Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx> --- arch/csky/abiv1/inc/abi/vdso.h | 19 +++++++++ arch/csky/abiv2/inc/abi/vdso.h | 18 +++++++++ arch/csky/include/asm/vdso.h | 12 ++++++ arch/csky/kernel/vdso.c | 89 ++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 138 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..029c4e3 --- /dev/null +++ b/arch/csky/abiv1/inc/abi/vdso.h @@ -0,0 +1,19 @@ +// 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; + + /* movi r1, 127 */ + err |= __put_user(0x6000 + (127 << 4)+1, ptr+0); + /* addi r1, 32 */ + err |= __put_user(0x2000 + ((32-1) << 4)+1, ptr+1); + /* addi r1, 173-127-32 */ + err |= __put_user(0x2000 + (((173-127-32) -1)<< 4)+1, ptr+2); + /* trap 0 */ + err |= __put_user(0x08, ptr+3); + + 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..f9da48a --- /dev/null +++ b/arch/csky/abiv2/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; + + /* movi r7, 173 */ + err |= __put_user(0xEA00+7, ptr); + err |= __put_user(173, ptr+1); + + /* trap 0 */ + err |= __put_user(0xC000, ptr+2); + err |= __put_user(0x2020, ptr+3); + + return err; +} diff --git a/arch/csky/include/asm/vdso.h b/arch/csky/include/asm/vdso.h new file mode 100644 index 0000000..b275440 --- /dev/null +++ b/arch/csky/include/asm/vdso.h @@ -0,0 +1,12 @@ +// 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..dd59aae --- /dev/null +++ b/arch/csky/kernel/vdso.c @@ -0,0 +1,89 @@ +// 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); + + /* + * __NR_rt_sigreturn must be 173 + * Because gcc/config/csky/linux-unwind.h use hard code to parse rt_sigframe. + */ + 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