[PATCH v10 1/6] ARM: use _install_special_mapping for sigpage
From: Nathan Lynch <hidden>
Date: 2014-09-22 19:18:00
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
_install_special_mapping allows the VMA to be identifed in /proc/pid/maps without the use of arch_vma_name, providing a slight net reduction in object size: text data bss dec hex filename 2996 96 144 3236 ca4 arch/arm/kernel/process.o (before) 2956 104 144 3204 c84 arch/arm/kernel/process.o (after) Signed-off-by: Nathan Lynch <redacted> Reviewed-by: Kees Cook <redacted> --- arch/arm/kernel/process.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 81ef686a91ca..46fbbb3701a0 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c@@ -472,19 +472,23 @@ int in_gate_area_no_mm(unsigned long addr) const char *arch_vma_name(struct vm_area_struct *vma) { - return is_gate_vma(vma) ? "[vectors]" : - (vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ? - "[sigpage]" : NULL; + return is_gate_vma(vma) ? "[vectors]" : NULL; } static struct page *signal_page; extern struct page *get_signal_page(void); +static const struct vm_special_mapping sigpage_mapping = { + .name = "[sigpage]", + .pages = &signal_page, +}; + int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) { struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; unsigned long addr; - int ret; + int ret = 0; if (!signal_page) signal_page = get_signal_page();
@@ -498,12 +502,16 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) goto up_fail; } - ret = install_special_mapping(mm, addr, PAGE_SIZE, + vma = _install_special_mapping(mm, addr, PAGE_SIZE, VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, - &signal_page); + &sigpage_mapping); + + if (IS_ERR(vma)) { + ret = PTR_ERR(vma); + goto up_fail; + } - if (ret == 0) - mm->context.sigpage = addr; + mm->context.sigpage = addr; up_fail: up_write(&mm->mmap_sem);
--
1.9.3