diff options
Diffstat (limited to 'arch/sh/kernel/vsyscall')
| -rw-r--r-- | arch/sh/kernel/vsyscall/.gitignore | 1 | ||||
| -rw-r--r-- | arch/sh/kernel/vsyscall/Makefile | 9 | ||||
| -rw-r--r-- | arch/sh/kernel/vsyscall/vsyscall.c | 39 |
3 files changed, 39 insertions, 10 deletions
diff --git a/arch/sh/kernel/vsyscall/.gitignore b/arch/sh/kernel/vsyscall/.gitignore index 40836ad9079c..530a3031a88d 100644 --- a/arch/sh/kernel/vsyscall/.gitignore +++ b/arch/sh/kernel/vsyscall/.gitignore @@ -1 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only vsyscall.lds diff --git a/arch/sh/kernel/vsyscall/Makefile b/arch/sh/kernel/vsyscall/Makefile index 6e8664448048..cb4f0bb80c38 100644 --- a/arch/sh/kernel/vsyscall/Makefile +++ b/arch/sh/kernel/vsyscall/Makefile @@ -1,11 +1,10 @@ # SPDX-License-Identifier: GPL-2.0 obj-y += vsyscall.o vsyscall-syscall.o vsyscall-syms.o -$(obj)/vsyscall-syscall.o: \ - $(foreach F,trapa,$(obj)/vsyscall-$F.so) +$(obj)/vsyscall-syscall.o: $(obj)/vsyscall-trapa.so # Teach kbuild about targets -targets += $(foreach F,trapa,vsyscall-$F.o vsyscall-$F.so) +targets += vsyscall-trapa.o vsyscall-traps.so targets += vsyscall-note.o vsyscall.lds vsyscall-dummy.o # The DSO images are built using a special linker script @@ -20,14 +19,14 @@ vsyscall-flags = -shared -s -Wl,-soname=linux-gate.so.1 -Wl,--hash-style=sysv SYSCFLAGS_vsyscall-trapa.so = $(vsyscall-flags) $(obj)/vsyscall-trapa.so: \ -$(obj)/vsyscall-%.so: $(src)/vsyscall.lds $(obj)/vsyscall-%.o FORCE +$(obj)/vsyscall-%.so: $(obj)/vsyscall.lds $(obj)/vsyscall-%.o FORCE $(call if_changed,syscall) # We also create a special relocatable object that should mirror the symbol # table and layout of the linked DSO. With ld -R we can then refer to # these symbols in the kernel code rather than hand-coded addresses. SYSCFLAGS_vsyscall-dummy.o = -r -$(obj)/vsyscall-dummy.o: $(src)/vsyscall.lds \ +$(obj)/vsyscall-dummy.o: $(obj)/vsyscall.lds \ $(obj)/vsyscall-trapa.o $(obj)/vsyscall-note.o FORCE $(call if_changed,syscall) diff --git a/arch/sh/kernel/vsyscall/vsyscall.c b/arch/sh/kernel/vsyscall/vsyscall.c index 98494480f048..1563dcc55fd3 100644 --- a/arch/sh/kernel/vsyscall/vsyscall.c +++ b/arch/sh/kernel/vsyscall/vsyscall.c @@ -14,6 +14,7 @@ #include <linux/module.h> #include <linux/elf.h> #include <linux/sched.h> +#include <linux/sysctl.h> #include <linux/err.h> /* @@ -30,12 +31,28 @@ static int __init vdso_setup(char *s) } __setup("vdso=", vdso_setup); +static const struct ctl_table vdso_table[] = { + { + .procname = "vdso_enabled", + .data = &vdso_enabled, + .maxlen = sizeof(vdso_enabled), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, +}; + /* * These symbols are defined by vsyscall.o to mark the bounds * of the ELF DSO images included therein. */ extern const char vsyscall_trapa_start, vsyscall_trapa_end; static struct page *syscall_pages[1]; +static struct vm_special_mapping vdso_mapping = { + .name = "[vdso]", + .pages = syscall_pages, +}; int __init vsyscall_init(void) { @@ -54,14 +71,23 @@ int __init vsyscall_init(void) return 0; } +static int __init vm_sysctl_init(void) +{ + register_sysctl_init("vm", vdso_table); + return 0; +} + +fs_initcall(vm_sysctl_init); + /* Setup a VMA at program startup for the vsyscall 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; - if (down_write_killable(&mm->mmap_sem)) + if (mmap_write_lock_killable(mm)) return -EINTR; addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0); @@ -70,17 +96,20 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) goto up_fail; } - ret = install_special_mapping(mm, addr, PAGE_SIZE, + vdso_mapping.pages = syscall_pages; + vma = _install_special_mapping(mm, addr, PAGE_SIZE, VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, - syscall_pages); - if (unlikely(ret)) + &vdso_mapping); + ret = PTR_ERR(vma); + if (IS_ERR(vma)) goto up_fail; current->mm->context.vdso = (void *)addr; + ret = 0; up_fail: - up_write(&mm->mmap_sem); + mmap_write_unlock(mm); return ret; } |