From 1a530a6f23f7dca336311ef60c9ca26f3dc63688 Mon Sep 17 00:00:00 2001 From: David Daney Date: Tue, 22 Mar 2011 16:34:48 -0700 Subject: binfmt_elf: quiet GCC-4.6 'set but not used' warning in load_elf_binary() With GCC-4.6 we get warnings about things being 'set but not used'. In load_elf_binary() this can happen with reloc_func_desc if ELF_PLAT_INIT is defined, but doesn't use the reloc_func_desc argument. Quiet the warning/error by marking reloc_func_desc as __maybe_unused. Signed-off-by: David Daney Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/binfmt_elf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/binfmt_elf.c') diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index d5b640ba6cb..b2fae009a4b 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -570,7 +570,7 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) unsigned long elf_entry; unsigned long interp_load_addr = 0; unsigned long start_code, end_code, start_data, end_data; - unsigned long reloc_func_desc = 0; + unsigned long reloc_func_desc __maybe_unused = 0; int executable_stack = EXSTACK_DEFAULT; unsigned long def_flags = 0; struct { -- cgit v1.2.3-70-g09d2 From 31db58b3ab432f72ea76be58b12e6ffaf627d5db Mon Sep 17 00:00:00 2001 From: Stephen Wilson Date: Sun, 13 Mar 2011 15:49:15 -0400 Subject: mm: arch: make get_gate_vma take an mm_struct instead of a task_struct Morally, the presence of a gate vma is more an attribute of a particular mm than a particular task. Moreover, dropping the dependency on task_struct will help make both existing and future operations on mm's more flexible and convenient. Signed-off-by: Stephen Wilson Reviewed-by: Michel Lespinasse Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Signed-off-by: Al Viro --- arch/powerpc/kernel/vdso.c | 2 +- arch/s390/kernel/vdso.c | 2 +- arch/sh/kernel/vsyscall/vsyscall.c | 2 +- arch/x86/mm/init_64.c | 6 +++--- arch/x86/vdso/vdso32-setup.c | 11 ++++++----- fs/binfmt_elf.c | 2 +- fs/proc/task_mmu.c | 8 +++++--- include/linux/mm.h | 2 +- mm/memory.c | 4 ++-- mm/mlock.c | 4 ++-- 10 files changed, 23 insertions(+), 20 deletions(-) (limited to 'fs/binfmt_elf.c') diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index fd8728729ab..6169f175693 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -830,7 +830,7 @@ int in_gate_area(struct task_struct *task, unsigned long addr) return 0; } -struct vm_area_struct *get_gate_vma(struct task_struct *tsk) +struct vm_area_struct *get_gate_vma(struct mm_struct *mm) { return NULL; } diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c index f438d74dedb..d19f30504c6 100644 --- a/arch/s390/kernel/vdso.c +++ b/arch/s390/kernel/vdso.c @@ -347,7 +347,7 @@ int in_gate_area(struct task_struct *task, unsigned long addr) return 0; } -struct vm_area_struct *get_gate_vma(struct task_struct *tsk) +struct vm_area_struct *get_gate_vma(struct mm_struct *mm) { return NULL; } diff --git a/arch/sh/kernel/vsyscall/vsyscall.c b/arch/sh/kernel/vsyscall/vsyscall.c index 242117cbad6..3f9b6f41813 100644 --- a/arch/sh/kernel/vsyscall/vsyscall.c +++ b/arch/sh/kernel/vsyscall/vsyscall.c @@ -94,7 +94,7 @@ const char *arch_vma_name(struct vm_area_struct *vma) return NULL; } -struct vm_area_struct *get_gate_vma(struct task_struct *task) +struct vm_area_struct *get_gate_vma(struct mm_struct *mm) { return NULL; } diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 0aa34669ed3..dd4809b5844 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -861,10 +861,10 @@ static struct vm_area_struct gate_vma = { .vm_flags = VM_READ | VM_EXEC }; -struct vm_area_struct *get_gate_vma(struct task_struct *tsk) +struct vm_area_struct *get_gate_vma(struct mm_struct *mm) { #ifdef CONFIG_IA32_EMULATION - if (test_tsk_thread_flag(tsk, TIF_IA32)) + if (!mm || mm->context.ia32_compat) return NULL; #endif return &gate_vma; @@ -872,7 +872,7 @@ struct vm_area_struct *get_gate_vma(struct task_struct *tsk) int in_gate_area(struct task_struct *task, unsigned long addr) { - struct vm_area_struct *vma = get_gate_vma(task); + struct vm_area_struct *vma = get_gate_vma(task->mm); if (!vma) return 0; diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c index 36df991985b..1f651f6bdf6 100644 --- a/arch/x86/vdso/vdso32-setup.c +++ b/arch/x86/vdso/vdso32-setup.c @@ -417,11 +417,12 @@ const char *arch_vma_name(struct vm_area_struct *vma) return NULL; } -struct vm_area_struct *get_gate_vma(struct task_struct *tsk) +struct vm_area_struct *get_gate_vma(struct mm_struct *mm) { - struct mm_struct *mm = tsk->mm; - - /* Check to see if this task was created in compat vdso mode */ + /* + * Check to see if the corresponding task was created in compat vdso + * mode. + */ if (mm && mm->context.vdso == (void *)VDSO_HIGH_BASE) return &gate_vma; return NULL; @@ -429,7 +430,7 @@ struct vm_area_struct *get_gate_vma(struct task_struct *tsk) int in_gate_area(struct task_struct *task, unsigned long addr) { - const struct vm_area_struct *vma = get_gate_vma(task); + const struct vm_area_struct *vma = get_gate_vma(task->mm); return vma && addr >= vma->vm_start && addr < vma->vm_end; } diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index d5b640ba6cb..bbabdcce117 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1906,7 +1906,7 @@ static int elf_core_dump(struct coredump_params *cprm) segs = current->mm->map_count; segs += elf_core_extra_phdrs(); - gate_vma = get_gate_vma(current); + gate_vma = get_gate_vma(current->mm); if (gate_vma != NULL) segs++; diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 8fed0f88fbf..e73314afc53 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -126,7 +126,7 @@ static void *m_start(struct seq_file *m, loff_t *pos) return mm; down_read(&mm->mmap_sem); - tail_vma = get_gate_vma(priv->task); + tail_vma = get_gate_vma(priv->task->mm); priv->tail_vma = tail_vma; /* Start with last addr hint */ @@ -277,7 +277,8 @@ static int show_map(struct seq_file *m, void *v) show_map_vma(m, vma); if (m->count < m->size) /* vma is copied successfully */ - m->version = (vma != get_gate_vma(task))? vma->vm_start: 0; + m->version = (vma != get_gate_vma(task->mm)) + ? vma->vm_start : 0; return 0; } @@ -436,7 +437,8 @@ static int show_smap(struct seq_file *m, void *v) (unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0); if (m->count < m->size) /* vma is copied successfully */ - m->version = (vma != get_gate_vma(task)) ? vma->vm_start : 0; + m->version = (vma != get_gate_vma(task->mm)) + ? vma->vm_start : 0; return 0; } diff --git a/include/linux/mm.h b/include/linux/mm.h index 581703d86fb..18b4a6358ab 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1578,7 +1578,7 @@ static inline bool kernel_page_present(struct page *page) { return true; } #endif /* CONFIG_HIBERNATION */ #endif -extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk); +extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm); #ifdef __HAVE_ARCH_GATE_AREA int in_gate_area_no_task(unsigned long addr); int in_gate_area(struct task_struct *task, unsigned long addr); diff --git a/mm/memory.c b/mm/memory.c index e48945ab362..b6dc3709743 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1488,7 +1488,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, vma = find_extend_vma(mm, start); if (!vma && in_gate_area(tsk, start)) { unsigned long pg = start & PAGE_MASK; - struct vm_area_struct *gate_vma = get_gate_vma(tsk); + struct vm_area_struct *gate_vma = get_gate_vma(tsk->mm); pgd_t *pgd; pud_t *pud; pmd_t *pmd; @@ -3496,7 +3496,7 @@ static int __init gate_vma_init(void) __initcall(gate_vma_init); #endif -struct vm_area_struct *get_gate_vma(struct task_struct *tsk) +struct vm_area_struct *get_gate_vma(struct mm_struct *mm) { #ifdef AT_SYSINFO_EHDR return &gate_vma; diff --git a/mm/mlock.c b/mm/mlock.c index c3924c7f00b..2689a08c79a 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -237,7 +237,7 @@ long mlock_vma_pages_range(struct vm_area_struct *vma, if (!((vma->vm_flags & (VM_DONTEXPAND | VM_RESERVED)) || is_vm_hugetlb_page(vma) || - vma == get_gate_vma(current))) { + vma == get_gate_vma(current->mm))) { __mlock_vma_pages_range(vma, start, end, NULL); @@ -332,7 +332,7 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev, int lock = newflags & VM_LOCKED; if (newflags == vma->vm_flags || (vma->vm_flags & VM_SPECIAL) || - is_vm_hugetlb_page(vma) || vma == get_gate_vma(current)) + is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm)) goto out; /* don't set VM_LOCKED, don't count */ pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); -- cgit v1.2.3-70-g09d2 From 4471a675dfc7ca676c165079e91c712b09dc9ce4 Mon Sep 17 00:00:00 2001 From: Jiri Kosina Date: Thu, 14 Apr 2011 15:22:09 -0700 Subject: brk: COMPAT_BRK: fix detection of randomized brk 5520e89 ("brk: fix min_brk lower bound computation for COMPAT_BRK") tried to get the whole logic of brk randomization for legacy (libc5-based) applications finally right. It turns out that the way to detect whether brk has actually been randomized in the end or not introduced by that patch still doesn't work for those binaries, as reported by Geert: : /sbin/init from my old m68k ramdisk exists prematurely. : : Before the patch: : : | brk(0x80005c8e) = 0x80006000 : : After the patch: : : | brk(0x80005c8e) = 0x80005c8e : : Old libc5 considers brk() to have failed if the return value is not : identical to the requested value. I don't like it, but currently see no better option than a bit flag in task_struct to catch the CONFIG_COMPAT_BRK && randomize_va_space == 2 case. Signed-off-by: Jiri Kosina Tested-by: Geert Uytterhoeven Reported-by: Geert Uytterhoeven Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/binfmt_elf.c | 6 +++++- include/linux/sched.h | 3 +++ mm/mmap.c | 2 +- 3 files changed, 9 insertions(+), 2 deletions(-) (limited to 'fs/binfmt_elf.c') diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index f34078d702d..303983fabfd 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -941,9 +941,13 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) current->mm->start_stack = bprm->p; #ifdef arch_randomize_brk - if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) + if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) { current->mm->brk = current->mm->start_brk = arch_randomize_brk(current->mm); +#ifdef CONFIG_COMPAT_BRK + current->brk_randomized = 1; +#endif + } #endif if (current->personality & MMAP_PAGE_ZERO) { diff --git a/include/linux/sched.h b/include/linux/sched.h index 4ec2c027e92..18d63cea284 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1254,6 +1254,9 @@ struct task_struct { #endif struct mm_struct *mm, *active_mm; +#ifdef CONFIG_COMPAT_BRK + unsigned brk_randomized:1; +#endif #if defined(SPLIT_RSS_COUNTING) struct task_rss_stat rss_stat; #endif diff --git a/mm/mmap.c b/mm/mmap.c index 8c05e5b43b6..e27e0cf0de0 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -259,7 +259,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk) * randomize_va_space to 2, which will still cause mm->start_brk * to be arbitrarily shifted */ - if (mm->start_brk > PAGE_ALIGN(mm->end_data)) + if (current->brk_randomized) min_brk = mm->start_brk; else min_brk = mm->end_data; -- cgit v1.2.3-70-g09d2