mirror of
				https://github.com/Ysurac/openmptcprouter.git
				synced 2025-03-09 15:40:20 +00:00 
			
		
		
		
	
		
			
				
	
	
		
			74 lines
		
	
	
	
		
			2.4 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			74 lines
		
	
	
	
		
			2.4 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| From: Shiji Yang <yangshiji66@outlook.com>
 | |
| Date: Wed, 13 Mar 2024 20:28:37 +0800
 | |
| Subject: [PATCH] mips: kernel: fix detect_memory_region() function
 | |
| 
 | |
| 1. Do not use memcmp() on unallocated memory, as the new introduced
 | |
|    fortify dynamic object size check[1] will report unexpected result.
 | |
| 2. Use a fixed pattern instead of a random function pointer as the
 | |
|    magic value.
 | |
| 3. Flip magic value and double check it.
 | |
| 4. Enable this feature only for 32-bit CPUs. Currently, only ath79 and
 | |
|    ralink CPUs are using it.
 | |
| 
 | |
| [1] 439a1bcac648 ("fortify: Use __builtin_dynamic_object_size() when available")
 | |
| Signed-off-by: Shiji Yang <yangshiji66@outlook.com>
 | |
| ---
 | |
|  arch/mips/include/asm/bootinfo.h |  2 ++
 | |
|  arch/mips/kernel/setup.c         | 17 ++++++++++++-----
 | |
|  2 files changed, 14 insertions(+), 5 deletions(-)
 | |
| 
 | |
| --- a/arch/mips/include/asm/bootinfo.h
 | |
| +++ b/arch/mips/include/asm/bootinfo.h
 | |
| @@ -93,7 +93,9 @@ const char *get_system_type(void);
 | |
|  
 | |
|  extern unsigned long mips_machtype;
 | |
|  
 | |
| +#ifndef CONFIG_64BIT
 | |
|  extern void detect_memory_region(phys_addr_t start, phys_addr_t sz_min,  phys_addr_t sz_max);
 | |
| +#endif
 | |
|  
 | |
|  extern void prom_init(void);
 | |
|  extern void prom_free_prom_memory(void);
 | |
| --- a/arch/mips/kernel/setup.c
 | |
| +++ b/arch/mips/kernel/setup.c
 | |
| @@ -90,21 +90,27 @@ static struct resource bss_resource = {
 | |
|  unsigned long __kaslr_offset __ro_after_init;
 | |
|  EXPORT_SYMBOL(__kaslr_offset);
 | |
|  
 | |
| -static void *detect_magic __initdata = detect_memory_region;
 | |
| -
 | |
|  #ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
 | |
|  unsigned long ARCH_PFN_OFFSET;
 | |
|  EXPORT_SYMBOL(ARCH_PFN_OFFSET);
 | |
|  #endif
 | |
|  
 | |
| +#ifndef CONFIG_64BIT
 | |
| +static u32 detect_magic __initdata;
 | |
| +#define MIPS_MEM_TEST_PATTERN		0xaa5555aa
 | |
| +
 | |
|  void __init detect_memory_region(phys_addr_t start, phys_addr_t sz_min, phys_addr_t sz_max)
 | |
|  {
 | |
| -	void *dm = &detect_magic;
 | |
| +	void *dm = (void *)KSEG1ADDR(&detect_magic);
 | |
|  	phys_addr_t size;
 | |
|  
 | |
|  	for (size = sz_min; size < sz_max; size <<= 1) {
 | |
| -		if (!memcmp(dm, dm + size, sizeof(detect_magic)))
 | |
| -			break;
 | |
| +		__raw_writel(MIPS_MEM_TEST_PATTERN, dm);
 | |
| +		if (__raw_readl(dm) == __raw_readl(dm + size)) {
 | |
| +			__raw_writel(~MIPS_MEM_TEST_PATTERN, dm);
 | |
| +			if (__raw_readl(dm) == __raw_readl(dm + size))
 | |
| +				break;
 | |
| +		}
 | |
|  	}
 | |
|  
 | |
|  	pr_debug("Memory: %lluMB of RAM detected at 0x%llx (min: %lluMB, max: %lluMB)\n",
 | |
| @@ -115,6 +121,7 @@ void __init detect_memory_region(phys_ad
 | |
|  
 | |
|  	memblock_add(start, size);
 | |
|  }
 | |
| +#endif /* CONFIG_64BIT */
 | |
|  
 | |
|  /*
 | |
|   * Manage initrd
 |