e63e5d5c15
Move validation of user-supplied xstate_header into a helper function, in preparation of calling it from both the ptrace and sigreturn syscall paths. The new function also considers it to be an error if *any* reserved bits are set, whereas before we were just clearing most of them silently. This should reduce the chance of bugs that fail to correctly validate user-supplied XSAVE areas. It also will expose any broken userspace programs that set the other reserved bits; this is desirable because such programs will lose compatibility with future CPUs and kernels if those bits are ever used for anything. (There shouldn't be any such programs, and in fact in the case where the compacted format is in use we were already validating xfeatures. But you never know...) Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-2-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
60 lines
1.8 KiB
C
60 lines
1.8 KiB
C
#ifndef __ASM_X86_XSAVE_H
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#define __ASM_X86_XSAVE_H
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#include <linux/types.h>
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#include <asm/processor.h>
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#include <linux/uaccess.h>
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/* Bit 63 of XCR0 is reserved for future expansion */
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#define XFEATURE_MASK_EXTEND (~(XFEATURE_MASK_FPSSE | (1ULL << 63)))
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#define XSTATE_CPUID 0x0000000d
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#define FXSAVE_SIZE 512
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#define XSAVE_HDR_SIZE 64
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#define XSAVE_HDR_OFFSET FXSAVE_SIZE
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#define XSAVE_YMM_SIZE 256
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#define XSAVE_YMM_OFFSET (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET)
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/* Supervisor features */
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#define XFEATURE_MASK_SUPERVISOR (XFEATURE_MASK_PT)
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/* All currently supported features */
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#define XCNTXT_MASK (XFEATURE_MASK_FP | \
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XFEATURE_MASK_SSE | \
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XFEATURE_MASK_YMM | \
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XFEATURE_MASK_OPMASK | \
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XFEATURE_MASK_ZMM_Hi256 | \
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XFEATURE_MASK_Hi16_ZMM | \
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XFEATURE_MASK_PKRU | \
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XFEATURE_MASK_BNDREGS | \
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XFEATURE_MASK_BNDCSR)
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#ifdef CONFIG_X86_64
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#define REX_PREFIX "0x48, "
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#else
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#define REX_PREFIX
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#endif
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extern u64 xfeatures_mask;
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extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
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extern void __init update_regset_xstate_info(unsigned int size,
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u64 xstate_mask);
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void fpu__xstate_clear_all_cpu_caps(void);
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void *get_xsave_addr(struct xregs_state *xsave, int xstate);
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const void *get_xsave_field_ptr(int xstate_field);
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int using_compacted_format(void);
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int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int offset, unsigned int size);
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int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int offset, unsigned int size);
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int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf);
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int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf);
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/* Validate an xstate header supplied by userspace (ptrace or sigreturn) */
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extern int validate_xstate_header(const struct xstate_header *hdr);
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#endif
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