The whole kernel text/data/bss must be reserved to prevent sudden kernel crashes, for instance, due to unexpected non-zero default static variables initializations.
Signed-off-by: Serge Semin <[email protected]> --- arch/mips/kernel/setup.c | 117 +++++++++++++++-------------- 1 file changed, 59 insertions(+), 58 deletions(-) diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index 9c1a60d..e746793 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -472,6 +472,62 @@ static void __init mips_reserve_initrd_mem(void) { } #endif /* + * Reserve kernel code and data within memblock allocator + */ +static void __init mips_reserve_kernel_mem(void) +{ + phys_addr_t start, size; + + /* + * Add kernel _text, _data, _bss, __init*, upto __end sections to + * boot_mem_map and memblock. We must reserve all of them! + */ + start = __pa_symbol(&_text); + size = __pa_symbol(&_end) - start; + add_memory_region(start, size, BOOT_MEM_RAM); + /* + * It needs to be reserved within memblock as well. It's ok if memory + * has already been reserved with previous method + */ + memblock_reserve(start, size); + + /* Reserve nosave region for hibernation */ + start = __pa_symbol(&__nosave_begin); + size = __pa_symbol(&__nosave_end) - start; + add_memory_region(start, size, BOOT_MEM_RAM); + memblock_reserve(start, size); + + /* Initialize some init_mm fieldis. We may not need this? */ + init_mm.start_code = (unsigned long)&_text; + init_mm.end_code = (unsigned long)&_etext; + init_mm.end_data = (unsigned long)&_edata; + init_mm.brk = (unsigned long)&_end; + + /* + * The kernel reserves all memory below its _end symbol as bootmem, + * but the kernel may now be at a much higher address. The memory + * between the original and new locations may be returned to the system. + */ +#ifdef CONFIG_RELOCATABLE + if (__pa_symbol(&_text) > __pa_symbol(VMLINUX_LOAD_ADDRESS)) { + phys_addr_t offset; + extern void show_kernel_relocation(const char *level); + + offset = __pa_symbol(_text) - __pa_symbol(VMLINUX_LOAD_ADDRESS); + memblock_free(__pa_symbol(VMLINUX_LOAD_ADDRESS), offset); + +#if defined(CONFIG_DEBUG_KERNEL) && defined(CONFIG_DEBUG_INFO) + /* + * This information is necessary when debugging the kernel + * But is a security vulnerability otherwise! + */ + show_kernel_relocation(KERN_INFO); +#endif + } +#endif +} + +/* * Reserve memory occupied by elfcorehdr */ static void __init mips_reserve_elfcorehdr(void) @@ -590,6 +646,9 @@ static void __init bootmem_init(void) unsigned long bootmap_size; int i; + /* Reserve kernel code/data memory */ + mips_reserve_kernel_mem(); + /* Check and reserve memory occupied by initrd */ mips_reserve_initrd_mem(); @@ -766,29 +825,6 @@ static void __init bootmem_init(void) * Reserve the bootmap memory. */ reserve_bootmem(PFN_PHYS(mapstart), bootmap_size, BOOTMEM_DEFAULT); - -#ifdef CONFIG_RELOCATABLE - /* - * The kernel reserves all memory below its _end symbol as bootmem, - * but the kernel may now be at a much higher address. The memory - * between the original and new locations may be returned to the system. - */ - if (__pa_symbol(_text) > __pa_symbol(VMLINUX_LOAD_ADDRESS)) { - unsigned long offset; - extern void show_kernel_relocation(const char *level); - - offset = __pa_symbol(_text) - __pa_symbol(VMLINUX_LOAD_ADDRESS); - free_bootmem(__pa_symbol(VMLINUX_LOAD_ADDRESS), offset); - -#if defined(CONFIG_DEBUG_KERNEL) && defined(CONFIG_DEBUG_INFO) - /* - * This information is necessary when debugging the kernel - * But is a security vulnerability otherwise! - */ - show_kernel_relocation(KERN_INFO); -#endif - } -#endif } #endif /* CONFIG_SGI_IP27 */ @@ -816,25 +852,6 @@ static void __init bootmem_init(void) * initialization hook for anything else was introduced. */ -static void __init arch_mem_addpart(phys_addr_t mem, phys_addr_t end, int type) -{ - phys_addr_t size; - int i; - - size = end - mem; - if (!size) - return; - - /* Make sure it is in the boot_mem_map */ - for (i = 0; i < boot_mem_map.nr_map; i++) { - if (mem >= boot_mem_map.map[i].addr && - mem < (boot_mem_map.map[i].addr + - boot_mem_map.map[i].size)) - return; - } - add_memory_region(mem, size, type); -} - static void __init arch_mem_init(char **cmdline_p) { struct memblock_region *reg; @@ -846,19 +863,6 @@ static void __init arch_mem_init(char **cmdline_p) /* Parse passed parameters */ mips_parse_param(cmdline_p); - /* - * Make sure all kernel memory is in the maps. The "UP" and - * "DOWN" are opposite for initdata since if it crosses over - * into another memory section you don't want that to be - * freed when the initdata is freed. - */ - arch_mem_addpart(PFN_DOWN(__pa_symbol(&_text)) << PAGE_SHIFT, - PFN_UP(__pa_symbol(&_edata)) << PAGE_SHIFT, - BOOT_MEM_RAM); - arch_mem_addpart(PFN_UP(__pa_symbol(&__init_begin)) << PAGE_SHIFT, - PFN_DOWN(__pa_symbol(&__init_end)) << PAGE_SHIFT, - BOOT_MEM_INIT_RAM); - pr_info("Determined physical RAM map:\n"); print_memory_map(); @@ -873,9 +877,6 @@ static void __init arch_mem_init(char **cmdline_p) for_each_memblock(reserved, reg) if (reg->size != 0) reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT); - - reserve_bootmem_region(__pa_symbol(&__nosave_begin), - __pa_symbol(&__nosave_end)); /* Reserve for hibernation */ } static void __init resource_init(void) -- 2.6.6
