hw/arm/boot: pass an address limit to and return size from load_dtb()
Add an address limit input parameter to load_dtb() so that we can tell load_dtb() how much memory the dtb is allowed to consume. If the dtb doesn't fit, return 0, otherwise return the actual size of the loaded dtb. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Message-id: 1410453915-9344-3-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
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			@ -312,7 +312,26 @@ static void set_kernel_args_old(const struct arm_boot_info *info)
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    }
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}
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static int load_dtb(hwaddr addr, const struct arm_boot_info *binfo)
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/**
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 * load_dtb() - load a device tree binary image into memory
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 * @addr:       the address to load the image at
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 * @binfo:      struct describing the boot environment
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 * @addr_limit: upper limit of the available memory area at @addr
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 *
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 * Load a device tree supplied by the machine or by the user  with the
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 * '-dtb' command line option, and put it at offset @addr in target
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 * memory.
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 *
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 * If @addr_limit contains a meaningful value (i.e., it is strictly greater
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 * than @addr), the device tree is only loaded if its size does not exceed
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 * the limit.
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 *
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 * Returns: the size of the device tree image on success,
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 *          0 if the image size exceeds the limit,
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 *          -1 on errors.
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 */
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static int load_dtb(hwaddr addr, const struct arm_boot_info *binfo,
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                    hwaddr addr_limit)
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{
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    void *fdt = NULL;
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    int size, rc;
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			@ -341,6 +360,15 @@ static int load_dtb(hwaddr addr, const struct arm_boot_info *binfo)
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        }
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    }
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    if (addr_limit > addr && size > (addr_limit - addr)) {
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        /* Installing the device tree blob at addr would exceed addr_limit.
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         * Whether this constitutes failure is up to the caller to decide,
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         * so just return 0 as size, i.e., no error.
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         */
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        g_free(fdt);
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        return 0;
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    }
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    acells = qemu_fdt_getprop_cell(fdt, "/", "#address-cells");
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    scells = qemu_fdt_getprop_cell(fdt, "/", "#size-cells");
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    if (acells == 0 || scells == 0) {
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			@ -403,7 +431,7 @@ static int load_dtb(hwaddr addr, const struct arm_boot_info *binfo)
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    g_free(fdt);
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    return 0;
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    return size;
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fail:
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    g_free(fdt);
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			@ -572,7 +600,7 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
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             */
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            hwaddr dtb_start = QEMU_ALIGN_UP(info->initrd_start + initrd_size,
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                                             4096);
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            if (load_dtb(dtb_start, info)) {
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            if (load_dtb(dtb_start, info, 0) < 0) {
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                exit(1);
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            }
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            fixupcontext[FIXUP_ARGPTR] = dtb_start;
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