From 761cdf6aacdb76f819050f4938cdab1f4cdcb945 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 14 Jul 2008 09:58:55 +0200 Subject: [S390] initrd vs bss section clearing. In case the initrd is located within the bss section it will be overwritten when the section is cleared. To prevent this just move the initrd right behind the bss section if it starts within the section. The current code already moves the initrd if the bootmem allocator bitmap would overwrite it. With this patch we should be safe against initrd corruptions. Cc: Peter Oberparleiter Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/early.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'arch/s390/kernel') diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c index d0e09684b9c..b2226e41f06 100644 --- a/arch/s390/kernel/early.c +++ b/arch/s390/kernel/early.c @@ -380,6 +380,23 @@ static __init void detect_machine_facilities(void) #endif } +static __init void rescue_initrd(void) +{ +#ifdef CONFIG_BLK_DEV_INITRD + /* + * Move the initrd right behind the bss section in case it starts + * within the bss section. So we don't overwrite it when the bss + * section gets cleared. + */ + if (!INITRD_START || !INITRD_SIZE) + return; + if (INITRD_START >= (unsigned long) __bss_stop) + return; + memmove(__bss_stop, (void *) INITRD_START, INITRD_SIZE); + INITRD_START = (unsigned long) __bss_stop; +#endif +} + /* * Save ipl parameters, clear bss memory, initialize storage keys * and create a kernel NSS at startup if the SAVESYS= parm is defined @@ -389,6 +406,7 @@ void __init startup_init(void) unsigned long long memsize; ipl_save_parameters(); + rescue_initrd(); clear_bss_section(); init_kernel_storage_key(); lockdep_init(); -- cgit v1.2.3-70-g09d2