linux/arch/x86/include/asm/mpx.h
Dave Hansen 613fcb7d3c x86/mpx: Support 32-bit binaries on 64-bit kernels
Right now, the kernel can only switch between 64-bit and 32-bit
binaries at compile time. This patch adds support for 32-bit
binaries on 64-bit kernels when we support ia32 emulation.

We essentially choose which set of table sizes to use when doing
arithmetic for the bounds table calculations.

This also uses a different approach for calculating the table
indexes than before.  I think the new one makes it much more
clear what is going on, and allows us to share more code between
the 32-bit and 64-bit cases.

Based-on-patch-by: Qiaowei Ren <qiaowei.ren@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150607183705.E01F21E2@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-09 12:24:34 +02:00

98 lines
2.7 KiB
C

#ifndef _ASM_X86_MPX_H
#define _ASM_X86_MPX_H
#include <linux/types.h>
#include <asm/ptrace.h>
#include <asm/insn.h>
/*
* NULL is theoretically a valid place to put the bounds
* directory, so point this at an invalid address.
*/
#define MPX_INVALID_BOUNDS_DIR ((void __user *)-1)
#define MPX_BNDCFG_ENABLE_FLAG 0x1
#define MPX_BD_ENTRY_VALID_FLAG 0x1
/*
* The upper 28 bits [47:20] of the virtual address in 64-bit
* are used to index into bounds directory (BD).
*
* The directory is 2G (2^31) in size, and with 8-byte entries
* it has 2^28 entries.
*/
#define MPX_BD_SIZE_BYTES_64 (1UL<<31)
#define MPX_BD_ENTRY_BYTES_64 8
#define MPX_BD_NR_ENTRIES_64 (MPX_BD_SIZE_BYTES_64/MPX_BD_ENTRY_BYTES_64)
/*
* The 32-bit directory is 4MB (2^22) in size, and with 4-byte
* entries it has 2^20 entries.
*/
#define MPX_BD_SIZE_BYTES_32 (1UL<<22)
#define MPX_BD_ENTRY_BYTES_32 4
#define MPX_BD_NR_ENTRIES_32 (MPX_BD_SIZE_BYTES_32/MPX_BD_ENTRY_BYTES_32)
/*
* A 64-bit table is 4MB total in size, and an entry is
* 4 64-bit pointers in size.
*/
#define MPX_BT_SIZE_BYTES_64 (1UL<<22)
#define MPX_BT_ENTRY_BYTES_64 32
#define MPX_BT_NR_ENTRIES_64 (MPX_BT_SIZE_BYTES_64/MPX_BT_ENTRY_BYTES_64)
/*
* A 32-bit table is 16kB total in size, and an entry is
* 4 32-bit pointers in size.
*/
#define MPX_BT_SIZE_BYTES_32 (1UL<<14)
#define MPX_BT_ENTRY_BYTES_32 16
#define MPX_BT_NR_ENTRIES_32 (MPX_BT_SIZE_BYTES_32/MPX_BT_ENTRY_BYTES_32)
#define MPX_BNDSTA_TAIL 2
#define MPX_BNDCFG_TAIL 12
#define MPX_BNDSTA_ADDR_MASK (~((1UL<<MPX_BNDSTA_TAIL)-1))
#define MPX_BNDCFG_ADDR_MASK (~((1UL<<MPX_BNDCFG_TAIL)-1))
#define MPX_BNDSTA_ERROR_CODE 0x3
#ifdef CONFIG_X86_INTEL_MPX
siginfo_t *mpx_generate_siginfo(struct pt_regs *regs);
int mpx_handle_bd_fault(void);
static inline int kernel_managing_mpx_tables(struct mm_struct *mm)
{
return (mm->bd_addr != MPX_INVALID_BOUNDS_DIR);
}
static inline void mpx_mm_init(struct mm_struct *mm)
{
/*
* NULL is theoretically a valid place to put the bounds
* directory, so point this at an invalid address.
*/
mm->bd_addr = MPX_INVALID_BOUNDS_DIR;
}
void mpx_notify_unmap(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long start, unsigned long end);
#else
static inline siginfo_t *mpx_generate_siginfo(struct pt_regs *regs)
{
return NULL;
}
static inline int mpx_handle_bd_fault(void)
{
return -EINVAL;
}
static inline int kernel_managing_mpx_tables(struct mm_struct *mm)
{
return 0;
}
static inline void mpx_mm_init(struct mm_struct *mm)
{
}
static inline void mpx_notify_unmap(struct mm_struct *mm,
struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
}
#endif /* CONFIG_X86_INTEL_MPX */
#endif /* _ASM_X86_MPX_H */