kexec_file: do not add extra alignment to efi memmap
authorDave Young <dyoung@redhat.com>
Fri, 20 Apr 2018 21:56:10 +0000 (14:56 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 21 Apr 2018 00:18:36 +0000 (17:18 -0700)
Chun-Yi reported a kernel warning message below:

  WARNING: CPU: 0 PID: 0 at ../mm/early_ioremap.c:182 early_iounmap+0x4f/0x12c()
  early_iounmap(ffffffffff20018000000118) [0] size not consistent 00000120

The problem is x86 kexec_file_load adds extra alignment to the efi
memmap: in bzImage64_load():

        efi_map_sz = efi_get_runtime_map_size();
        efi_map_sz = ALIGN(efi_map_sz, 16);

And __efi_memmap_init maps with the size including the alignment bytes
but efi_memmap_unmap use nr_maps * desc_size which does not include the
extra bytes.

The alignment in kexec code is only needed for the kexec buffer internal
use Actually kexec should pass exact size of the efi memmap to 2nd
kernel.

Link: http://lkml.kernel.org/r/20180417083600.GA1972@dhcp-128-65.nay.redhat.com
Signed-off-by: Dave Young <dyoung@redhat.com>
Reported-by: joeyli <jlee@suse.com>
Tested-by: Randy Wright <rwright@hpe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/x86/kernel/kexec-bzimage64.c

index 3182908..7326078 100644 (file)
@@ -398,11 +398,10 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
         * little bit simple
         */
        efi_map_sz = efi_get_runtime_map_size();
-       efi_map_sz = ALIGN(efi_map_sz, 16);
        params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
                                MAX_ELFCOREHDR_STR_LEN;
        params_cmdline_sz = ALIGN(params_cmdline_sz, 16);
-       kbuf.bufsz = params_cmdline_sz + efi_map_sz +
+       kbuf.bufsz = params_cmdline_sz + ALIGN(efi_map_sz, 16) +
                                sizeof(struct setup_data) +
                                sizeof(struct efi_setup_data);
 
@@ -410,7 +409,7 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
        if (!params)
                return ERR_PTR(-ENOMEM);
        efi_map_offset = params_cmdline_sz;
-       efi_setup_data_offset = efi_map_offset + efi_map_sz;
+       efi_setup_data_offset = efi_map_offset + ALIGN(efi_map_sz, 16);
 
        /* Copy setup header onto bootparams. Documentation/x86/boot.txt */
        setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset;