diff options
Diffstat (limited to 'linux-2.6-i386-nx-emulation.patch')
-rw-r--r-- | linux-2.6-i386-nx-emulation.patch | 628 |
1 files changed, 628 insertions, 0 deletions
diff --git a/linux-2.6-i386-nx-emulation.patch b/linux-2.6-i386-nx-emulation.patch new file mode 100644 index 000000000..a47e99d47 --- /dev/null +++ b/linux-2.6-i386-nx-emulation.patch @@ -0,0 +1,628 @@ +--- a/arch/x86/include/asm/desc.h ++++ b/arch/x86/include/asm/desc.h +@@ -5,6 +5,7 @@ + #include <asm/ldt.h> + #include <asm/mmu.h> + #include <linux/smp.h> ++#include <linux/mm_types.h> + + static inline void fill_ldt(struct desc_struct *desc, + const struct user_desc *info) +@@ -93,6 +94,9 @@ static inline int desc_empty(const void *ptr) + + #define load_TLS(t, cpu) native_load_tls(t, cpu) + #define set_ldt native_set_ldt ++#ifdef CONFIG_X86_32 ++#define load_user_cs_desc native_load_user_cs_desc ++#endif /*CONFIG_X86_32*/ + + #define write_ldt_entry(dt, entry, desc) \ + native_write_ldt_entry(dt, entry, desc) +@@ -392,4 +396,25 @@ static inline void set_system_intr_gate_ist(int n, void *addr, unsigned ist) + _set_gate(n, GATE_INTERRUPT, addr, 0x3, ist, __KERNEL_CS); + } + ++#ifdef CONFIG_X86_32 ++static inline void set_user_cs(struct desc_struct *desc, unsigned long limit) ++{ ++ limit = (limit - 1) / PAGE_SIZE; ++ desc->a = limit & 0xffff; ++ desc->b = (limit & 0xf0000) | 0x00c0fb00; ++} ++ ++static inline void native_load_user_cs_desc(int cpu, struct mm_struct *mm) ++{ ++ get_cpu_gdt_table(cpu)[GDT_ENTRY_DEFAULT_USER_CS] = (mm)->context.user_cs; ++} ++ ++#define arch_add_exec_range arch_add_exec_range ++#define arch_remove_exec_range arch_remove_exec_range ++#define arch_flush_exec_range arch_flush_exec_range ++extern void arch_add_exec_range(struct mm_struct *mm, unsigned long limit); ++extern void arch_remove_exec_range(struct mm_struct *mm, unsigned long limit); ++extern void arch_flush_exec_range(struct mm_struct *mm); ++#endif /* CONFIG_X86_32 */ ++ + #endif /* _ASM_X86_DESC_H */ +--- a/arch/x86/include/asm/mmu.h ++++ b/arch/x86/include/asm/mmu.h +@@ -7,12 +7,19 @@ + /* + * The x86 doesn't have a mmu context, but + * we put the segment information here. ++ * ++ * exec_limit is used to track the range PROT_EXEC ++ * mappings span. + */ + typedef struct { + void *ldt; + int size; + struct mutex lock; + void *vdso; ++#ifdef CONFIG_X86_32 ++ struct desc_struct user_cs; ++ unsigned long exec_limit; ++#endif + } mm_context_t; + + #ifdef CONFIG_SMP +--- a/arch/x86/include/asm/paravirt.h ++++ b/arch/x86/include/asm/paravirt.h +@@ -289,6 +289,12 @@ static inline void set_ldt(const void *addr, unsigned entries) + { + PVOP_VCALL2(pv_cpu_ops.set_ldt, addr, entries); + } ++#ifdef CONFIG_X86_32 ++static inline void load_user_cs_desc(unsigned int cpu, struct mm_struct *mm) ++{ ++ PVOP_VCALL2(pv_cpu_ops.load_user_cs_desc, cpu, mm); ++} ++#endif /*CONFIG_X86_32*/ + static inline void store_gdt(struct desc_ptr *dtr) + { + PVOP_VCALL1(pv_cpu_ops.store_gdt, dtr); +--- a/arch/x86/include/asm/paravirt_types.h ++++ b/arch/x86/include/asm/paravirt_types.h +@@ -118,6 +118,9 @@ struct pv_cpu_ops { + void (*store_gdt)(struct desc_ptr *); + void (*store_idt)(struct desc_ptr *); + void (*set_ldt)(const void *desc, unsigned entries); ++#ifdef CONFIG_X86_32 ++ void (*load_user_cs_desc)(int cpu, struct mm_struct *mm); ++#endif + unsigned long (*store_tr)(void); + void (*load_tls)(struct thread_struct *t, unsigned int cpu); + #ifdef CONFIG_X86_64 +--- a/arch/x86/kernel/cpu/common.c ++++ b/arch/x86/kernel/cpu/common.c +@@ -802,6 +802,22 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c) + /* Filter out anything that depends on CPUID levels we don't have */ + filter_cpuid_features(c, true); + ++#ifdef CONFIG_X86_32 ++ /* ++ * emulation of NX with segment limits unfortunately means ++ * we have to disable the fast system calls, due to the way that ++ * sysexit clears the segment limits on return. ++ * If we have either disabled exec-shield on the boot command line, ++ * or we have NX, then we don't need to do this. ++ */ ++ if (exec_shield != 0) { ++#ifdef CONFIG_X86_PAE ++ if (!test_cpu_cap(c, X86_FEATURE_NX)) ++#endif ++ clear_cpu_cap(c, X86_FEATURE_SEP); ++ } ++#endif ++ + /* If the model name is still unset, do table lookup. */ + if (!c->x86_model_id[0]) { + const char *p; +--- a/arch/x86/kernel/paravirt.c ++++ b/arch/x86/kernel/paravirt.c +@@ -345,6 +345,9 @@ struct pv_cpu_ops pv_cpu_ops = { + .read_tscp = native_read_tscp, + .load_tr_desc = native_load_tr_desc, + .set_ldt = native_set_ldt, ++#ifdef CONFIG_X86_32 ++ .load_user_cs_desc = native_load_user_cs_desc, ++#endif /*CONFIG_X86_32*/ + .load_gdt = native_load_gdt, + .load_idt = native_load_idt, + .store_gdt = native_store_gdt, +--- a/arch/x86/kernel/process_32.c ++++ b/arch/x86/kernel/process_32.c +@@ -243,7 +243,10 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, + void + start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) + { ++ int cpu; ++ + set_user_gs(regs, 0); ++ + regs->fs = 0; + set_fs(USER_DS); + regs->ds = __USER_DS; +@@ -252,6 +255,11 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) + regs->cs = __USER_CS; + regs->ip = new_ip; + regs->sp = new_sp; ++ ++ cpu = get_cpu(); ++ load_user_cs_desc(cpu, current->mm); ++ put_cpu(); ++ + /* + * Free the old FP and other extended state + */ +@@ -311,6 +319,9 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) + if (preload_fpu) + prefetch(next->fpu.state); + ++ if (next_p->mm) ++ load_user_cs_desc(cpu, next_p->mm); ++ + /* + * Reload esp0. + */ +@@ -404,3 +415,40 @@ unsigned long get_wchan(struct task_struct *p) + return 0; + } + ++static void modify_cs(struct mm_struct *mm, unsigned long limit) ++{ ++ mm->context.exec_limit = limit; ++ set_user_cs(&mm->context.user_cs, limit); ++ if (mm == current->mm) { ++ int cpu; ++ ++ cpu = get_cpu(); ++ load_user_cs_desc(cpu, mm); ++ put_cpu(); ++ } ++} ++ ++void arch_add_exec_range(struct mm_struct *mm, unsigned long limit) ++{ ++ if (limit > mm->context.exec_limit) ++ modify_cs(mm, limit); ++} ++ ++void arch_remove_exec_range(struct mm_struct *mm, unsigned long old_end) ++{ ++ struct vm_area_struct *vma; ++ unsigned long limit = PAGE_SIZE; ++ ++ if (old_end == mm->context.exec_limit) { ++ for (vma = mm->mmap; vma; vma = vma->vm_next) ++ if ((vma->vm_flags & VM_EXEC) && (vma->vm_end > limit)) ++ limit = vma->vm_end; ++ modify_cs(mm, limit); ++ } ++} ++ ++void arch_flush_exec_range(struct mm_struct *mm) ++{ ++ mm->context.exec_limit = 0; ++ set_user_cs(&mm->context.user_cs, 0); ++} +--- a/arch/x86/kernel/traps.c ++++ b/arch/x86/kernel/traps.c +@@ -109,6 +109,78 @@ static inline void preempt_conditional_cli(struct pt_regs *regs) + dec_preempt_count(); + } + ++#ifdef CONFIG_X86_32 ++static inline int ++__compare_user_cs_desc(const struct desc_struct *desc1, ++ const struct desc_struct *desc2) ++{ ++ return ((desc1->limit0 != desc2->limit0) || ++ (desc1->limit != desc2->limit) || ++ (desc1->base0 != desc2->base0) || ++ (desc1->base1 != desc2->base1) || ++ (desc1->base2 != desc2->base2)); ++} ++ ++/* ++ * lazy-check for CS validity on exec-shield binaries: ++ * ++ * the original non-exec stack patch was written by ++ * Solar Designer <solar at openwall.com>. Thanks! ++ */ ++static int ++check_lazy_exec_limit(int cpu, struct pt_regs *regs, long error_code) ++{ ++ struct desc_struct *desc1, *desc2; ++ struct vm_area_struct *vma; ++ unsigned long limit; ++ ++ if (current->mm == NULL) ++ return 0; ++ ++ limit = -1UL; ++ if (current->mm->context.exec_limit != -1UL) { ++ limit = PAGE_SIZE; ++ spin_lock(¤t->mm->page_table_lock); ++ for (vma = current->mm->mmap; vma; vma = vma->vm_next) ++ if ((vma->vm_flags & VM_EXEC) && (vma->vm_end > limit)) ++ limit = vma->vm_end; ++ vma = get_gate_vma(current); ++ if (vma && (vma->vm_flags & VM_EXEC) && (vma->vm_end > limit)) ++ limit = vma->vm_end; ++ spin_unlock(¤t->mm->page_table_lock); ++ if (limit >= TASK_SIZE) ++ limit = -1UL; ++ current->mm->context.exec_limit = limit; ++ } ++ set_user_cs(¤t->mm->context.user_cs, limit); ++ ++ desc1 = ¤t->mm->context.user_cs; ++ desc2 = get_cpu_gdt_table(cpu) + GDT_ENTRY_DEFAULT_USER_CS; ++ ++ if (__compare_user_cs_desc(desc1, desc2)) { ++ /* ++ * The CS was not in sync - reload it and retry the ++ * instruction. If the instruction still faults then ++ * we won't hit this branch next time around. ++ */ ++ if (print_fatal_signals >= 2) { ++ printk(KERN_ERR "#GPF fixup (%ld[seg:%lx]) at %08lx, CPU#%d.\n", ++ error_code, error_code/8, regs->ip, ++ smp_processor_id()); ++ printk(KERN_ERR "exec_limit: %08lx, user_cs: %08x/%08x, CPU_cs: %08x/%08x.\n", ++ current->mm->context.exec_limit, ++ desc1->a, desc1->b, desc2->a, desc2->b); ++ } ++ ++ load_user_cs_desc(cpu, current->mm); ++ ++ return 1; ++ } ++ ++ return 0; ++} ++#endif ++ + static void __kprobes + do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, + long error_code, siginfo_t *info) +@@ -265,6 +337,29 @@ do_general_protection(struct pt_regs *regs, long error_code) + if (!user_mode(regs)) + goto gp_in_kernel; + ++#ifdef CONFIG_X86_32 ++{ ++ int cpu; ++ int ok; ++ ++ cpu = get_cpu(); ++ ok = check_lazy_exec_limit(cpu, regs, error_code); ++ put_cpu(); ++ ++ if (ok) ++ return; ++ ++ if (print_fatal_signals) { ++ printk(KERN_ERR "#GPF(%ld[seg:%lx]) at %08lx, CPU#%d.\n", ++ error_code, error_code/8, regs->ip, smp_processor_id()); ++ printk(KERN_ERR "exec_limit: %08lx, user_cs: %08x/%08x.\n", ++ current->mm->context.exec_limit, ++ current->mm->context.user_cs.a, ++ current->mm->context.user_cs.b); ++ } ++} ++#endif /*CONFIG_X86_32*/ ++ + tsk->thread.error_code = error_code; + tsk->thread.trap_no = 13; + +@@ -792,19 +887,37 @@ do_device_not_available(struct pt_regs *regs, long error_code) + } + + #ifdef CONFIG_X86_32 ++/* ++ * The fixup code for errors in iret jumps to here (iret_exc). It loses ++ * the original trap number and erorr code. The bogus trap 32 and error ++ * code 0 are what the vanilla kernel delivers via: ++ * DO_ERROR_INFO(32, SIGSEGV, "iret exception", iret_error, ILL_BADSTK, 0, 1) ++ * ++ * NOTE: Because of the final "1" in the macro we need to enable interrupts. ++ * ++ * In case of a general protection fault in the iret instruction, we ++ * need to check for a lazy CS update for exec-shield. ++ */ + dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) + { +- siginfo_t info; ++ int ok; ++ int cpu; ++ + local_irq_enable(); + +- info.si_signo = SIGILL; +- info.si_errno = 0; +- info.si_code = ILL_BADSTK; +- info.si_addr = NULL; +- if (notify_die(DIE_TRAP, "iret exception", +- regs, error_code, 32, SIGILL) == NOTIFY_STOP) +- return; +- do_trap(32, SIGILL, "iret exception", regs, error_code, &info); ++ cpu = get_cpu(); ++ ok = check_lazy_exec_limit(cpu, regs, error_code); ++ put_cpu(); ++ ++ if (!ok && notify_die(DIE_TRAP, "iret exception", regs, ++ error_code, 32, SIGSEGV) != NOTIFY_STOP) { ++ siginfo_t info; ++ info.si_signo = SIGSEGV; ++ info.si_errno = 0; ++ info.si_code = ILL_BADSTK; ++ info.si_addr = 0; ++ do_trap(32, SIGSEGV, "iret exception", regs, error_code, &info); ++ } + } + #endif + +--- a/arch/x86/mm/setup_nx.c ++++ b/arch/x86/mm/setup_nx.c +@@ -1,3 +1,4 @@ ++#include <linux/sched.h> + #include <linux/spinlock.h> + #include <linux/errno.h> + #include <linux/init.h> +@@ -23,6 +24,7 @@ static int __init noexec_setup(char *str) + disable_nx = 0; + } else if (!strncmp(str, "off", 3)) { + disable_nx = 1; ++ exec_shield = 0; + } + x86_configure_nx(); + return 0; +@@ -40,6 +42,10 @@ void __cpuinit x86_configure_nx(void) + void __init x86_report_nx(void) + { + if (!cpu_has_nx) { ++ if (exec_shield) ++ printk(KERN_INFO "Using x86 segment limits to approximate NX protection\n"); ++ else ++ + printk(KERN_NOTICE "Notice: NX (Execute Disable) protection " + "missing in CPU or disabled in BIOS!\n"); + } else { +--- a/arch/x86/mm/tlb.c ++++ b/arch/x86/mm/tlb.c +@@ -6,6 +6,7 @@ + #include <linux/interrupt.h> + #include <linux/module.h> + ++#include <asm/desc.h> + #include <asm/tlbflush.h> + #include <asm/mmu_context.h> + #include <asm/cache.h> +@@ -131,6 +132,12 @@ void smp_invalidate_interrupt(struct pt_regs *regs) + union smp_flush_state *f; + + cpu = smp_processor_id(); ++ ++#ifdef CONFIG_X86_32 ++ if (current->active_mm) ++ load_user_cs_desc(cpu, current->active_mm); ++#endif ++ + /* + * orig_rax contains the negated interrupt vector. + * Use that to determine where the sender put the data. +--- a/arch/x86/xen/enlighten.c ++++ b/arch/x86/xen/enlighten.c +@@ -335,6 +335,24 @@ static void xen_set_ldt(const void *addr, unsigned entries) + xen_mc_issue(PARAVIRT_LAZY_CPU); + } + ++#ifdef CONFIG_X86_32 ++static void xen_load_user_cs_desc(int cpu, struct mm_struct *mm) ++{ ++ void *gdt; ++ xmaddr_t mgdt; ++ u64 descriptor; ++ struct desc_struct user_cs; ++ ++ gdt = &get_cpu_gdt_table(cpu)[GDT_ENTRY_DEFAULT_USER_CS]; ++ mgdt = virt_to_machine(gdt); ++ ++ user_cs = mm->context.user_cs; ++ descriptor = (u64) user_cs.a | ((u64) user_cs.b) << 32; ++ ++ HYPERVISOR_update_descriptor(mgdt.maddr, descriptor); ++} ++#endif /*CONFIG_X86_32*/ ++ + static void xen_load_gdt(const struct desc_ptr *dtr) + { + unsigned long va = dtr->address; +@@ -961,6 +979,9 @@ static const struct pv_cpu_ops xen_cpu_ops __initdata = { + + .load_tr_desc = paravirt_nop, + .set_ldt = xen_set_ldt, ++#ifdef CONFIG_X86_32 ++ .load_user_cs_desc = xen_load_user_cs_desc, ++#endif /*CONFIG_X86_32*/ + .load_gdt = xen_load_gdt, + .load_idt = xen_load_idt, + .load_tls = xen_load_tls, +--- a/fs/binfmt_elf.c ++++ b/fs/binfmt_elf.c +@@ -717,6 +722,15 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) + if (retval) + goto out_free_dentry; + ++#ifdef CONFIG_X86_32 ++ /* ++ * Turn off the CS limit completely if exec-shield disabled or ++ * NX active: ++ */ ++ if (!exec_shield || executable_stack != EXSTACK_DISABLE_X || (__supported_pte_mask & _PAGE_NX)) ++ arch_add_exec_range(current->mm, -1); ++#endif ++ + /* OK, This is the point of no return */ + current->flags &= ~PF_FORKNOEXEC; + current->mm->def_flags = def_flags; +--- a/include/linux/sched.h ++++ b/include/linux/sched.h +@@ -101,6 +101,9 @@ struct bio_list; + struct fs_struct; + struct perf_event_context; + ++extern int exec_shield; ++extern int print_fatal_signals; ++ + /* + * List of flags we want to share for kernel threads, + * if only because they are not used by them anyway. +--- a/kernel/sysctl.c ++++ b/kernel/sysctl.c +@@ -101,6 +101,17 @@ extern int sysctl_nr_open_min, sysctl_nr_open_max; + #ifndef CONFIG_MMU + extern int sysctl_nr_trim_pages; + #endif ++ ++int exec_shield = 1; ++ ++static int __init setup_exec_shield(char *str) ++{ ++ get_option(&str, &exec_shield); ++ ++ return 1; ++} ++__setup("exec-shield=", setup_exec_shield); ++ + #ifdef CONFIG_BLOCK + extern int blk_iopoll_enabled; + #endif +@@ -428,6 +448,16 @@ static struct ctl_table kern_table[] = { + .mode = 0644, + .proc_handler = proc_dointvec, + }, ++#ifdef CONFIG_X86_32 ++ { ++ .procname = "exec-shield", ++ .data = &exec_shield, ++ .maxlen = sizeof(int), ++ .mode = 0644, ++ .proc_handler = &proc_dointvec, ++ }, ++#endif ++ + #ifdef CONFIG_PROC_SYSCTL + { + .procname = "tainted", +--- b/mm/mmap.c ++++ b/mm/mmap.c +@@ -44,6 +45,18 @@ + #define arch_rebalance_pgtables(addr, len) (addr) + #endif + ++/* No sane architecture will #define these to anything else */ ++#ifndef arch_add_exec_range ++#define arch_add_exec_range(mm, limit) do { ; } while (0) ++#endif ++#ifndef arch_flush_exec_range ++#define arch_flush_exec_range(mm) do { ; } while (0) ++#endif ++#ifndef arch_remove_exec_range ++#define arch_remove_exec_range(mm, limit) do { ; } while (0) ++#endif ++ ++ + static void unmap_region(struct mm_struct *mm, + struct vm_area_struct *vma, struct vm_area_struct *prev, + unsigned long start, unsigned long end); +@@ -388,6 +401,8 @@ + __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, + struct vm_area_struct *prev, struct rb_node *rb_parent) + { ++ if (vma->vm_flags & VM_EXEC) ++ arch_add_exec_range(mm, vma->vm_end); + if (prev) { + vma->vm_next = prev->vm_next; + prev->vm_next = vma; +@@ -489,6 +504,8 @@ + rb_erase(&vma->vm_rb, &mm->mm_rb); + if (mm->mmap_cache == vma) + mm->mmap_cache = prev; ++ if (vma->vm_flags & VM_EXEC) ++ arch_remove_exec_range(mm, vma->vm_end); + } + + /* +@@ -790,6 +807,8 @@ + } else /* cases 2, 5, 7 */ + err = vma_adjust(prev, prev->vm_start, + end, prev->vm_pgoff, NULL); ++ if (prev->vm_flags & VM_EXEC) ++ arch_add_exec_range(mm, prev->vm_end); + if (err) + return NULL; + return prev; +@@ -1966,10 +2075,14 @@ + if (new->vm_ops && new->vm_ops->open) + new->vm_ops->open(new); + +- if (new_below) ++ if (new_below) { ++ unsigned long old_end = vma->vm_end; ++ + err = vma_adjust(vma, addr, vma->vm_end, vma->vm_pgoff + + ((addr - new->vm_start) >> PAGE_SHIFT), new); +- else ++ if (vma->vm_flags & VM_EXEC) ++ arch_remove_exec_range(mm, old_end); ++ } else + err = vma_adjust(vma, vma->vm_start, addr, vma->vm_pgoff, new); + + /* Success. */ +@@ -2254,6 +2367,7 @@ + + free_pgtables(tlb, vma, FIRST_USER_ADDRESS, 0); + tlb_finish_mmu(tlb, 0, end); ++ arch_flush_exec_range(mm); + + /* + * Walk the list again, actually closing and freeing it, +--- a/mm/mprotect.c ++++ b/mm/mprotect.c +@@ -25,9 +25,14 @@ + #include <linux/perf_event.h> + #include <asm/uaccess.h> + #include <asm/pgtable.h> ++#include <asm/pgalloc.h> + #include <asm/cacheflush.h> + #include <asm/tlbflush.h> + ++#ifndef arch_remove_exec_range ++#define arch_remove_exec_range(mm, limit) do { ; } while (0) ++#endif ++ + #ifndef pgprot_modify + static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) + { +@@ -138,7 +143,7 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, + struct mm_struct *mm = vma->vm_mm; + unsigned long oldflags = vma->vm_flags; + long nrpages = (end - start) >> PAGE_SHIFT; +- unsigned long charged = 0; ++ unsigned long charged = 0, old_end = vma->vm_end; + pgoff_t pgoff; + int error; + int dirty_accountable = 0; +@@ -203,6 +208,9 @@ success: + dirty_accountable = 1; + } + ++ if (oldflags & VM_EXEC) ++ arch_remove_exec_range(current->mm, old_end); ++ + mmu_notifier_invalidate_range_start(mm, start, end); + if (is_vm_hugetlb_page(vma)) + hugetlb_change_protection(vma, start, end, vma->vm_page_prot); |