kimage_load_cma_segment() and kimage_map_segment() both translate
a CMA segment using page_address(cma), which returns the CMA base
address. This ignores segment->mem.
On arm64, image_load() adds text_offset to segment->mem before the
segment is loaded:
kernel_segment->mem += text_offset;
kernel_segment->memsz -= text_offset;
image->start = kernel_segment->mem;
so segment->mem no longer matches the CMA base. The kernel payload is
therefore copied to the wrong offset, while image->start points past
it, and kexec jumps into the middle of the kernel.
kimage_map_segment() has the same problem for any CMA segment whose
mem has been moved.
Add kimage_cma_vaddr() to translate a boot physical address inside a
CMA segment to its virtual address, and use it in both places.
Cc: Andrew Morton <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Pasha Tatashin <[email protected]>
Cc: Pratyush Yadav <[email protected]>
Cc: Pingfan Liu <[email protected]>
Cc: Justinien Bouron <[email protected]>
Cc: Sourabh Jain <[email protected]>
Cc: Breno Leitao <[email protected]>
Cc: [email protected]
Fixes: 07d24902977e ("kexec: enable CMA based contiguous allocation")
Signed-off-by: Jinjie Ruan <[email protected]>
---
kernel/kexec_core.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index dc770b9a6d05..7f7cb77f0caa 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -738,11 +738,23 @@ static struct page *kimage_alloc_page(struct kimage
*image,
return page;
}
+/*
+ * Translate a boot physical address inside a CMA segment to a kernel
+ * virtual address. Architecture loaders may move segment->mem away from
+ * the CMA base (arm64 adds text_offset), so the offset must be preserved.
+ */
+static void *kimage_cma_vaddr(struct page *cma, unsigned long mem)
+{
+ unsigned long cma_base = page_to_boot_pfn(cma) << PAGE_SHIFT;
+
+ return page_address(cma) + (mem - cma_base);
+}
+
static int kimage_load_cma_segment(struct kimage *image, int idx)
{
struct kexec_segment *segment = &image->segment[idx];
struct page *cma = image->segment_cma[idx];
- char *ptr = page_address(cma);
+ char *ptr = kimage_cma_vaddr(cma, segment->mem);
size_t ubytes, mbytes;
int result = 0;
unsigned char __user *buf = NULL;
@@ -965,7 +977,7 @@ void *kimage_map_segment(struct kimage *image, int idx)
cma = image->segment_cma[idx];
if (cma)
- return page_address(cma);
+ return kimage_cma_vaddr(cma, image->segment[idx].mem);
addr = image->segment[idx].mem;
size = image->segment[idx].memsz;
--
2.34.1
