In the following patch they will be used to compute: - mmap_base in compat sys_mmap() in native 64-bit binary and vice-versa - mmap_base for native sys_mmap() in compat x32/ia32-bit binary.
Signed-off-by: Dmitry Safonov <[email protected]> --- arch/x86/include/asm/elf.h | 9 +++++++-- arch/x86/include/asm/processor.h | 2 +- arch/x86/mm/hugetlbpage.c | 2 +- arch/x86/mm/mmap.c | 31 +++++++++++++++++++------------ 4 files changed, 28 insertions(+), 16 deletions(-) diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index ee1a87782b2c..9655a8390da4 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -286,6 +286,7 @@ do { \ #ifdef CONFIG_X86_32 +#define STACK_RND_MASK_MODE(native) (0x7ff) #define STACK_RND_MASK (0x7ff) #define ARCH_DLINFO ARCH_DLINFO_IA32 @@ -295,7 +296,8 @@ do { \ #else /* CONFIG_X86_32 */ /* 1GB for 64bit, 8MB for 32bit */ -#define STACK_RND_MASK (test_thread_flag(TIF_ADDR32) ? 0x7ff : 0x3fffff) +#define STACK_RND_MASK_MODE(native) ((native) ? 0x3fffff : 0x7ff) +#define STACK_RND_MASK STACK_RND_MASK_MODE(!test_thread_flag(TIF_ADDR32)) #define ARCH_DLINFO \ do { \ @@ -320,7 +322,7 @@ if (test_thread_flag(TIF_X32)) \ else \ ARCH_DLINFO_IA32 -#define COMPAT_ELF_ET_DYN_BASE (TASK_UNMAPPED_BASE + 0x1000000) +#define COMPAT_ELF_ET_DYN_BASE (TASK_UNMAPPED_BASE(TASK_SIZE) + 0x1000000) #endif /* !CONFIG_X86_32 */ @@ -353,6 +355,9 @@ static inline int mmap_is_ia32(void) extern unsigned long arch_compat_rnd(void); #endif extern unsigned long arch_native_rnd(void); +extern unsigned long mmap_base(unsigned long rnd, unsigned long task_size); +extern unsigned long mmap_legacy_base(unsigned long rnd, + unsigned long task_size); /* Do not change the values. See get_align_mask() */ enum align_flags { diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index eaf100508c36..2bf5787fac37 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -844,7 +844,7 @@ extern void start_thread(struct pt_regs *regs, unsigned long new_ip, * This decides where the kernel will search for a free chunk of vm * space during mmap's. */ -#define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 3)) +#define TASK_UNMAPPED_BASE(task_size) (PAGE_ALIGN(task_size / 3)) #define KSTK_EIP(task) (task_pt_regs(task)->ip) diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c index 2ae8584b44c7..62dfa3fa3ee0 100644 --- a/arch/x86/mm/hugetlbpage.c +++ b/arch/x86/mm/hugetlbpage.c @@ -113,7 +113,7 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file, if (addr & ~PAGE_MASK) { VM_BUG_ON(addr != -ENOMEM); info.flags = 0; - info.low_limit = TASK_UNMAPPED_BASE; + info.low_limit = TASK_UNMAPPED_BASE(TASK_SIZE); info.high_limit = TASK_SIZE; addr = vm_unmapped_area(&info); } diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index 0b2007b08194..b64362270165 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -35,12 +35,14 @@ struct va_alignment __read_mostly va_align = { .flags = -1, }; -static unsigned long stack_maxrandom_size(void) +static unsigned long stack_maxrandom_size(unsigned long task_size) { unsigned long max = 0; if ((current->flags & PF_RANDOMIZE) && !(current->personality & ADDR_NO_RANDOMIZE)) { - max = ((-1UL) & STACK_RND_MASK) << PAGE_SHIFT; + max = (-1UL); + max &= STACK_RND_MASK_MODE(task_size == TASK_SIZE_MAX); + max <<= PAGE_SHIFT; } return max; @@ -51,8 +53,8 @@ static unsigned long stack_maxrandom_size(void) * * Leave an at least ~128 MB hole with possible stack randomization. */ -#define MIN_GAP (128*1024*1024UL + stack_maxrandom_size()) -#define MAX_GAP (TASK_SIZE/6*5) +#define MIN_GAP(task_size) (128*1024*1024UL + stack_maxrandom_size(task_size)) +#define MAX_GAP(task_size) (task_size/6*5) static int mmap_is_legacy(void) { @@ -88,16 +90,21 @@ unsigned long arch_mmap_rnd(void) return arch_native_rnd(); } -static unsigned long mmap_base(unsigned long rnd) +unsigned long mmap_base(unsigned long rnd, unsigned long task_size) { unsigned long gap = rlimit(RLIMIT_STACK); - if (gap < MIN_GAP) - gap = MIN_GAP; - else if (gap > MAX_GAP) - gap = MAX_GAP; + if (gap < MIN_GAP(task_size)) + gap = MIN_GAP(task_size); + else if (gap > MAX_GAP(task_size)) + gap = MAX_GAP(task_size); - return PAGE_ALIGN(TASK_SIZE - gap - rnd); + return PAGE_ALIGN(task_size - gap - rnd); +} + +unsigned long mmap_legacy_base(unsigned long rnd, unsigned long task_size) +{ + return TASK_UNMAPPED_BASE(task_size) + rnd; } /* @@ -111,13 +118,13 @@ void arch_pick_mmap_layout(struct mm_struct *mm) if (current->flags & PF_RANDOMIZE) random_factor = arch_mmap_rnd(); - mm->mmap_legacy_base = TASK_UNMAPPED_BASE + random_factor; + mm->mmap_legacy_base = mmap_legacy_base(random_factor, TASK_SIZE); if (mmap_is_legacy()) { mm->mmap_base = mm->mmap_legacy_base; mm->get_unmapped_area = arch_get_unmapped_area; } else { - mm->mmap_base = mmap_base(random_factor); + mm->mmap_base = mmap_base(random_factor, TASK_SIZE); mm->get_unmapped_area = arch_get_unmapped_area_topdown; } } -- 2.11.0
