Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261163AbVA0U2b (ORCPT ); Thu, 27 Jan 2005 15:28:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261172AbVA0U2b (ORCPT ); Thu, 27 Jan 2005 15:28:31 -0500 Received: from phoenix.infradead.org ([81.187.226.98]:55556 "EHLO phoenix.infradead.org") by vger.kernel.org with ESMTP id S261163AbVA0U1Z (ORCPT ); Thu, 27 Jan 2005 15:27:25 -0500 Date: Thu, 27 Jan 2005 20:27:21 +0000 From: Arjan van de Ven To: Christoph Hellwig , linux-kernel@vger.kernel.org, akpm@osdl.org, torvalds@osdl.org Subject: Re: Patch 4/6 randomize the stack pointer Message-ID: <20050127202720.GA12390@infradead.org> References: <20050127101117.GA9760@infradead.org> <20050127101322.GE9760@infradead.org> <20050127202335.GA2033@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050127202335.GA2033@infradead.org> User-Agent: Mutt/1.4.1i X-SRS-Rewrite: SMTP reverse-path rewritten from by phoenix.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 12263 Lines: 336 On Thu, Jan 27, 2005 at 08:23:35PM +0000, Christoph Hellwig wrote: > > + p = arch_align_stack((unsigned long)p); > > looking at the code p already is unsigned long, so the cast is not needed. yeah how about this one instead ? The patch below replaces the existing 8Kb randomisation of the userspace stack pointer (which is currently only done for Hyperthreaded P-IVs) with a more general randomisation over a 64Kb range. 64Kb is not a lot, but it's a start and once the dust settles we can increase this value to a more agressive value. Signed-off-by Arjan van de Ven diff -purN step1/arch/i386/kernel/process.c step2/arch/i386/kernel/process.c --- step1/arch/i386/kernel/process.c 2005-01-26 18:24:35.000000000 +0100 +++ step2/arch/i386/kernel/process.c 2005-01-27 21:10:19.000000000 +0100 @@ -36,6 +36,7 @@ #include #include #include +#include #include #include @@ -828,3 +829,9 @@ asmlinkage int sys_get_thread_area(struc return 0; } +unsigned long arch_align_stack(unsigned long sp) +{ + if (randomize_va_space) + sp -= ((get_random_int() % 4096) << 4); + return sp & ~0xf; +} diff -purN step1/arch/x86_64/kernel/process.c step2/arch/x86_64/kernel/process.c --- step1/arch/x86_64/kernel/process.c 2005-01-26 18:24:49.000000000 +0100 +++ step2/arch/x86_64/kernel/process.c 2005-01-27 21:10:19.000000000 +0100 @@ -743,3 +743,10 @@ int dump_task_regs(struct task_struct *t return 1; } + +unsigned long arch_align_stack(unsigned long sp) +{ + if (randomize_vs_space) + sp -= ((get_random_int() % 4096) << 4); + return sp & ~0xf; +} diff -purN step1/fs/binfmt_elf.c step2/fs/binfmt_elf.c --- step1/fs/binfmt_elf.c 2005-01-27 21:09:32.000000000 +0100 +++ step2/fs/binfmt_elf.c 2005-01-27 21:18:58.000000000 +0100 @@ -165,21 +165,14 @@ create_elf_tables(struct linux_binprm *b if (k_platform) { size_t len = strlen(k_platform) + 1; -#ifdef CONFIG_X86_HT /* * In some cases (e.g. Hyper-Threading), we want to avoid L1 * evictions by the processes running on the same package. One * thing we can do is to shuffle the initial stack for them. - * - * The conditionals here are unneeded, but kept in to make the - * code behaviour the same as pre change unless we have - * hyperthreaded processors. This should be cleaned up - * before 2.6 */ - if (smp_num_siblings > 1) - STACK_ALLOC(p, ((current->pid % 64) << 7)); -#endif + p = arch_align_stack(p); + u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); if (__copy_to_user(u_platform, k_platform, len)) return -EFAULT; diff -purN step1/fs/exec.c step2/fs/exec.c --- step1/fs/exec.c 2005-01-27 21:09:32.000000000 +0100 +++ step2/fs/exec.c 2005-01-27 21:18:37.000000000 +0100 @@ -400,7 +400,8 @@ int setup_arg_pages(struct linux_binprm while (i < MAX_ARG_PAGES) bprm->page[i++] = NULL; #else - stack_base = stack_top - MAX_ARG_PAGES * PAGE_SIZE; + stack_base = arch_align_stack(STACK_TOP - MAX_ARG_PAGES*PAGE_SIZE); + stack_base = PAGE_ALIGN(stack_base); bprm->p += stack_base; mm->arg_start = bprm->p; arg_size = stack_top - (PAGE_MASK & (unsigned long) mm->arg_start); diff -purN step1/include/asm-alpha/system.h step2/include/asm-alpha/system.h --- step1/include/asm-alpha/system.h 2004-12-24 22:34:58.000000000 +0100 +++ step2/include/asm-alpha/system.h 2005-01-27 21:16:20.000000000 +0100 @@ -621,4 +621,6 @@ __cmpxchg(volatile void *ptr, unsigned l #endif /* __ASSEMBLY__ */ +#define arch_align_stack(x) (x) + #endif diff -purN step1/include/asm-arm/system.h step2/include/asm-arm/system.h --- step1/include/asm-arm/system.h 2004-12-24 22:34:00.000000000 +0100 +++ step2/include/asm-arm/system.h 2005-01-27 21:16:37.000000000 +0100 @@ -383,6 +383,8 @@ static inline unsigned long __xchg(unsig #endif /* __ASSEMBLY__ */ +#define arch_align_stack(x) (x) + #endif /* __KERNEL__ */ #endif diff -purN step1/include/asm-arm26/system.h step2/include/asm-arm26/system.h --- step1/include/asm-arm26/system.h 2005-01-26 18:24:39.000000000 +0100 +++ step2/include/asm-arm26/system.h 2005-01-27 21:16:33.000000000 +0100 @@ -245,6 +245,8 @@ static inline unsigned long __xchg(unsig #endif /* __ASSEMBLY__ */ +#define arch_align_stack(x) (x) + #endif /* __KERNEL__ */ #endif diff -purN step1/include/asm-cris/system.h step2/include/asm-cris/system.h --- step1/include/asm-cris/system.h 2004-12-24 22:34:58.000000000 +0100 +++ step2/include/asm-cris/system.h 2005-01-27 21:16:41.000000000 +0100 @@ -69,4 +69,6 @@ extern inline unsigned long __xchg(unsig return x; } +#define arch_align_stack(x) (x) + #endif diff -purN step1/include/asm-frv/system.h step2/include/asm-frv/system.h --- step1/include/asm-frv/system.h 2005-01-26 18:24:39.000000000 +0100 +++ step2/include/asm-frv/system.h 2005-01-27 21:16:46.000000000 +0100 @@ -120,4 +120,6 @@ do { \ extern void die_if_kernel(const char *, ...) __attribute__((format(printf, 1, 2))); extern void free_initmem(void); +#define arch_align_stack(x) (x) + #endif /* _ASM_SYSTEM_H */ diff -purN step1/include/asm-h8300/system.h step2/include/asm-h8300/system.h --- step1/include/asm-h8300/system.h 2004-12-24 22:34:33.000000000 +0100 +++ step2/include/asm-h8300/system.h 2005-01-27 21:16:49.000000000 +0100 @@ -144,4 +144,6 @@ static inline unsigned long __xchg(unsig asm("jmp @@0"); \ }) +#define arch_align_stack(x) (x) + #endif /* _H8300_SYSTEM_H */ diff -purN step1/include/asm-i386/system.h step2/include/asm-i386/system.h --- step1/include/asm-i386/system.h 2005-01-26 18:24:39.000000000 +0100 +++ step2/include/asm-i386/system.h 2005-01-27 21:13:41.000000000 +0100 @@ -468,4 +468,6 @@ void enable_hlt(void); extern int es7000_plat; void cpu_idle_wait(void); +extern unsigned long arch_align_stack(unsigned long sp); + #endif diff -purN step1/include/asm-ia64/system.h step2/include/asm-ia64/system.h --- step1/include/asm-ia64/system.h 2005-01-26 18:24:39.000000000 +0100 +++ step2/include/asm-ia64/system.h 2005-01-27 21:17:08.000000000 +0100 @@ -285,6 +285,9 @@ do { \ #define ia64_platform_is(x) (strcmp(x, platform_name) == 0) void cpu_idle_wait(void); + +#define arch_align_stack(x) (x) + #endif /* __KERNEL__ */ #endif /* __ASSEMBLY__ */ diff -purN step1/include/asm-m32r/system.h step2/include/asm-m32r/system.h --- step1/include/asm-m32r/system.h 2005-01-26 18:24:39.000000000 +0100 +++ step2/include/asm-m32r/system.h 2005-01-27 21:17:13.000000000 +0100 @@ -294,4 +294,6 @@ static __inline__ unsigned long __xchg(u #define set_mb(var, value) do { xchg(&var, value); } while (0) #define set_wmb(var, value) do { var = value; wmb(); } while (0) +#define arch_align_stack(x) (x) + #endif /* _ASM_M32R_SYSTEM_H */ diff -purN step1/include/asm-m68k/system.h step2/include/asm-m68k/system.h --- step1/include/asm-m68k/system.h 2004-12-24 22:35:23.000000000 +0100 +++ step2/include/asm-m68k/system.h 2005-01-27 21:17:25.000000000 +0100 @@ -194,6 +194,8 @@ static inline unsigned long __cmpxchg(vo (unsigned long)(n),sizeof(*(ptr)))) #endif +#define arch_align_stack(x) (x) + #endif /* __KERNEL__ */ #endif /* _M68K_SYSTEM_H */ diff -purN step1/include/asm-m68knommu/system.h step2/include/asm-m68knommu/system.h --- step1/include/asm-m68knommu/system.h 2004-12-24 22:35:00.000000000 +0100 +++ step2/include/asm-m68knommu/system.h 2005-01-27 21:17:21.000000000 +0100 @@ -281,5 +281,6 @@ cmpxchg(volatile int *p, int old, int ne }) #endif #endif +#define arch_align_stack(x) (x) #endif /* _M68KNOMMU_SYSTEM_H */ diff -purN step1/include/asm-mips/system.h step2/include/asm-mips/system.h --- step1/include/asm-mips/system.h 2004-12-24 22:34:32.000000000 +0100 +++ step2/include/asm-mips/system.h 2005-01-27 21:17:29.000000000 +0100 @@ -433,4 +433,6 @@ do { \ #define finish_arch_switch(rq, prev) spin_unlock_irq(&(prev)->switch_lock) #define task_running(rq, p) ((rq)->curr == (p) || spin_is_locked(&(p)->switch_lock)) +#define arch_align_stack(x) (x) + #endif /* _ASM_SYSTEM_H */ diff -purN step1/include/asm-parisc/system.h step2/include/asm-parisc/system.h --- step1/include/asm-parisc/system.h 2005-01-26 18:24:39.000000000 +0100 +++ step2/include/asm-parisc/system.h 2005-01-27 21:17:36.000000000 +0100 @@ -205,4 +205,6 @@ extern spinlock_t pa_tlb_lock; #endif +#define arch_align_stack(x) (x) + #endif diff -purN step1/include/asm-ppc/system.h step2/include/asm-ppc/system.h --- step1/include/asm-ppc/system.h 2005-01-26 18:24:39.000000000 +0100 +++ step2/include/asm-ppc/system.h 2005-01-27 21:17:43.000000000 +0100 @@ -201,5 +201,7 @@ __cmpxchg(volatile void *ptr, unsigned l (unsigned long)_n_, sizeof(*(ptr))); \ }) +#define arch_align_stack(x) (x) + #endif /* __KERNEL__ */ #endif /* __PPC_SYSTEM_H */ diff -purN step1/include/asm-ppc64/system.h step2/include/asm-ppc64/system.h --- step1/include/asm-ppc64/system.h 2005-01-26 18:24:39.000000000 +0100 +++ step2/include/asm-ppc64/system.h 2005-01-27 21:17:39.000000000 +0100 @@ -300,5 +300,7 @@ __cmpxchg(volatile void *ptr, unsigned l */ #define NET_IP_ALIGN 0 +#define arch_align_stack(x) (x) + #endif /* __KERNEL__ */ #endif diff -purN step1/include/asm-s390/system.h step2/include/asm-s390/system.h --- step1/include/asm-s390/system.h 2005-01-26 18:24:39.000000000 +0100 +++ step2/include/asm-s390/system.h 2005-01-27 21:17:46.000000000 +0100 @@ -461,6 +461,8 @@ extern void (*_machine_restart)(char *co extern void (*_machine_halt)(void); extern void (*_machine_power_off)(void); +#define arch_align_stack(x) (x) + #endif /* __KERNEL__ */ #endif diff -purN step1/include/asm-sh/system.h step2/include/asm-sh/system.h --- step1/include/asm-sh/system.h 2004-12-24 22:35:28.000000000 +0100 +++ step2/include/asm-sh/system.h 2005-01-27 21:17:55.000000000 +0100 @@ -259,4 +259,6 @@ static __inline__ unsigned long __xchg(u void disable_hlt(void); void enable_hlt(void); +#define arch_align_stack(x) (x) + #endif diff -purN step1/include/asm-sh64/system.h step2/include/asm-sh64/system.h --- step1/include/asm-sh64/system.h 2004-12-24 22:35:15.000000000 +0100 +++ step2/include/asm-sh64/system.h 2005-01-27 21:17:51.000000000 +0100 @@ -191,4 +191,6 @@ extern void print_seg(char *file,int lin #define PL() printk("@ <%s,%s:%d>\n",__FILE__,__FUNCTION__,__LINE__) +#define arch_align_stack(x) (x) + #endif /* __ASM_SH64_SYSTEM_H */ diff -purN step1/include/asm-sparc/system.h step2/include/asm-sparc/system.h --- step1/include/asm-sparc/system.h 2004-12-24 22:35:23.000000000 +0100 +++ step2/include/asm-sparc/system.h 2005-01-27 21:18:04.000000000 +0100 @@ -257,4 +257,6 @@ extern void die_if_kernel(char *str, str #endif /* __ASSEMBLY__ */ +#define arch_align_stack(x) (x) + #endif /* !(__SPARC_SYSTEM_H) */ diff -purN step1/include/asm-sparc64/system.h step2/include/asm-sparc64/system.h --- step1/include/asm-sparc64/system.h 2004-12-24 22:33:48.000000000 +0100 +++ step2/include/asm-sparc64/system.h 2005-01-27 21:17:59.000000000 +0100 @@ -337,4 +337,6 @@ __cmpxchg(volatile void *ptr, unsigned l #endif /* !(__ASSEMBLY__) */ +#define arch_align_stack(x) (x) + #endif /* !(__SPARC64_SYSTEM_H) */ diff -purN step1/include/asm-v850/system.h step2/include/asm-v850/system.h --- step1/include/asm-v850/system.h 2004-12-24 22:35:23.000000000 +0100 +++ step2/include/asm-v850/system.h 2005-01-27 21:18:11.000000000 +0100 @@ -106,6 +106,9 @@ extern inline unsigned long __xchg (unsi local_irq_restore (flags); return tmp; + } +#define arch_align_stack(x) (x) + #endif /* __V850_SYSTEM_H__ */ diff -purN step1/include/asm-x86_64/system.h step2/include/asm-x86_64/system.h --- step1/include/asm-x86_64/system.h 2005-01-26 18:24:39.000000000 +0100 +++ step2/include/asm-x86_64/system.h 2005-01-27 21:13:49.000000000 +0100 @@ -338,4 +338,6 @@ void enable_hlt(void); #define HAVE_EAT_KEY void eat_key(void); +extern unsigned long arch_align_stack(unsigned long sp); + #endif - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/