Unverified Commit 5155cf7b authored by Palmer Dabbelt's avatar Palmer Dabbelt
Browse files

Merge remote-tracking branch 'palmer/riscv-vdso-cleanup' into fixes 

This contains a VDSO cleanup, along with a handful of VDSO fixes.

* palmer/riscv-vdso-cleanup:
  riscv/vdso: make arch_setup_additional_pages wait for mmap_sem for write killable
  riscv/vdso: Move vdso data page up front
  riscv/vdso: Refactor asm/vdso.h
parents 6880fa6c 8bb0ab3a

arch/riscv/include/asm/syscall.h

+1 −0
Original line number Diff line number Diff line
@@ -82,4 +82,5 @@ static inline int syscall_get_arch(struct task_struct *task) 
#endif

}



asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);

#endif	/* _ASM_RISCV_SYSCALL_H */

arch/riscv/include/asm/vdso.h

+12 −6
Original line number Diff line number Diff line
@@ -16,18 +16,24 @@ 
#ifdef CONFIG_MMU



#include <linux/types.h>

#include <generated/vdso-offsets.h>

/*

 * All systems with an MMU have a VDSO, but systems without an MMU don't

 * support shared libraries and therefor don't have one.

 */

#ifdef CONFIG_MMU



#define __VVAR_PAGES    1



#ifndef CONFIG_GENERIC_TIME_VSYSCALL

struct vdso_data {

};

#endif

#ifndef __ASSEMBLY__

#include <generated/vdso-offsets.h>



#define VDSO_SYMBOL(base, name)							\

	(void __user *)((unsigned long)(base) + __vdso_##name##_offset)



#endif /* CONFIG_MMU */



asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);

#endif /* !__ASSEMBLY__ */



#endif /* CONFIG_MMU */



#endif /* _ASM_RISCV_VDSO_H */

arch/riscv/kernel/syscall_table.c

+0 −1
Original line number Diff line number Diff line
@@ -7,7 +7,6 @@ 
#include <linux/linkage.h>

#include <linux/syscalls.h>

#include <asm-generic/syscalls.h>

#include <asm/vdso.h>

#include <asm/syscall.h>



#undef __SYSCALL

arch/riscv/kernel/vdso.c

+33 −20
Original line number Diff line number Diff line
@@ -12,14 +12,24 @@ 
#include <linux/binfmts.h>

#include <linux/err.h>

#include <asm/page.h>

#include <asm/vdso.h>



#ifdef CONFIG_GENERIC_TIME_VSYSCALL

#include <vdso/datapage.h>

#else

#include <asm/vdso.h>

struct vdso_data {

};

#endif



extern char vdso_start[], vdso_end[];



enum vvar_pages {

	VVAR_DATA_PAGE_OFFSET,

	VVAR_NR_PAGES,

};



#define VVAR_SIZE  (VVAR_NR_PAGES << PAGE_SHIFT)



static unsigned int vdso_pages __ro_after_init;

static struct page **vdso_pagelist __ro_after_init;
@@ -38,7 +48,7 @@ static int __init vdso_init(void) 


	vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT;

	vdso_pagelist =

		kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL);

		kcalloc(vdso_pages + VVAR_NR_PAGES, sizeof(struct page *), GFP_KERNEL);

	if (unlikely(vdso_pagelist == NULL)) {

		pr_err("vdso: pagelist allocation failed\n");

		return -ENOMEM;
@@ -63,38 +73,41 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, 
	unsigned long vdso_base, vdso_len;

	int ret;



	vdso_len = (vdso_pages + 1) << PAGE_SHIFT;

	BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES);



	vdso_len = (vdso_pages + VVAR_NR_PAGES) << PAGE_SHIFT;



	if (mmap_write_lock_killable(mm))

		return -EINTR;



	mmap_write_lock(mm);

	vdso_base = get_unmapped_area(NULL, 0, vdso_len, 0, 0);

	if (IS_ERR_VALUE(vdso_base)) {

		ret = vdso_base;

		goto end;

	}



	/*

	 * Put vDSO base into mm struct. We need to do this before calling

	 * install_special_mapping or the perf counter mmap tracking code

	 * will fail to recognise it as a vDSO (since arch_vma_name fails).

	 */

	mm->context.vdso = (void *)vdso_base;

	mm->context.vdso = NULL;

	ret = install_special_mapping(mm, vdso_base, VVAR_SIZE,

		(VM_READ | VM_MAYREAD), &vdso_pagelist[vdso_pages]);

	if (unlikely(ret))

		goto end;



	ret =

	   install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,

	   install_special_mapping(mm, vdso_base + VVAR_SIZE,

		vdso_pages << PAGE_SHIFT,

		(VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC),

		vdso_pagelist);



	if (unlikely(ret)) {

		mm->context.vdso = NULL;

	if (unlikely(ret))

		goto end;

	}



	vdso_base += (vdso_pages << PAGE_SHIFT);

	ret = install_special_mapping(mm, vdso_base, PAGE_SIZE,

		(VM_READ | VM_MAYREAD), &vdso_pagelist[vdso_pages]);

	/*

	 * Put vDSO base into mm struct. We need to do this before calling

	 * install_special_mapping or the perf counter mmap tracking code

	 * will fail to recognise it as a vDSO (since arch_vma_name fails).

	 */

	mm->context.vdso = (void *)vdso_base + VVAR_SIZE;



	if (unlikely(ret))

		mm->context.vdso = NULL;

end:

	mmap_write_unlock(mm);

	return ret;
@@ -105,7 +118,7 @@ const char *arch_vma_name(struct vm_area_struct *vma) 
	if (vma->vm_mm && (vma->vm_start == (long)vma->vm_mm->context.vdso))

		return "[vdso]";

	if (vma->vm_mm && (vma->vm_start ==

			   (long)vma->vm_mm->context.vdso + PAGE_SIZE))

			   (long)vma->vm_mm->context.vdso - VVAR_SIZE))

		return "[vdso_data]";

	return NULL;

}

arch/riscv/kernel/vdso/vdso.lds.S

+2 −1
Original line number Diff line number Diff line
@@ -3,12 +3,13 @@ 
 * Copyright (C) 2012 Regents of the University of California

 */

#include <asm/page.h>

#include <asm/vdso.h>



OUTPUT_ARCH(riscv)



SECTIONS

{

	PROVIDE(_vdso_data = . + PAGE_SIZE);

	PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE);

	. = SIZEOF_HEADERS;



	.hash		: { *(.hash) }			:text