From: "Chang S. Bae" <chang.seok.bae@intel.com>
To: bp@suse.de, luto@kernel.org, tglx@linutronix.de,
mingo@kernel.org, x86@kernel.org
Cc: len.brown@intel.com, dave.hansen@intel.com, jing2.liu@intel.com,
ravi.v.shankar@intel.com, linux-kernel@vger.kernel.org,
chang.seok.bae@intel.com
Subject: [PATCH v5 18/28] x86/fpu/xstate: Disable xstate support if an inconsistent state is detected
Date: Sun, 23 May 2021 12:32:49 -0700 [thread overview]
Message-ID: <20210523193259.26200-19-chang.seok.bae@intel.com> (raw)
In-Reply-To: <20210523193259.26200-1-chang.seok.bae@intel.com>
The kernel has a sanity check between two methods to calculate xstate size.
In the unlikely event that they disagree, disable the use of xstate.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
---
Changes from v4:
* Added as a new patch. (Thomas Gleixner)
---
arch/x86/kernel/fpu/xstate.c | 33 ++++++++++++++++++++++-----------
1 file changed, 22 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 1cf5888210aa..544e35a9d777 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -730,11 +730,11 @@ 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)) { \
+ if ((nr == nr_macro) && (sz != sizeof(__struct))) { \
+ pr_err("%s: struct is %zu bytes, cpu state %d bytes\n", \
+ __stringify(nr_macro), sizeof(__struct), sz); \
__xstate_dump_leaves(); \
+ return -EINVAL; \
} \
} while (0)
@@ -743,7 +743,7 @@ static void __xstate_dump_leaves(void)
* that our software representation matches what the CPU
* tells us about the state's size.
*/
-static void check_xstate_against_struct(int nr)
+static int check_xstate_against_struct(int nr)
{
/*
* Ask the CPU for the size of the state.
@@ -771,9 +771,12 @@ static void check_xstate_against_struct(int nr)
(nr >= XFEATURE_MAX) ||
(nr == XFEATURE_PT_UNIMPLEMENTED_SO_FAR) ||
((nr >= XFEATURE_RSRVD_COMP_11) && (nr <= XFEATURE_LBR))) {
- WARN_ONCE(1, "no structure for xstate: %d\n", nr);
+ pr_err("no structure for xstate: %d\n", nr);
XSTATE_WARN_ON(1);
+ return -EINVAL;
}
+
+ return 0;
}
/**
@@ -786,9 +789,9 @@ static void check_xstate_against_struct(int nr)
*
* Dynamic supervisor XSAVE features allocate their own buffers and are not covered by these checks.
*
- * Return: nothing.
+ * Returns 0 on success, -EINVAL on state size mismatch.
*/
-static void calculate_xstate_sizes(void)
+static int calculate_xstate_sizes(void)
{
int paranoid_min_size = FXSAVE_SIZE + XSAVE_HDR_SIZE;
int paranoid_max_size = FXSAVE_SIZE + XSAVE_HDR_SIZE;
@@ -796,13 +799,17 @@ static void calculate_xstate_sizes(void)
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
bool user_dynamic;
+ int err;
if (!xfeature_enabled(i))
continue;
user_dynamic = (xfeatures_mask_user_dynamic & BIT_ULL(i)) ? true : false;
- check_xstate_against_struct(i);
+ err = check_xstate_against_struct(i);
+ if (err)
+ return err;
+
/*
* Supervisor state components can be managed only by
* XSAVES, which is compacted-format only.
@@ -837,6 +844,7 @@ static void calculate_xstate_sizes(void)
}
XSTATE_WARN_ON(paranoid_max_size != get_xstate_config(XSTATE_MAX_SIZE));
set_xstate_config(XSTATE_MIN_SIZE, paranoid_min_size);
+ return 0;
}
@@ -923,6 +931,7 @@ static int __init init_xstate_size(void)
/* Recompute the context size for enabled features: */
unsigned int possible_xstate_size;
unsigned int xsave_size;
+ int err;
xsave_size = get_xsave_size();
@@ -939,9 +948,11 @@ static int __init init_xstate_size(void)
/*
* Calculate and double-check the maximum size. Calculate and record
- * the minimum size.
+ * the minimum size. Emit the error when received.
*/
- calculate_xstate_sizes();
+ err = calculate_xstate_sizes();
+ if (err)
+ return err;
/* Ensure the minimum size fits in the statically-alocated buffer: */
if (!is_supported_xstate_size(get_xstate_config(XSTATE_MIN_SIZE)))
--
2.17.1
next prev parent reply other threads:[~2021-05-23 19:39 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-23 19:32 [PATCH v5 00/28] x86: Support Intel Advanced Matrix Extensions Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 01/28] x86/fpu/xstate: Modify the initialization helper to handle both static and dynamic buffers Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 02/28] x86/fpu/xstate: Modify state copy helpers " Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 03/28] x86/fpu/xstate: Modify address finders " Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 04/28] x86/fpu/xstate: Modify the context restore helper " Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 05/28] x86/fpu/xstate: Add a new variable to indicate dynamic user states Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 06/28] x86/fpu/xstate: Add new variables to indicate dynamic xstate buffer size Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 07/28] x86/fpu/xstate: Calculate and remember dynamic xstate buffer sizes Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 08/28] x86/fpu/xstate: Convert the struct fpu 'state' field to a pointer Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 09/28] x86/fpu/xstate: Introduce helpers to manage the xstate buffer dynamically Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 10/28] x86/fpu/xstate: Define the scope of the initial xstate data Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 11/28] x86/fpu/xstate: Update the xstate save function to support dynamic states Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 12/28] x86/fpu/xstate: Update the xstate buffer address finder " Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 13/28] x86/fpu/xstate: Update the xstate context copy function " Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 14/28] x86/fpu/xstate: Prevent unauthorised use of dynamic user state Chang S. Bae
2021-06-16 16:17 ` Dave Hansen
2021-06-16 16:27 ` Dave Hansen
2021-06-16 18:12 ` Andy Lutomirski
2021-06-16 18:47 ` Bae, Chang Seok
2021-06-16 19:01 ` Dave Hansen
2021-06-16 19:23 ` Bae, Chang Seok
2021-06-16 19:28 ` Dave Hansen
2021-06-16 19:37 ` Bae, Chang Seok
2021-06-28 10:11 ` Liu, Jing2
2021-06-29 17:43 ` Bae, Chang Seok
2021-06-29 17:54 ` Dave Hansen
2021-06-29 18:35 ` Bae, Chang Seok
2021-06-29 18:50 ` Dave Hansen
2021-06-29 19:13 ` Bae, Chang Seok
2021-06-29 19:26 ` Dave Hansen
2021-05-23 19:32 ` [PATCH v5 15/28] x86/arch_prctl: Create ARCH_GET_XSTATE/ARCH_PUT_XSTATE Chang S. Bae
2021-05-24 23:10 ` Len Brown
2021-05-25 17:27 ` Borislav Petkov
2021-05-25 17:33 ` Dave Hansen
2021-05-26 0:38 ` Len Brown
2021-05-27 11:14 ` second, sync-alloc syscall Borislav Petkov
2021-05-27 13:59 ` Len Brown
2021-05-27 19:35 ` Andy Lutomirski
2021-05-25 15:46 ` [PATCH v5 15/28] x86/arch_prctl: Create ARCH_GET_XSTATE/ARCH_PUT_XSTATE Dave Hansen
2021-05-23 19:32 ` [PATCH v5 16/28] x86/fpu/xstate: Support ptracer-induced xstate buffer expansion Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 17/28] x86/fpu/xstate: Adjust the XSAVE feature table to address gaps in state component numbers Chang S. Bae
2021-05-23 19:32 ` Chang S. Bae [this message]
2021-05-23 19:32 ` [PATCH v5 19/28] x86/cpufeatures/amx: Enumerate Advanced Matrix Extension (AMX) feature bits Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 20/28] x86/fpu/amx: Define AMX state components and have it used for boot-time checks Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 21/28] x86/fpu/amx: Initialize child's AMX state Chang S. Bae
2021-05-24 3:09 ` Andy Lutomirski
2021-05-24 17:37 ` Len Brown
2021-05-24 18:13 ` Andy Lutomirski
2021-05-24 18:21 ` Len Brown
2021-05-25 3:44 ` Andy Lutomirski
2021-05-23 19:32 ` [PATCH v5 22/28] x86/fpu/amx: Enable the AMX feature in 64-bit mode Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 23/28] selftest/x86/amx: Test cases for the AMX state management Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 24/28] x86/fpu/xstate: Use per-task xstate mask for saving xstate in signal frame Chang S. Bae
2021-05-24 3:15 ` Andy Lutomirski
2021-05-24 18:06 ` Len Brown
2021-05-25 4:47 ` Andy Lutomirski
2021-05-25 14:04 ` Len Brown
2021-05-23 19:32 ` [PATCH v5 25/28] x86/fpu/xstate: Skip writing zeros to signal frame for dynamic user states if in INIT-state Chang S. Bae
2021-05-24 3:25 ` Andy Lutomirski
2021-05-24 18:15 ` Len Brown
2021-05-24 18:29 ` Dave Hansen
2021-05-25 4:46 ` Andy Lutomirski
2021-05-23 19:32 ` [PATCH v5 26/28] selftest/x86/amx: Test case for AMX state copy optimization in signal delivery Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 27/28] x86/insn/amx: Add TILERELEASE instruction to the opcode map Chang S. Bae
2021-05-23 19:32 ` [PATCH v5 28/28] x86/fpu/amx: Clear the AMX state when appropriate Chang S. Bae
2021-05-24 3:13 ` Andy Lutomirski
2021-05-24 14:10 ` Dave Hansen
2021-05-24 17:32 ` Len Brown
2021-05-24 17:39 ` Dave Hansen
2021-05-24 18:24 ` Len Brown
2021-05-27 11:56 ` Peter Zijlstra
2021-05-27 14:02 ` Len Brown
2021-05-24 14:06 ` Dave Hansen
2021-05-24 17:34 ` Len Brown
2021-05-24 21:11 ` [PATCH v5-fix " Chang S. Bae
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