From e414889e731fe6fa4934f95f90fbc002bae6db5e Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 22 Sep 2017 11:08:55 +0100 Subject: ARM: read kernel size from zImage Signed-off-by: Russell King --- kexec/arch/arm/kexec-zImage-arm.c | 106 ++++++++++++++++++++++++++------------ 1 file changed, 74 insertions(+), 32 deletions(-) diff --git a/kexec/arch/arm/kexec-zImage-arm.c b/kexec/arch/arm/kexec-zImage-arm.c index a8c40cb..76a0b5b 100644 --- a/kexec/arch/arm/kexec-zImage-arm.c +++ b/kexec/arch/arm/kexec-zImage-arm.c @@ -355,6 +355,34 @@ static int setup_dtb_prop(char **bufp, off_t *sizep, int parentoffset, return 0; } +static const struct zimage_tag *find_extension_tag(const char *buf, off_t len, + uint32_t tag_id) +{ + const struct zimage_header *hdr = (const struct zimage_header *)buf; + const struct zimage_tag *tag; + uint32_t offset, size; + uint32_t max = len - sizeof(struct tag_header); + + if (len < sizeof(*hdr) || + hdr->magic != ZIMAGE_MAGIC || + hdr->magic2 != ZIMAGE_MAGIC2) + return NULL; + + for (offset = hdr->extension_tag_offset; + (tag = (void *)(buf + offset)) != NULL && + offset < max && + (size = le32_to_cpu(byte_size(tag))) != 0 && + offset + size < len; + offset += size) { + dbgprintf(" offset 0x%08x tag 0x%08x size %u\n", + offset, le32_to_cpu(tag->hdr.tag), size); + if (tag->hdr.tag == tag_id) + return tag; + } + + return NULL; +} + int zImage_arm_load(int argc, char **argv, const char *buf, off_t len, struct kexec_info *info) { @@ -362,6 +390,7 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len, unsigned long base, kernel_base; unsigned int atag_offset = 0x1000; /* 4k offset from memory start */ unsigned int extra_size = 0x8000; /* TEXT_OFFSET */ + const struct zimage_tag *tag; size_t kernel_mem_size; const char *command_line; char *modified_cmdline = NULL; @@ -480,35 +509,6 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len, if (size < len) len = size; } - - /* Do we have an extension table? */ - if (hdr->magic2 == ZIMAGE_MAGIC2 && !kexec_arm_image_size) { - uint32_t offset = hdr->extension_tag_offset; - uint32_t max = len - sizeof(struct tag_header); - struct zimage_tag *tag; - - dbgprintf("zImage has tags\n"); - - for (offset = hdr->extension_tag_offset; - (tag = (void *)(buf + offset)) != NULL && - offset < max && byte_size(tag) && - offset + byte_size(tag) < len; - offset += byte_size(tag)) { - dbgprintf(" offset 0x%08x tag 0x%08x size %u\n", - offset, tag->hdr.tag, byte_size(tag)); - if (tag->hdr.tag == ZIMAGE_TAG_KRNL_SIZE) { - uint32_t *p = (void *)buf + - tag->u.krnl_size.size_ptr; - - kexec_arm_image_size = - get_unaligned(p) + - tag->u.krnl_size.bss_size; - } - } - - dbgprintf("kernel image size: 0x%08x\n", - kexec_arm_image_size); - } } /* Handle android images, 2048 is the minimum page size */ @@ -553,9 +553,40 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len, kernel_mem_size = len + 4; /* - * If the user didn't specify the size of the image, assume the - * maximum kernel compression ratio is 4. Note that we must - * include space for the compressed image here as well. + * Check for a kernel size extension, and set or validate the + * image size. This is the total space needed to avoid the + * boot kernel BSS, so other data (such as initrd) does not get + * overwritten. + */ + tag = find_extension_tag(buf, len, ZIMAGE_TAG_KRNL_SIZE); + if (tag) { + uint32_t *p = (void *)buf + le32_to_cpu(tag->u.krnl_size.size_ptr); + uint32_t edata_size = le32_to_cpu(get_unaligned(p)); + uint32_t bss_size = le32_to_cpu(tag->u.krnl_size.bss_size); + uint32_t kernel_size = edata_size + bss_size; + + /* + * While decompressing, the zImage is placed past _edata + * of the decompressed kernel. Ensure we account for that. + */ + if (kernel_size < edata_size + len) + kernel_size = edata_size + len; + + if (kexec_arm_image_size == 0) + kexec_arm_image_size = kernel_size; + else if (kexec_arm_image_size < kernel_size) { + fprintf(stderr, + "Kernel size is too small, increasing to 0x%lx\n", + (unsigned long)kernel_size); + kexec_arm_image_size = kernel_size; + } + } + + /* + * If the user didn't specify the size of the image, and we don't + * have the extension tables, assume the maximum kernel compression + * ratio is 4. Note that we must include space for the compressed + * image here as well. */ if (!kexec_arm_image_size) kexec_arm_image_size = len * 5; @@ -617,6 +648,10 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len, */ initrd_base = kernel_base + _ALIGN(kexec_arm_image_size, page_size); + dbgprintf("%-6s: address=0x%08lx size=0x%08lx\n", "Kernel", + (unsigned long)kernel_base, + (unsigned long)kexec_arm_image_size); + if (ramdisk_buf) { /* * Find a hole to place the initrd. The crash kernel use @@ -630,6 +665,10 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len, return -1; } + dbgprintf("%-6s: address=0x%08lx size=0x%08lx\n", "Initrd", + (unsigned long)initrd_base, + (unsigned long)initrd_size); + add_segment(info, ramdisk_buf, initrd_size, initrd_base, initrd_size); } @@ -708,6 +747,9 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len, return -1; } + dbgprintf("%-6s: address=0x%08lx size=0x%08lx\n", "DT", + (unsigned long)dtb_offset, (unsigned long)dtb_length); + add_segment(info, dtb_buf, dtb_length, dtb_offset, dtb_length); } -- cgit