From 0011036beeffeada15acd1936d67988de21ca65e Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Tue, 26 Aug 2008 22:34:57 +0900 Subject: [MIPS] Probe initrd header only if explicitly specified Currently init_initrd() probes initrd header at the last page of kernel image, but it is valid only if addinitrd was used. If addinitrd was not used, the area contains garbage so probing there might misdetect initrd header (magic number is not strictly robust). This patch introduces CONFIG_PROBE_INITRD_HEADER to explicitly enable this probing. Signed-off-by: Atsushi Nemoto Signed-off-by: Ralf Baechle --- arch/mips/Kconfig | 9 +++++++++ arch/mips/kernel/setup.c | 33 ++++++++++++++++++--------------- 2 files changed, 27 insertions(+), 15 deletions(-) diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 4da736e2533..49896a2a1d7 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -1886,6 +1886,15 @@ config STACKTRACE_SUPPORT source "init/Kconfig" +config PROBE_INITRD_HEADER + bool "Probe initrd header created by addinitrd" + depends on BLK_DEV_INITRD + help + Probe initrd header at the last page of kernel image. + Say Y here if you are using arch/mips/boot/addinitrd.c to + add initrd or initramfs image to the kernel image. + Otherwise, say N. + menu "Bus options (PCI, PCMCIA, EISA, ISA, TC)" config HW_HAS_EISA diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index 2aae76bce29..16f8edfe5cd 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -160,30 +160,33 @@ early_param("rd_size", rd_size_early); static unsigned long __init init_initrd(void) { unsigned long end; - u32 *initrd_header; /* * Board specific code or command line parser should have * already set up initrd_start and initrd_end. In these cases * perfom sanity checks and use them if all looks good. */ - if (initrd_start && initrd_end > initrd_start) - goto sanitize; + if (!initrd_start || initrd_end <= initrd_start) { +#ifdef CONFIG_PROBE_INITRD_HEADER + u32 *initrd_header; - /* - * See if initrd has been added to the kernel image by - * arch/mips/boot/addinitrd.c. In that case a header is - * prepended to initrd and is made up by 8 bytes. The fisrt - * word is a magic number and the second one is the size of - * initrd. Initrd start must be page aligned in any cases. - */ - initrd_header = __va(PAGE_ALIGN(__pa_symbol(&_end) + 8)) - 8; - if (initrd_header[0] != 0x494E5244) + /* + * See if initrd has been added to the kernel image by + * arch/mips/boot/addinitrd.c. In that case a header is + * prepended to initrd and is made up by 8 bytes. The first + * word is a magic number and the second one is the size of + * initrd. Initrd start must be page aligned in any cases. + */ + initrd_header = __va(PAGE_ALIGN(__pa_symbol(&_end) + 8)) - 8; + if (initrd_header[0] != 0x494E5244) + goto disable; + initrd_start = (unsigned long)(initrd_header + 2); + initrd_end = initrd_start + initrd_header[1]; +#else goto disable; - initrd_start = (unsigned long)(initrd_header + 2); - initrd_end = initrd_start + initrd_header[1]; +#endif + } -sanitize: if (initrd_start & ~PAGE_MASK) { pr_err("initrd start must be page aligned\n"); goto disable; -- cgit v1.2.3