[PATCH v21 012/100] c/r: extend arch_setup_additional_pages()
From: Oren Laadan <hidden>
Date: 2010-05-01 14:50:33
Also in:
linux-s390, lkml
Subsystem:
exec & binfmt api, elf, filesystems (vfs and infrastructure), linux for powerpc (32-bit and 64-bit), s390 architecture, superh, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Kees Cook, Alexander Viro, Christian Brauner, Madhavan Srinivasan, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Yoshinori Sato, Rich Felker, John Paul Adrian Glaubitz, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Alexey Dobriyan <redacted> Add "start" argument, to request to map vDSO to a specific place, and fail the operation if not. This is useful for restart(2) to ensure that memory layout is restore exactly as needed. Changelog[v19]: - [serge hallyn] Fix potential use-before-set ret Changelog[v2]: - [ntl] powerpc: vdso build fix (ckpt-v17) Cc: x86@kernel.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@ozlabs.org Signed-off-by: Alexey Dobriyan <redacted> Signed-off-by: Oren Laadan <redacted> --- arch/powerpc/include/asm/elf.h | 1 + arch/powerpc/kernel/vdso.c | 13 ++++++++++++- arch/s390/include/asm/elf.h | 2 +- arch/s390/kernel/vdso.c | 13 ++++++++++++- arch/sh/include/asm/elf.h | 1 + arch/sh/kernel/vsyscall/vsyscall.c | 2 +- arch/x86/include/asm/elf.h | 3 ++- arch/x86/vdso/vdso32-setup.c | 9 +++++++-- arch/x86/vdso/vma.c | 11 ++++++++--- fs/binfmt_elf.c | 2 +- 10 files changed, 46 insertions(+), 11 deletions(-)
diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h
index c376eda..0b06255 100644
--- a/arch/powerpc/include/asm/elf.h
+++ b/arch/powerpc/include/asm/elf.h@@ -266,6 +266,7 @@ extern int ucache_bsize; #define ARCH_HAS_SETUP_ADDITIONAL_PAGES struct linux_binprm; extern int arch_setup_additional_pages(struct linux_binprm *bprm, + unsigned long start, int uses_interp); #define VDSO_AUX_ENT(a,b) NEW_AUX_ENT(a,b);
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index d84d192..74210ab 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c@@ -188,7 +188,8 @@ static void dump_vdso_pages(struct vm_area_struct * vma) * This is called from binfmt_elf, we create the special vma for the * vDSO and insert it into the mm struct tree */ -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) +int arch_setup_additional_pages(struct linux_binprm *bprm, + unsigned long start, int uses_interp) { struct mm_struct *mm = current->mm; struct page **vdso_pagelist;
@@ -220,6 +221,10 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) vdso_base = VDSO32_MBASE; #endif + /* in case restart(2) mandates a specific location */ + if (start) + vdso_base = start; + current->mm->context.vdso_base = 0; /* vDSO has a problem and was disabled, just don't "enable" it for the
@@ -249,6 +254,12 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) /* Add required alignment. */ vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT); + /* for restart(2), double check that we got we asked for */ + if (start && vdso_base != start) { + rc = -EBUSY; + goto fail_mmapsem; + } + /* * Put vDSO base into mm struct. We need to do this before calling * install_special_mapping or the perf counter mmap tracking code
diff --git a/arch/s390/include/asm/elf.h b/arch/s390/include/asm/elf.h
index 354d426..5081938 100644
--- a/arch/s390/include/asm/elf.h
+++ b/arch/s390/include/asm/elf.h@@ -216,6 +216,6 @@ do { \ struct linux_binprm; #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1 -int arch_setup_additional_pages(struct linux_binprm *, int); +int arch_setup_additional_pages(struct linux_binprm *, unsigned long, int); #endif
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index 6bc9c19..54dad2f 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c@@ -195,7 +195,8 @@ static void vdso_init_cr5(void) * This is called from binfmt_elf, we create the special vma for the * vDSO and insert it into the mm struct tree */ -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) +int arch_setup_additional_pages(struct linux_binprm *bprm, + unsigned long start, int uses_interp) { struct mm_struct *mm = current->mm; struct page **vdso_pagelist;
@@ -226,6 +227,10 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) vdso_pages = vdso32_pages; #endif + /* in case restart(2) mandates a specific location */ + if (start) + vdso_base = start; + /* * vDSO has a problem and was disabled, just don't "enable" it for * the process
@@ -248,6 +253,12 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) goto out_up; } + /* for restart(2), double check that we got we asked for */ + if (start && vdso_base != start) { + rc = -EINVAL; + goto out_up; + } + /* * Put vDSO base into mm struct. We need to do this before calling * install_special_mapping or the perf counter mmap tracking code
diff --git a/arch/sh/include/asm/elf.h b/arch/sh/include/asm/elf.h
index ce830fa..4128c30 100644
--- a/arch/sh/include/asm/elf.h
+++ b/arch/sh/include/asm/elf.h@@ -201,6 +201,7 @@ do { \ #define ARCH_HAS_SETUP_ADDITIONAL_PAGES struct linux_binprm; extern int arch_setup_additional_pages(struct linux_binprm *bprm, + unsigned long start, int uses_interp); extern unsigned int vdso_enabled;
diff --git a/arch/sh/kernel/vsyscall/vsyscall.c b/arch/sh/kernel/vsyscall/vsyscall.c
index 242117c..6dbdfe1 100644
--- a/arch/sh/kernel/vsyscall/vsyscall.c
+++ b/arch/sh/kernel/vsyscall/vsyscall.c@@ -58,7 +58,7 @@ int __init vsyscall_init(void) } /* Setup a VMA at program startup for the vsyscall page */ -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) +int arch_setup_additional_pages(struct linux_binprm *bprm, unsigned long start, int uses_interp) { struct mm_struct *mm = current->mm; unsigned long addr;
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index f2ad216..3761be8 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h@@ -312,9 +312,10 @@ struct linux_binprm; #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1 extern int arch_setup_additional_pages(struct linux_binprm *bprm, + unsigned long start, int uses_interp); -extern int syscall32_setup_pages(struct linux_binprm *, int exstack); +extern int syscall32_setup_pages(struct linux_binprm *, unsigned long start, int exstack); #define compat_arch_setup_additional_pages syscall32_setup_pages extern unsigned long arch_randomize_brk(struct mm_struct *mm);
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 02b442e..62043c1 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c@@ -310,7 +310,8 @@ int __init sysenter_setup(void) } /* Setup a VMA at program startup for the vsyscall page */ -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) +int arch_setup_additional_pages(struct linux_binprm *bprm, + unsigned long start, int uses_interp) { struct mm_struct *mm = current->mm; unsigned long addr;
@@ -331,13 +332,17 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) if (compat) addr = VDSO_HIGH_BASE; else { - addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0); + addr = get_unmapped_area(NULL, start, PAGE_SIZE, 0, 0); if (IS_ERR_VALUE(addr)) { ret = addr; goto up_fail; } } + /* for restart(2), double check that we got we asked for */ + if (start && addr != start) + goto up_fail; + current->mm->context.vdso = (void *)addr; if (compat_uses_vma || !compat) {
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index ac74869..b813286 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c@@ -100,23 +100,28 @@ static unsigned long vdso_addr(unsigned long start, unsigned len) /* Setup a VMA at program startup for the vsyscall page. Not called for compat tasks */ -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) +int arch_setup_additional_pages(struct linux_binprm *bprm, + unsigned long start, int uses_interp) { struct mm_struct *mm = current->mm; unsigned long addr; - int ret; + int ret = -EINVAL; if (!vdso_enabled) return 0; down_write(&mm->mmap_sem); - addr = vdso_addr(mm->start_stack, vdso_size); + addr = start ? : vdso_addr(mm->start_stack, vdso_size); addr = get_unmapped_area(NULL, addr, vdso_size, 0, 0); if (IS_ERR_VALUE(addr)) { ret = addr; goto up_fail; } + /* for restart(2), double check that we got we asked for */ + if (start && addr != start) + goto up_fail; + current->mm->context.vdso = (void *)addr; ret = install_special_mapping(mm, addr, vdso_size,
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 535e763..6434003 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c@@ -923,7 +923,7 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) set_binfmt(&elf_format); #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES - retval = arch_setup_additional_pages(bprm, !!elf_interpreter); + retval = arch_setup_additional_pages(bprm, 0, !!elf_interpreter); if (retval < 0) { send_sig(SIGKILL, current, 0); goto out;
--
1.6.3.3