diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 13 | ||||
| -rw-r--r-- | arch/x86/include/asm/elf.h | 31 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/amd.c | 13 | ||||
| -rw-r--r-- | arch/x86/kernel/sys_x86_64.c | 81 | ||||
| -rw-r--r-- | arch/x86/mm/mmap.c | 15 | ||||
| -rw-r--r-- | arch/x86/vdso/vma.c | 9 |
6 files changed, 144 insertions, 18 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index aa47be7..af73c03 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -299,6 +299,19 @@ bytes respectively. Such letter suffixes can also be entirely omitted. behaviour to be specified. Bit 0 enables warnings, bit 1 enables fixups, and bit 2 sends a segfault. + align_va_addr= [X86-64] + Align virtual addresses by clearing slice [14:12] when + allocating a VMA at process creation time. This option + gives you up to 3% performance improvement on AMD F15h + machines (where it is enabled by default) for a + CPU-intensive style benchmark, and it can vary highly in + a microbenchmark depending on workload and compiler. + + 1: only for 32-bit processes + 2: only for 64-bit processes + on: enable for both 32- and 64-bit processes + off: disable for both 32- and 64-bit processes + amd_iommu= [HW,X86-84] Pass parameters to the AMD IOMMU driver in the system. Possible values are: diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index f2ad216..5f962df 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -4,6 +4,7 @@ /* * ELF register definitions.. */ +#include <linux/thread_info.h> #include <asm/ptrace.h> #include <asm/user.h> @@ -320,4 +321,34 @@ extern int syscall32_setup_pages(struct linux_binprm *, int exstack); extern unsigned long arch_randomize_brk(struct mm_struct *mm); #define arch_randomize_brk arch_randomize_brk +/* + * True on X86_32 or when emulating IA32 on X86_64 + */ +static inline int mmap_is_ia32(void) +{ +#ifdef CONFIG_X86_32 + return 1; +#endif +#ifdef CONFIG_IA32_EMULATION + if (test_thread_flag(TIF_IA32)) + return 1; +#endif + return 0; +} + +/* The first two values are special, do not change. See align_addr() */ +enum align_flags { + ALIGN_VA_32 = BIT(0), + ALIGN_VA_64 = BIT(1), + ALIGN_VDSO = BIT(2), + ALIGN_TOPDOWN = BIT(3), +}; + +struct va_alignment { + int flags; + unsigned long mask; +} ____cacheline_aligned; + +extern struct va_alignment va_align; +extern unsigned long align_addr(unsigned long, struct file *, enum align_flags); #endif /* _ASM_X86_ELF_H */ diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index b13ed39..b0234bc 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -458,6 +458,19 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c) "with P0 frequency!\n"); } } + + if (c->x86 == 0x15) { + unsigned long upperbit; + u32 cpuid, assoc; + + cpuid = cpuid_edx(0x80000005); + assoc = cpuid >> 16 & 0xff; + upperbit = ((cpuid >> 24) << 10) / assoc; + + va_align.mask = (upperbit - 1) & PAGE_MASK; + va_align.flags = ALIGN_VA_32 | ALIGN_VA_64; + + } } static void __cpuinit init_amd(struct cpuinfo_x86 *c) diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c index ff14a50..aaa8d09 100644 --- a/arch/x86/kernel/sys_x86_64.c +++ b/arch/x86/kernel/sys_x86_64.c @@ -18,6 +18,72 @@ #include <asm/ia32.h> #include <asm/syscalls.h> +struct __read_mostly va_alignment va_align = { + .flags = -1, +}; + +/* + * Align a virtual address to avoid aliasing in the I$ on AMD F15h. + * + * @flags denotes the allocation direction - bottomup or topdown - + * or vDSO; see call sites below. + */ +unsigned long align_addr(unsigned long addr, struct file *filp, + enum align_flags flags) +{ + unsigned long tmp_addr; + + /* handle 32- and 64-bit case with a single conditional */ + if (va_align.flags < 0 || !(va_align.flags & (2 - mmap_is_ia32()))) + return addr; + + if (!(current->flags & PF_RANDOMIZE)) + return addr; + + if (!((flags & ALIGN_VDSO) || filp)) + return addr; + + tmp_addr = addr; + + /* + * We need an address which is <= than the original + * one only when in topdown direction. + */ + if (!(flags & ALIGN_TOPDOWN)) + tmp_addr += va_align.mask; + + tmp_addr &= ~va_align.mask; + + return tmp_addr; +} + +static int __init control_va_addr_alignment(char *str) +{ + /* guard against enabling this on other CPU families */ + if (va_align.flags < 0) + return 1; + + if (*str == 0) + return 1; + + if (*str == '=') + str++; + + if (!strcmp(str, "32")) + va_align.flags = ALIGN_VA_32; + else if (!strcmp(str, "64")) + va_align.flags = ALIGN_VA_64; + else if (!strcmp(str, "off")) + va_align.flags = 0; + else if (!strcmp(str, "on")) + va_align.flags = ALIGN_VA_32 | ALIGN_VA_64; + else + return 0; + + return 1; +} +__setup("align_va_addr", control_va_addr_alignment); + SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len, unsigned long, prot, unsigned long, flags, unsigned long, fd, unsigned long, off) @@ -92,6 +158,9 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr, start_addr = addr; full_search: + + addr = align_addr(addr, filp, 0); + for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { /* At this point: (!vma || addr < vma->vm_end). */ if (end - len < addr) { @@ -117,6 +186,7 @@ full_search: mm->cached_hole_size = vma->vm_start - addr; addr = vma->vm_end; + addr = align_addr(addr, filp, 0); } } @@ -161,10 +231,13 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, /* make sure it can fit in the remaining address space */ if (addr > len) { - vma = find_vma(mm, addr-len); - if (!vma || addr <= vma->vm_start) + unsigned long tmp_addr = align_addr(addr - len, filp, + ALIGN_TOPDOWN); + + vma = find_vma(mm, tmp_addr); + if (!vma || tmp_addr + len <= vma->vm_start) /* remember the address as a hint for next time */ - return mm->free_area_cache = addr-len; + return mm->free_area_cache = tmp_addr; } if (mm->mmap_base < len) @@ -173,6 +246,8 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, addr = mm->mmap_base-len; do { + addr = align_addr(addr, filp, ALIGN_TOPDOWN); + /* * Lookup failure means no vma is above this address, * else if new region fits below vma->vm_start, diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index 1dab519..d4c0736 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -51,21 +51,6 @@ static unsigned int stack_maxrandom_size(void) #define MIN_GAP (128*1024*1024UL + stack_maxrandom_size()) #define MAX_GAP (TASK_SIZE/6*5) -/* - * True on X86_32 or when emulating IA32 on X86_64 - */ -static int mmap_is_ia32(void) -{ -#ifdef CONFIG_X86_32 - return 1; -#endif -#ifdef CONFIG_IA32_EMULATION - if (test_thread_flag(TIF_IA32)) - return 1; -#endif - return 0; -} - static int mmap_is_legacy(void) { if (current->personality & ADDR_COMPAT_LAYOUT) diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c index 7abd2be..caa42ce 100644 --- a/arch/x86/vdso/vma.c +++ b/arch/x86/vdso/vma.c @@ -69,6 +69,15 @@ static unsigned long vdso_addr(unsigned long start, unsigned len) addr = start + (offset << PAGE_SHIFT); if (addr >= end) addr = end; + + /* + * page-align it here so that get_unmapped_area doesn't + * align it wrongfully again to the next page. addr can come in 4K + * unaligned here as a result of stack start randomization. + */ + addr = PAGE_ALIGN(addr); + addr = align_addr(addr, NULL, ALIGN_VDSO); + return addr; } |
