When I tested kexec with the latest kernel, I ran into the following warning:
[ 40.712410] ------------[ cut here ]------------ [ 40.712576] WARNING: CPU: 2 PID: 1562 at kernel/kexec_core.c:1001 kimage_map_segment+0x144/0x198 [...] [ 40.816047] Call trace: [ 40.818498] kimage_map_segment+0x144/0x198 (P) [ 40.823221] ima_kexec_post_load+0x58/0xc0 [ 40.827246] __do_sys_kexec_file_load+0x29c/0x368 [...] [ 40.855423] ---[ end trace 0000000000000000 ]---
This is caused by the fact that kexec allocates the destination directly in the CMA area. In that case, the CMA kernel address should be exported directly to the IMA component, instead of using the vmalloc'd address.
Fixes: 07d24902977e ("kexec: enable CMA based contiguous allocation") Signed-off-by: Pingfan Liu piliu@redhat.com Cc: Andrew Morton akpm@linux-foundation.org Cc: Baoquan He bhe@redhat.com Cc: Alexander Graf graf@amazon.com Cc: Steven Chen chenste@linux.microsoft.com Cc: linux-integrity@vger.kernel.org Cc: stable@vger.kernel.org To: kexec@lists.infradead.org --- v1 -> v2: return page_address(page) instead of *page
kernel/kexec_core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 9a1966207041..332204204e53 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -967,6 +967,7 @@ void *kimage_map_segment(struct kimage *image, int idx) kimage_entry_t *ptr, entry; struct page **src_pages; unsigned int npages; + struct page *cma; void *vaddr = NULL; int i;
@@ -974,6 +975,9 @@ void *kimage_map_segment(struct kimage *image, int idx) size = image->segment[idx].memsz; eaddr = addr + size;
+ cma = image->segment_cma[idx]; + if (cma) + return page_address(cma); /* * Collect the source pages and map them in a contiguous VA range. */ @@ -1014,7 +1018,8 @@ void *kimage_map_segment(struct kimage *image, int idx)
void kimage_unmap_segment(void *segment_buffer) { - vunmap(segment_buffer); + if (is_vmalloc_addr(segment_buffer)) + vunmap(segment_buffer); }
struct kexec_load_limit {