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,
thiago.macieira@intel.com, jing2.liu@intel.com,
ravi.v.shankar@intel.com, linux-kernel@vger.kernel.org,
chang.seok.bae@intel.com
Subject: [PATCH v7 17/26] x86/fpu/xstate: Disable XSTATE support if an inconsistent state is detected
Date: Sat, 10 Jul 2021 06:03:04 -0700 [thread overview]
Message-ID: <20210710130313.5072-18-chang.seok.bae@intel.com> (raw)
In-Reply-To: <20210710130313.5072-1-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 | 40 ++++++++++++++++++++++++------------
1 file changed, 27 insertions(+), 13 deletions(-)
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 353125a18274..eda70bdca45c 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -654,11 +654,11 @@ 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)
@@ -667,7 +667,7 @@ 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.
@@ -695,9 +695,12 @@ 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;
}
/**
@@ -707,13 +710,14 @@ static void check_xstate_against_struct(int nr)
* excluded. Only the size of the buffer for task->fpu is checked here.
*
* @include_dynamic_states: A knob to include dynamic states or not.
+ * @size: A pointer to record the size.
*
- * Return: The calculated xstate size.
+ * Return: 0 if successful; otherwise, error code.
*/
-static unsigned int calculate_xstate_size(bool include_dynamic_states)
+static int calculate_xstate_size(bool include_dynamic_states, unsigned int *size)
{
unsigned int xstate_size = FXSAVE_SIZE + XSAVE_HDR_SIZE;
- int i;
+ int i, err;
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
if (!xfeature_enabled(i))
@@ -722,7 +726,10 @@ static unsigned int calculate_xstate_size(bool include_dynamic_states)
if (!include_dynamic_states && (xfeatures_mask_user_dynamic & BIT_ULL(i)))
continue;
- check_xstate_against_struct(i);
+ err = check_xstate_against_struct(i);
+ if (err)
+ return err;
+
/*
* Supervisor state components can be managed only by
* XSAVES.
@@ -748,7 +755,9 @@ static unsigned int calculate_xstate_size(bool include_dynamic_states)
xstate_size += xfeature_size(i);
}
- return xstate_size;
+ if (size)
+ *size = xstate_size;
+ return 0;
}
@@ -835,6 +844,7 @@ static int __init init_xstate_size(void)
/* Recompute the context size for enabled features: */
unsigned int possible_xstate_size, xstate_size;
unsigned int xsave_size;
+ int err;
xsave_size = get_xsave_size();
@@ -848,7 +858,9 @@ static int __init init_xstate_size(void)
* 'true' to include dynamic states. Cross-check with the CPUID-
* provided size and record it.
*/
- xstate_size = calculate_xstate_size(true);
+ err = calculate_xstate_size(true, &xstate_size);
+ if (err)
+ return err;
XSTATE_WARN_ON(possible_xstate_size != xstate_size);
set_xstate_config(XSTATE_MAX_SIZE, possible_xstate_size);
@@ -857,7 +869,9 @@ static int __init init_xstate_size(void)
* 'false' to exclude dynamic states. Ensure the size fits in
* the statically-allocated buffer and record it.
*/
- xstate_size = calculate_xstate_size(false);
+ err = calculate_xstate_size(false, &xstate_size);
+ if (err)
+ return err;
if (!is_supported_xstate_size(xstate_size))
return -EINVAL;
set_xstate_config(XSTATE_MIN_SIZE, xstate_size);
--
2.17.1
next prev parent reply other threads:[~2021-07-10 13:10 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-10 13:02 [PATCH v7 00/26] x86: Support Intel Advanced Matrix Extensions Chang S. Bae
2021-07-10 13:02 ` [PATCH v7 01/26] x86/fpu/xstate: Modify the initialization helper to handle both static and dynamic buffers Chang S. Bae
2021-07-10 13:02 ` [PATCH v7 02/26] x86/fpu/xstate: Modify state copy helpers " Chang S. Bae
2021-07-10 13:02 ` [PATCH v7 03/26] x86/fpu/xstate: Modify address finders " Chang S. Bae
2021-07-10 13:02 ` [PATCH v7 04/26] x86/fpu/xstate: Add a new variable to indicate dynamic user states Chang S. Bae
2021-07-10 13:02 ` [PATCH v7 05/26] x86/fpu/xstate: Add new variables to indicate dynamic XSTATE buffer size Chang S. Bae
2021-07-10 13:02 ` [PATCH v7 06/26] x86/fpu/xstate: Calculate and remember dynamic XSTATE buffer sizes Chang S. Bae
2021-07-10 13:02 ` [PATCH v7 07/26] x86/fpu/xstate: Convert the struct fpu 'state' field to a pointer Chang S. Bae
2021-07-10 13:02 ` [PATCH v7 08/26] x86/fpu/xstate: Introduce helpers to manage the XSTATE buffer dynamically Chang S. Bae
2021-07-10 13:02 ` [PATCH v7 09/26] x86/fpu/xstate: Update the XSTATE save function to support dynamic states Chang S. Bae
2021-07-10 13:02 ` [PATCH v7 10/26] x86/fpu/xstate: Update the XSTATE buffer address finder " Chang S. Bae
2021-07-10 13:02 ` [PATCH v7 11/26] x86/fpu/xstate: Update the XSTATE context copy function " Chang S. Bae
2021-07-10 13:02 ` [PATCH v7 12/26] x86/fpu/xstate: Use feature disable (XFD) to protect dynamic user state Chang S. Bae
2021-07-13 19:13 ` Thiago Macieira
2021-07-17 15:47 ` Bae, Chang Seok
2021-07-10 13:03 ` [PATCH v7 13/26] x86/fpu/xstate: Support ptracer-induced XSTATE buffer expansion Chang S. Bae
2021-07-10 13:03 ` [PATCH v7 14/26] x86/arch_prctl: Create ARCH_SET_XSTATE_ENABLE/ARCH_GET_XSTATE_ENABLE Chang S. Bae
2021-07-10 13:03 ` [PATCH v7 15/26] x86/fpu/xstate: Support both legacy and expanded signal XSTATE size Chang S. Bae
2021-07-10 13:03 ` [PATCH v7 16/26] x86/fpu/xstate: Adjust the XSAVE feature table to address gaps in state component numbers Chang S. Bae
2021-07-10 13:03 ` Chang S. Bae [this message]
2021-07-10 13:03 ` [PATCH v7 18/26] x86/cpufeatures/amx: Enumerate Advanced Matrix Extension (AMX) feature bits Chang S. Bae
2021-07-10 13:03 ` [PATCH v7 19/26] x86/fpu/amx: Define AMX state components and have it used for boot-time checks Chang S. Bae
2021-07-10 13:03 ` [PATCH v7 20/26] x86/fpu/amx: Initialize child's AMX state Chang S. Bae
2021-07-10 13:03 ` [PATCH v7 21/26] x86/fpu/amx: Enable the AMX feature in 64-bit mode Chang S. Bae
2021-07-10 13:03 ` [PATCH v7 22/26] x86/fpu/xstate: Skip writing zeros to signal frame for dynamic user states if in INIT-state Chang S. Bae
2021-07-10 13:03 ` [PATCH v7 23/26] selftest/x86/amx: Test cases for the AMX state management Chang S. Bae
2021-07-10 13:03 ` [PATCH v7 24/26] x86/insn/amx: Add TILERELEASE instruction to the opcode map Chang S. Bae
2021-07-10 13:03 ` [PATCH v7 25/26] intel_idle/amx: Add SPR support with XTILEDATA capability Chang S. Bae
2021-07-16 17:34 ` Rafael J. Wysocki
2021-07-16 17:37 ` Bae, Chang Seok
2021-07-10 13:03 ` [PATCH v7 26/26] x86/fpu/xstate: Add a sanity check for XFD state when saving XSTATE Chang S. Bae
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