[PATCH V5 09/30] csky: VDSO and rt_sigreturn

Guo Ren
2018-09-24T14:38:20Z

This patch adds files related to VDSO and our VDSO only support
rt_sigreturn.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
---
arch/csky/abiv1/inc/abi/vdso.h | 18 +++++++++
arch/csky/abiv2/inc/abi/vdso.h | 24 ++++++++++++
arch/csky/include/asm/vdso.h | 13 +++++++
arch/csky/kernel/vdso.c | 85 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 140 insertions(+)
create mode 100644 arch/csky/abiv1/inc/abi/vdso.h
create mode 100644 arch/csky/abiv2/inc/abi/vdso.h
create mode 100644 arch/csky/include/asm/vdso.h
create mode 100644 arch/csky/kernel/vdso.c

diff --git a/arch/csky/abiv1/inc/abi/vdso.h b/arch/csky/abiv1/inc/abi/vdso.h
new file mode 100644
index 0000000..7b3dbde
--- /dev/null
+++ b/arch/csky/abiv1/inc/abi/vdso.h
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/uaccess.h>
+
+static inline int setup_vdso_page(unsigned short *ptr)
+{
+ int err = 0;
+
+ /* movi r1, 127 */
+ err |= __put_user(0x67f1, ptr + 0);
+ /* addi r1, (139 - 127) */
+ err |= __put_user(0x20b1, ptr + 1);
+ /* trap 0 */
+ err |= __put_user(0x0008, ptr + 2);
+
+ return err;
+}
diff --git a/arch/csky/abiv2/inc/abi/vdso.h b/arch/csky/abiv2/inc/abi/vdso.h
new file mode 100644
index 0000000..2b5f43b
--- /dev/null
+++ b/arch/csky/abiv2/inc/abi/vdso.h
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ABI_CSKY_VDSO_H
+#define __ABI_CSKY_VDSO_H
+
+#include <linux/uaccess.h>
+
+static inline int setup_vdso_page(unsigned short *ptr)
+{
+ int err = 0;
+
+ /* movi r7, 173 */
+ err |= __put_user(0xea07, ptr);
+ err |= __put_user(0x008b, ptr+1);
+
+ /* trap 0 */
+ err |= __put_user(0xc000, ptr+2);
+ err |= __put_user(0x2020, ptr+3);
+
+ return err;
+}
+
+#endif /* __ABI_CSKY_STRING_H */
diff --git a/arch/csky/include/asm/vdso.h b/arch/csky/include/asm/vdso.h
new file mode 100644
index 0000000..0345b0d
--- /dev/null
+++ b/arch/csky/include/asm/vdso.h
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_VDSO_H
+#define __ASM_CSKY_VDSO_H
+
+#include <abi/vdso.h>
+
+struct csky_vdso {
+ unsigned short rt_signal_retcode[4];
+};
+
+#endif /* __ASM_CSKY_VDSO_H */
diff --git a/arch/csky/kernel/vdso.c b/arch/csky/kernel/vdso.c
new file mode 100644
index 0000000..55ed68b
--- /dev/null
+++ b/arch/csky/kernel/vdso.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/binfmts.h>
+#include <linux/elf.h>
+#include <linux/vmalloc.h>
+#include <linux/unistd.h>
+#include <linux/uaccess.h>
+
+#include <asm/vdso.h>
+#include <asm/cacheflush.h>
+
+static struct page *vdso_page;
+
+static int __init init_vdso(void)
+{
+ struct csky_vdso *vdso;
+ int err = 0;
+
+ vdso_page = alloc_page(GFP_KERNEL);
+ if (!vdso_page)
+ panic("Cannot allocate vdso");
+
+ vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL);
+ if (!vdso)
+ panic("Cannot map vdso");
+
+ clear_page(vdso);
+
+ err = setup_vdso_page(vdso->rt_signal_retcode);
+ if (err) panic("Cannot set signal return code, err: %x.", err);
+
+ dcache_wb_range((unsigned long)vdso, (unsigned long)vdso + 16);
+
+ vunmap(vdso);
+
+ return 0;
+}
+subsys_initcall(init_vdso);
+
+int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
+{
+ int ret;
+ unsigned long addr;
+ struct mm_struct *mm = current->mm;
+
+ down_write(&mm->mmap_sem);
+
+ addr = get_unmapped_area(NULL, STACK_TOP, PAGE_SIZE, 0, 0);
+ if (IS_ERR_VALUE(addr)) {
+ ret = addr;
+ goto up_fail;
+ }
+
+ ret = install_special_mapping(
+ mm,
+ addr,
+ PAGE_SIZE,
+ VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
+ &vdso_page);
+ if (ret)
+ goto up_fail;
+
+ mm->context.vdso = (void *)addr;
+
+up_fail:
+ up_write(&mm->mmap_sem);
+ return ret;
+}
+
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+ if (vma->vm_mm == NULL)
+ return NULL;
+
+ if (vma->vm_start == (long)vma->vm_mm->context.vdso)
+ return "[vdso]";
+ else
+ return NULL;
+}
--
2.7.4