diff options
Diffstat (limited to 'target/linux/generic/pending-6.1/350-mips-kernel-fix-detect_memory_region-function.patch')
-rw-r--r-- | target/linux/generic/pending-6.1/350-mips-kernel-fix-detect_memory_region-function.patch | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/target/linux/generic/pending-6.1/350-mips-kernel-fix-detect_memory_region-function.patch b/target/linux/generic/pending-6.1/350-mips-kernel-fix-detect_memory_region-function.patch new file mode 100644 index 0000000000..3bf7ae98bf --- /dev/null +++ b/target/linux/generic/pending-6.1/350-mips-kernel-fix-detect_memory_region-function.patch @@ -0,0 +1,74 @@ +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 |