Commit 7f00eb30 authored by Thomas Huth's avatar Thomas Huth Committed by Christian Borntraeger
Browse files

s390x/ipl: Fix crash of ELF images with arbitrary entry points 



When loading S390 kernels, the current code expects an ELF file with the
start address 0x10000. Other ELF files cause a segmentation fault. To avoid
these crashes, we should get the start address from the ELF file instead
of always using a hard-coded address.

Signed-off-by: default avatarThomas Huth <thuth@linux.vnet.ibm.com>
Acked-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 1eecf41b

hw/s390x/ipl.c

+13 −8
Original line number Diff line number Diff line
@@ -95,7 +95,8 @@ static int s390_ipl_init(SysBusDevice *dev) 
        }

        return 0;

    } else {

        kernel_size = load_elf(ipl->kernel, NULL, NULL, NULL, NULL,

        uint64_t pentry = KERN_IMAGE_START;

        kernel_size = load_elf(ipl->kernel, NULL, NULL, &pentry, NULL,

                               NULL, 1, ELF_MACHINE, 0);

        if (kernel_size == -1) {

            kernel_size = load_image_targphys(ipl->kernel, 0, ram_size);
@@ -104,15 +105,19 @@ static int s390_ipl_init(SysBusDevice *dev) 
            fprintf(stderr, "could not load kernel '%s'\n", ipl->kernel);

            return -1;

        }

        /* we have to overwrite values in the kernel image, which are "rom" */

        strcpy(rom_ptr(KERN_PARM_AREA), ipl->cmdline);



        /*

         * we can not rely on the ELF entry point, since up to 3.2 this

         * value was 0x800 (the SALIPL loader) and it wont work. For

         * all (Linux) cases 0x10000 (KERN_IMAGE_START) should be fine.

         * Is it a Linux kernel (starting at 0x10000)? If yes, we fill in the

         * kernel parameters here as well. Note: For old kernels (up to 3.2)

         * we can not rely on the ELF entry point - it was 0x800 (the SALIPL

         * loader) and it won't work. For this case we force it to 0x10000, too.

         */

        if (pentry == KERN_IMAGE_START || pentry == 0x800) {

            ipl->start_addr = KERN_IMAGE_START;

            /* Overwrite parameters in the kernel image, which are "rom" */

            strcpy(rom_ptr(KERN_PARM_AREA), ipl->cmdline);

        } else {

            ipl->start_addr = pentry;

        }

    }

    if (ipl->initrd) {

        ram_addr_t initrd_offset;