On Fri, Nov 7, 2025 at 9:51 AM Baoquan He <[email protected]> wrote: > > On 11/06/25 at 06:01pm, Pingfan Liu wrote: > > On Thu, Nov 6, 2025 at 4:01 PM Baoquan He <[email protected]> wrote: > > > > > > On 11/06/25 at 02:59pm, Pingfan Liu wrote: > > > > 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. > > > > > > Well, you didn't update the log accordingly. > > > > > > > I am not sure what you mean. Do you mean the earlier content which I > > replied to you? > > No. In v1, you return cma directly. But in v2, you return its direct > mapping address, isnt' it? >
Yes. But I think it is a fault in the code, which does not convey the expression in the commit log. Do you think I should rephrase the words "the CMA kernel address" as "the CMA kernel direct mapping address"? > > > > > Do you know why cma area can't be mapped into vmalloc? > > > > > Should not the kernel direct mapping be used? > > When image->segment_cma[i] has value, image->ima_buffer_addr also > contains the physical address of the cma area, why cma physical address > can't be mapped into vmalloc and cause the failure and call trace? > It could be done using the vmalloc approach, but it's unnecessary. IIUC, kimage_map_segment() was introduced to provide a contiguous virtual address for IMA access, since the IND_SRC pages are scattered throughout the kernel. However, in the CMA case, there is already a contiguous virtual address in the kernel direct mapping range. Normally, when we have a physical address, we simply use phys_to_virt() to get its corresponding kernel virtual address. Thanks, Pingfan
