From: tip-bot for Dave Hansen <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, luto@amacapital.net,
torvalds@linux-foundation.org, mingo@kernel.org,
tim.c.chen@linux.intel.com, peterz@infradead.org,
dave.hansen@linux.intel.com, hpa@zytor.com, bp@alien8.de,
fenghua.yu@intel.com, brgerst@gmail.com, dvlasenk@redhat.com,
tglx@linutronix.de
Subject: [tip:x86/fpu] x86/fpu: Check CPU-provided sizes against struct declarations
Date: Mon, 14 Sep 2015 05:24:39 -0700 [thread overview]
Message-ID: <tip-ef78f2a4bf84d8db9f36868decca2dc24e02a6af@git.kernel.org> (raw)
In-Reply-To: <20150902233131.A8DB36DA@viggo.jf.intel.com>
Commit-ID: ef78f2a4bf84d8db9f36868decca2dc24e02a6af
Gitweb: http://git.kernel.org/tip/ef78f2a4bf84d8db9f36868decca2dc24e02a6af
Author: Dave Hansen <dave.hansen@linux.intel.com>
AuthorDate: Wed, 2 Sep 2015 16:31:31 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 14 Sep 2015 12:22:02 +0200
x86/fpu: Check CPU-provided sizes against struct declarations
We now have C structures defined for each of the XSAVE state
components that we support. This patch adds checks during our
verification pass to ensure that the CPU-provided data
enumerated in CPUID leaves matches our C structures.
If not, we warn and dump all the XSAVE CPUID leaves.
Note: this *actually* found an inconsistency with the MPX
'bndcsr' state. The hardware pads it out differently from
our C structures. This patch caught it and warned.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: dave@sr71.net
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20150902233131.A8DB36DA@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/fpu/xstate.c | 45 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index a8297f2..6454f27 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -432,6 +432,49 @@ static void __xstate_dump_leaves(void)
} \
} while (0)
+#define XCHECK_SZ(sz, nr, nr_macro, __struct) do { \
+ if ((nr == nr_macro) && \
+ WARN_ONCE(sz != sizeof(__struct), \
+ "%s: struct is %zu bytes, cpu state %d bytes\n", \
+ __stringify(nr_macro), sizeof(__struct), sz)) { \
+ __xstate_dump_leaves(); \
+ } \
+} while (0)
+
+/*
+ * We have a C struct for each 'xstate'. We need to ensure
+ * that our software representation matches what the CPU
+ * tells us about the state's size.
+ */
+static void check_xstate_against_struct(int nr)
+{
+ /*
+ * Ask the CPU for the size of the state.
+ */
+ int sz = xfeature_size(nr);
+ /*
+ * Match each CPU state with the corresponding software
+ * structure.
+ */
+ XCHECK_SZ(sz, nr, XFEATURE_YMM, struct ymmh_struct);
+ XCHECK_SZ(sz, nr, XFEATURE_BNDREGS, struct mpx_bndreg_state);
+ XCHECK_SZ(sz, nr, XFEATURE_BNDCSR, struct mpx_bndcsr_state);
+ XCHECK_SZ(sz, nr, XFEATURE_OPMASK, struct avx_512_opmask_state);
+ XCHECK_SZ(sz, nr, XFEATURE_ZMM_Hi256, struct avx_512_zmm_uppers_state);
+ XCHECK_SZ(sz, nr, XFEATURE_Hi16_ZMM, struct avx_512_hi16_state);
+
+ /*
+ * Make *SURE* to add any feature numbers in below if
+ * there are "holes" in the xsave state component
+ * numbers.
+ */
+ if ((nr < XFEATURE_YMM) ||
+ (nr >= XFEATURE_MAX)) {
+ WARN_ONCE(1, "no structure for xstate: %d\n", nr);
+ XSTATE_WARN_ON(1);
+ }
+}
+
/*
* This essentially double-checks what the cpu told us about
* how large the XSAVE buffer needs to be. We are recalculating
@@ -445,6 +488,8 @@ static void do_extra_xstate_size_checks(void)
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
if (!xfeature_enabled(i))
continue;
+
+ check_xstate_against_struct(i);
/*
* Supervisor state components can be managed only by
* XSAVES, which is compacted-format only.
next prev parent reply other threads:[~2015-09-14 12:25 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-02 23:31 [PATCH 00/15] [v4] x86, fpu: XSAVE cleanups and sanity checks Dave Hansen
2015-09-02 23:31 ` [PATCH 01/15] x86, fpu: print xfeature buffer size in decimal Dave Hansen
2015-09-14 12:19 ` [tip:x86/fpu] x86/fpu: Print " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 02/15] x86, fpu: move XSAVE-disabling code to a helper Dave Hansen
2015-09-14 12:19 ` [tip:x86/fpu] x86/fpu: Move " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 03/15] x86, fpu: remove XSTATE_RESERVE Dave Hansen
2015-09-14 12:20 ` [tip:x86/fpu] x86/fpu: Remove XSTATE_RESERVE tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 04/15] x86, fpu: kill LWP support Dave Hansen
2015-09-14 12:20 ` [tip:x86/fpu] x86/fpu: Remove partial LWP support definitions tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 05/15] x86, fpu: XSAVE macro renames Dave Hansen
2015-09-14 12:21 ` [tip:x86/fpu] x86/fpu: Rename XSAVE macros tip-bot for Dave Hansen
2015-09-23 10:49 ` Borislav Petkov
2015-09-24 7:24 ` [tip:x86/fpu] x86/fpu: Fixup uninitialized feature_name warning tip-bot for Borislav Petkov
2015-09-02 23:31 ` [PATCH 06/15] x86, fpu: rename XFEATURES_NR_MAX Dave Hansen
2015-09-14 12:21 ` [tip:x86/fpu] x86/fpu: Rename XFEATURES_NR_MAX tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 08/15] x86, fpu: remove xfeature_nr Dave Hansen
2015-09-14 12:22 ` [tip:x86/fpu] x86/fpu: Remove 'xfeature_nr' tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 07/15] x86, fpu: rework XSTATE_* macros to remove magic '2' Dave Hansen
2015-09-14 12:21 ` [tip:x86/fpu] x86/fpu: Rework " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 09/15] x86, fpu: add helper xfeature_enabled() instead of test_bit() Dave Hansen
2015-09-14 12:22 ` [tip:x86/fpu] x86/fpu: Add xfeature_enabled() helper " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 10/15] x86, fpu: rework MPX 'xstate' types Dave Hansen
2015-09-14 12:22 ` [tip:x86/fpu] x86/fpu/mpx: Rework " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 12/15] x86, fpu: add C structures for AVX-512 state components Dave Hansen
2015-09-14 12:23 ` [tip:x86/fpu] x86/fpu: Add " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 11/15] x86, fpu: rework YMM definition Dave Hansen
2015-09-14 12:23 ` [tip:x86/fpu] x86/fpu: Rework " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 14/15] x86, fpu: check to ensure increasing-offset xstate offsets Dave Hansen
2015-09-14 12:24 ` [tip:x86/fpu] x86/fpu: Check " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 13/15] x86, fpu: correct and check XSAVE xstate size calculations Dave Hansen
2015-09-14 12:23 ` [tip:x86/fpu] x86/fpu: Correct " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 15/15] x86, fpu: check CPU-provided sizes against struct declarations Dave Hansen
2015-09-14 12:24 ` tip-bot for Dave Hansen [this message]
2015-09-14 10:07 ` [PATCH 00/15] [v4] x86, fpu: XSAVE cleanups and sanity checks Ingo Molnar
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