbuf, size_t csize, + unsigned long offset); extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char __user *ubuf, char *kbuf, size_t csize, unsigned long offset); -- 2.17.1 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
