The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 8c462d56487e3abdbf8a61cedfe7c795a54f4a78
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024110956-ungloved-yelp-6fba@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 8c462d56487e3abdbf8a61cedfe7c795a54f4a78 Mon Sep 17 00:00:00 2001
From: Mark Rutland <mark.rutland(a)arm.com>
Date: Wed, 6 Nov 2024 16:04:48 +0000
Subject: [PATCH] arm64: smccc: Remove broken support for SMCCCv1.3 SVE discard
hint
SMCCCv1.3 added a hint bit which callers can set in an SMCCC function ID
(AKA "FID") to indicate that it is acceptable for the SMCCC
implementation to discard SVE and/or SME state over a specific SMCCC
call. The kernel support for using this hint is broken and SMCCC calls
may clobber the SVE and/or SME state of arbitrary tasks, though FPSIMD
state is unaffected.
The kernel support is intended to use the hint when there is no SVE or
SME state to save, and to do this it checks whether TIF_FOREIGN_FPSTATE
is set or TIF_SVE is clear in assembly code:
| ldr <flags>, [<current_task>, #TSK_TI_FLAGS]
| tbnz <flags>, #TIF_FOREIGN_FPSTATE, 1f // Any live FP state?
| tbnz <flags>, #TIF_SVE, 2f // Does that state include SVE?
|
| 1: orr <fid>, <fid>, ARM_SMCCC_1_3_SVE_HINT
| 2:
| << SMCCC call using FID >>
This is not safe as-is:
(1) SMCCC calls can be made in a preemptible context and preemption can
result in TIF_FOREIGN_FPSTATE being set or cleared at arbitrary
points in time. Thus checking for TIF_FOREIGN_FPSTATE provides no
guarantee.
(2) TIF_FOREIGN_FPSTATE only indicates that the live FP/SVE/SME state in
the CPU does not belong to the current task, and does not indicate
that clobbering this state is acceptable.
When the live CPU state is clobbered it is necessary to update
fpsimd_last_state.st to ensure that a subsequent context switch will
reload FP/SVE/SME state from memory rather than consuming the
clobbered state. This and the SMCCC call itself must happen in a
critical section with preemption disabled to avoid races.
(3) Live SVE/SME state can exist with TIF_SVE clear (e.g. with only
TIF_SME set), and checking TIF_SVE alone is insufficient.
Remove the broken support for the SMCCCv1.3 SVE saving hint. This is
effectively a revert of commits:
* cfa7ff959a78 ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint")
* a7c3acca5380 ("arm64: smccc: Save lr before calling __arm_smccc_sve_check()")
... leaving behind the ARM_SMCCC_VERSION_1_3 and ARM_SMCCC_1_3_SVE_HINT
definitions, since these are simply definitions from the SMCCC
specification, and the latter is used in KVM via ARM_SMCCC_CALL_HINTS.
If we want to bring this back in future, we'll probably want to handle
this logic in C where we can use all the usual FPSIMD/SVE/SME helper
functions, and that'll likely require some rework of the SMCCC code
and/or its callers.
Fixes: cfa7ff959a78 ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint")
Signed-off-by: Mark Rutland <mark.rutland(a)arm.com>
Cc: Ard Biesheuvel <ardb(a)kernel.org>
Cc: Catalin Marinas <catalin.marinas(a)arm.com>
Cc: Marc Zyngier <maz(a)kernel.org>
Cc: Mark Brown <broonie(a)kernel.org>
Cc: Will Deacon <will(a)kernel.org>
Cc: stable(a)vger.kernel.org
Reviewed-by: Mark Brown <broonie(a)kernel.org>
Link: https://lore.kernel.org/r/20241106160448.2712997-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will(a)kernel.org>
diff --git a/arch/arm64/kernel/smccc-call.S b/arch/arm64/kernel/smccc-call.S
index 487381164ff6..2def9d0dd3dd 100644
--- a/arch/arm64/kernel/smccc-call.S
+++ b/arch/arm64/kernel/smccc-call.S
@@ -7,48 +7,19 @@
#include <asm/asm-offsets.h>
#include <asm/assembler.h>
-#include <asm/thread_info.h>
-
-/*
- * If we have SMCCC v1.3 and (as is likely) no SVE state in
- * the registers then set the SMCCC hint bit to say there's no
- * need to preserve it. Do this by directly adjusting the SMCCC
- * function value which is already stored in x0 ready to be called.
- */
-SYM_FUNC_START(__arm_smccc_sve_check)
-
- ldr_l x16, smccc_has_sve_hint
- cbz x16, 2f
-
- get_current_task x16
- ldr x16, [x16, #TSK_TI_FLAGS]
- tbnz x16, #TIF_FOREIGN_FPSTATE, 1f // Any live FP state?
- tbnz x16, #TIF_SVE, 2f // Does that state include SVE?
-
-1: orr x0, x0, ARM_SMCCC_1_3_SVE_HINT
-
-2: ret
-SYM_FUNC_END(__arm_smccc_sve_check)
-EXPORT_SYMBOL(__arm_smccc_sve_check)
.macro SMCCC instr
- stp x29, x30, [sp, #-16]!
- mov x29, sp
-alternative_if ARM64_SVE
- bl __arm_smccc_sve_check
-alternative_else_nop_endif
\instr #0
- ldr x4, [sp, #16]
+ ldr x4, [sp]
stp x0, x1, [x4, #ARM_SMCCC_RES_X0_OFFS]
stp x2, x3, [x4, #ARM_SMCCC_RES_X2_OFFS]
- ldr x4, [sp, #24]
+ ldr x4, [sp, #8]
cbz x4, 1f /* no quirk structure */
ldr x9, [x4, #ARM_SMCCC_QUIRK_ID_OFFS]
cmp x9, #ARM_SMCCC_QUIRK_QCOM_A6
b.ne 1f
str x6, [x4, ARM_SMCCC_QUIRK_STATE_OFFS]
-1: ldp x29, x30, [sp], #16
- ret
+1: ret
.endm
/*
diff --git a/drivers/firmware/smccc/smccc.c b/drivers/firmware/smccc/smccc.c
index d670635914ec..a74600d9f2d7 100644
--- a/drivers/firmware/smccc/smccc.c
+++ b/drivers/firmware/smccc/smccc.c
@@ -16,7 +16,6 @@ static u32 smccc_version = ARM_SMCCC_VERSION_1_0;
static enum arm_smccc_conduit smccc_conduit = SMCCC_CONDUIT_NONE;
bool __ro_after_init smccc_trng_available = false;
-u64 __ro_after_init smccc_has_sve_hint = false;
s32 __ro_after_init smccc_soc_id_version = SMCCC_RET_NOT_SUPPORTED;
s32 __ro_after_init smccc_soc_id_revision = SMCCC_RET_NOT_SUPPORTED;
@@ -28,9 +27,6 @@ void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit)
smccc_conduit = conduit;
smccc_trng_available = smccc_probe_trng();
- if (IS_ENABLED(CONFIG_ARM64_SVE) &&
- smccc_version >= ARM_SMCCC_VERSION_1_3)
- smccc_has_sve_hint = true;
if ((smccc_version >= ARM_SMCCC_VERSION_1_2) &&
(smccc_conduit != SMCCC_CONDUIT_NONE)) {
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index f59099a213d0..67f6fdf2e7cd 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -315,8 +315,6 @@ u32 arm_smccc_get_version(void);
void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit);
-extern u64 smccc_has_sve_hint;
-
/**
* arm_smccc_get_soc_id_version()
*
@@ -414,15 +412,6 @@ struct arm_smccc_quirk {
} state;
};
-/**
- * __arm_smccc_sve_check() - Set the SVE hint bit when doing SMC calls
- *
- * Sets the SMCCC hint bit to indicate if there is live state in the SVE
- * registers, this modifies x0 in place and should never be called from C
- * code.
- */
-asmlinkage unsigned long __arm_smccc_sve_check(unsigned long x0);
-
/**
* __arm_smccc_smc() - make SMC calls
* @a0-a7: arguments passed in registers 0 to 7
@@ -490,20 +479,6 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
#endif
-/* nVHE hypervisor doesn't have a current thread so needs separate checks */
-#if defined(CONFIG_ARM64_SVE) && !defined(__KVM_NVHE_HYPERVISOR__)
-
-#define SMCCC_SVE_CHECK ALTERNATIVE("nop \n", "bl __arm_smccc_sve_check \n", \
- ARM64_SVE)
-#define smccc_sve_clobbers "x16", "x30", "cc",
-
-#else
-
-#define SMCCC_SVE_CHECK
-#define smccc_sve_clobbers
-
-#endif
-
#define __constraint_read_2 "r" (arg0)
#define __constraint_read_3 __constraint_read_2, "r" (arg1)
#define __constraint_read_4 __constraint_read_3, "r" (arg2)
@@ -574,12 +549,11 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
register unsigned long r3 asm("r3"); \
CONCATENATE(__declare_arg_, \
COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__); \
- asm volatile(SMCCC_SVE_CHECK \
- inst "\n" : \
+ asm volatile(inst "\n" : \
"=r" (r0), "=r" (r1), "=r" (r2), "=r" (r3) \
: CONCATENATE(__constraint_read_, \
COUNT_ARGS(__VA_ARGS__)) \
- : smccc_sve_clobbers "memory"); \
+ : "memory"); \
if (___res) \
*___res = (typeof(*___res)){r0, r1, r2, r3}; \
} while (0)
@@ -628,7 +602,7 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
asm ("" : \
: CONCATENATE(__constraint_read_, \
COUNT_ARGS(__VA_ARGS__)) \
- : smccc_sve_clobbers "memory"); \
+ : "memory"); \
if (___res) \
___res->a0 = SMCCC_RET_NOT_SUPPORTED; \
} while (0)
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 8c462d56487e3abdbf8a61cedfe7c795a54f4a78
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024110954-gambling-matador-1fff@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 8c462d56487e3abdbf8a61cedfe7c795a54f4a78 Mon Sep 17 00:00:00 2001
From: Mark Rutland <mark.rutland(a)arm.com>
Date: Wed, 6 Nov 2024 16:04:48 +0000
Subject: [PATCH] arm64: smccc: Remove broken support for SMCCCv1.3 SVE discard
hint
SMCCCv1.3 added a hint bit which callers can set in an SMCCC function ID
(AKA "FID") to indicate that it is acceptable for the SMCCC
implementation to discard SVE and/or SME state over a specific SMCCC
call. The kernel support for using this hint is broken and SMCCC calls
may clobber the SVE and/or SME state of arbitrary tasks, though FPSIMD
state is unaffected.
The kernel support is intended to use the hint when there is no SVE or
SME state to save, and to do this it checks whether TIF_FOREIGN_FPSTATE
is set or TIF_SVE is clear in assembly code:
| ldr <flags>, [<current_task>, #TSK_TI_FLAGS]
| tbnz <flags>, #TIF_FOREIGN_FPSTATE, 1f // Any live FP state?
| tbnz <flags>, #TIF_SVE, 2f // Does that state include SVE?
|
| 1: orr <fid>, <fid>, ARM_SMCCC_1_3_SVE_HINT
| 2:
| << SMCCC call using FID >>
This is not safe as-is:
(1) SMCCC calls can be made in a preemptible context and preemption can
result in TIF_FOREIGN_FPSTATE being set or cleared at arbitrary
points in time. Thus checking for TIF_FOREIGN_FPSTATE provides no
guarantee.
(2) TIF_FOREIGN_FPSTATE only indicates that the live FP/SVE/SME state in
the CPU does not belong to the current task, and does not indicate
that clobbering this state is acceptable.
When the live CPU state is clobbered it is necessary to update
fpsimd_last_state.st to ensure that a subsequent context switch will
reload FP/SVE/SME state from memory rather than consuming the
clobbered state. This and the SMCCC call itself must happen in a
critical section with preemption disabled to avoid races.
(3) Live SVE/SME state can exist with TIF_SVE clear (e.g. with only
TIF_SME set), and checking TIF_SVE alone is insufficient.
Remove the broken support for the SMCCCv1.3 SVE saving hint. This is
effectively a revert of commits:
* cfa7ff959a78 ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint")
* a7c3acca5380 ("arm64: smccc: Save lr before calling __arm_smccc_sve_check()")
... leaving behind the ARM_SMCCC_VERSION_1_3 and ARM_SMCCC_1_3_SVE_HINT
definitions, since these are simply definitions from the SMCCC
specification, and the latter is used in KVM via ARM_SMCCC_CALL_HINTS.
If we want to bring this back in future, we'll probably want to handle
this logic in C where we can use all the usual FPSIMD/SVE/SME helper
functions, and that'll likely require some rework of the SMCCC code
and/or its callers.
Fixes: cfa7ff959a78 ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint")
Signed-off-by: Mark Rutland <mark.rutland(a)arm.com>
Cc: Ard Biesheuvel <ardb(a)kernel.org>
Cc: Catalin Marinas <catalin.marinas(a)arm.com>
Cc: Marc Zyngier <maz(a)kernel.org>
Cc: Mark Brown <broonie(a)kernel.org>
Cc: Will Deacon <will(a)kernel.org>
Cc: stable(a)vger.kernel.org
Reviewed-by: Mark Brown <broonie(a)kernel.org>
Link: https://lore.kernel.org/r/20241106160448.2712997-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will(a)kernel.org>
diff --git a/arch/arm64/kernel/smccc-call.S b/arch/arm64/kernel/smccc-call.S
index 487381164ff6..2def9d0dd3dd 100644
--- a/arch/arm64/kernel/smccc-call.S
+++ b/arch/arm64/kernel/smccc-call.S
@@ -7,48 +7,19 @@
#include <asm/asm-offsets.h>
#include <asm/assembler.h>
-#include <asm/thread_info.h>
-
-/*
- * If we have SMCCC v1.3 and (as is likely) no SVE state in
- * the registers then set the SMCCC hint bit to say there's no
- * need to preserve it. Do this by directly adjusting the SMCCC
- * function value which is already stored in x0 ready to be called.
- */
-SYM_FUNC_START(__arm_smccc_sve_check)
-
- ldr_l x16, smccc_has_sve_hint
- cbz x16, 2f
-
- get_current_task x16
- ldr x16, [x16, #TSK_TI_FLAGS]
- tbnz x16, #TIF_FOREIGN_FPSTATE, 1f // Any live FP state?
- tbnz x16, #TIF_SVE, 2f // Does that state include SVE?
-
-1: orr x0, x0, ARM_SMCCC_1_3_SVE_HINT
-
-2: ret
-SYM_FUNC_END(__arm_smccc_sve_check)
-EXPORT_SYMBOL(__arm_smccc_sve_check)
.macro SMCCC instr
- stp x29, x30, [sp, #-16]!
- mov x29, sp
-alternative_if ARM64_SVE
- bl __arm_smccc_sve_check
-alternative_else_nop_endif
\instr #0
- ldr x4, [sp, #16]
+ ldr x4, [sp]
stp x0, x1, [x4, #ARM_SMCCC_RES_X0_OFFS]
stp x2, x3, [x4, #ARM_SMCCC_RES_X2_OFFS]
- ldr x4, [sp, #24]
+ ldr x4, [sp, #8]
cbz x4, 1f /* no quirk structure */
ldr x9, [x4, #ARM_SMCCC_QUIRK_ID_OFFS]
cmp x9, #ARM_SMCCC_QUIRK_QCOM_A6
b.ne 1f
str x6, [x4, ARM_SMCCC_QUIRK_STATE_OFFS]
-1: ldp x29, x30, [sp], #16
- ret
+1: ret
.endm
/*
diff --git a/drivers/firmware/smccc/smccc.c b/drivers/firmware/smccc/smccc.c
index d670635914ec..a74600d9f2d7 100644
--- a/drivers/firmware/smccc/smccc.c
+++ b/drivers/firmware/smccc/smccc.c
@@ -16,7 +16,6 @@ static u32 smccc_version = ARM_SMCCC_VERSION_1_0;
static enum arm_smccc_conduit smccc_conduit = SMCCC_CONDUIT_NONE;
bool __ro_after_init smccc_trng_available = false;
-u64 __ro_after_init smccc_has_sve_hint = false;
s32 __ro_after_init smccc_soc_id_version = SMCCC_RET_NOT_SUPPORTED;
s32 __ro_after_init smccc_soc_id_revision = SMCCC_RET_NOT_SUPPORTED;
@@ -28,9 +27,6 @@ void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit)
smccc_conduit = conduit;
smccc_trng_available = smccc_probe_trng();
- if (IS_ENABLED(CONFIG_ARM64_SVE) &&
- smccc_version >= ARM_SMCCC_VERSION_1_3)
- smccc_has_sve_hint = true;
if ((smccc_version >= ARM_SMCCC_VERSION_1_2) &&
(smccc_conduit != SMCCC_CONDUIT_NONE)) {
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index f59099a213d0..67f6fdf2e7cd 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -315,8 +315,6 @@ u32 arm_smccc_get_version(void);
void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit);
-extern u64 smccc_has_sve_hint;
-
/**
* arm_smccc_get_soc_id_version()
*
@@ -414,15 +412,6 @@ struct arm_smccc_quirk {
} state;
};
-/**
- * __arm_smccc_sve_check() - Set the SVE hint bit when doing SMC calls
- *
- * Sets the SMCCC hint bit to indicate if there is live state in the SVE
- * registers, this modifies x0 in place and should never be called from C
- * code.
- */
-asmlinkage unsigned long __arm_smccc_sve_check(unsigned long x0);
-
/**
* __arm_smccc_smc() - make SMC calls
* @a0-a7: arguments passed in registers 0 to 7
@@ -490,20 +479,6 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
#endif
-/* nVHE hypervisor doesn't have a current thread so needs separate checks */
-#if defined(CONFIG_ARM64_SVE) && !defined(__KVM_NVHE_HYPERVISOR__)
-
-#define SMCCC_SVE_CHECK ALTERNATIVE("nop \n", "bl __arm_smccc_sve_check \n", \
- ARM64_SVE)
-#define smccc_sve_clobbers "x16", "x30", "cc",
-
-#else
-
-#define SMCCC_SVE_CHECK
-#define smccc_sve_clobbers
-
-#endif
-
#define __constraint_read_2 "r" (arg0)
#define __constraint_read_3 __constraint_read_2, "r" (arg1)
#define __constraint_read_4 __constraint_read_3, "r" (arg2)
@@ -574,12 +549,11 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
register unsigned long r3 asm("r3"); \
CONCATENATE(__declare_arg_, \
COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__); \
- asm volatile(SMCCC_SVE_CHECK \
- inst "\n" : \
+ asm volatile(inst "\n" : \
"=r" (r0), "=r" (r1), "=r" (r2), "=r" (r3) \
: CONCATENATE(__constraint_read_, \
COUNT_ARGS(__VA_ARGS__)) \
- : smccc_sve_clobbers "memory"); \
+ : "memory"); \
if (___res) \
*___res = (typeof(*___res)){r0, r1, r2, r3}; \
} while (0)
@@ -628,7 +602,7 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
asm ("" : \
: CONCATENATE(__constraint_read_, \
COUNT_ARGS(__VA_ARGS__)) \
- : smccc_sve_clobbers "memory"); \
+ : "memory"); \
if (___res) \
___res->a0 = SMCCC_RET_NOT_SUPPORTED; \
} while (0)
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 751ecf6afd6568adc98f2a6052315552c0483d18
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024110930-pelt-think-f459@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 751ecf6afd6568adc98f2a6052315552c0483d18 Mon Sep 17 00:00:00 2001
From: Mark Brown <broonie(a)kernel.org>
Date: Wed, 30 Oct 2024 20:23:50 +0000
Subject: [PATCH] arm64/sve: Discard stale CPU state when handling SVE traps
The logic for handling SVE traps manipulates saved FPSIMD/SVE state
incorrectly, and a race with preemption can result in a task having
TIF_SVE set and TIF_FOREIGN_FPSTATE clear even though the live CPU state
is stale (e.g. with SVE traps enabled). This has been observed to result
in warnings from do_sve_acc() where SVE traps are not expected while
TIF_SVE is set:
| if (test_and_set_thread_flag(TIF_SVE))
| WARN_ON(1); /* SVE access shouldn't have trapped */
Warnings of this form have been reported intermittently, e.g.
https://lore.kernel.org/linux-arm-kernel/CA+G9fYtEGe_DhY2Ms7+L7NKsLYUomGsgq…https://lore.kernel.org/linux-arm-kernel/000000000000511e9a060ce5a45c@googl…
The race can occur when the SVE trap handler is preempted before and
after manipulating the saved FPSIMD/SVE state, starting and ending on
the same CPU, e.g.
| void do_sve_acc(unsigned long esr, struct pt_regs *regs)
| {
| // Trap on CPU 0 with TIF_SVE clear, SVE traps enabled
| // task->fpsimd_cpu is 0.
| // per_cpu_ptr(&fpsimd_last_state, 0) is task.
|
| ...
|
| // Preempted; migrated from CPU 0 to CPU 1.
| // TIF_FOREIGN_FPSTATE is set.
|
| get_cpu_fpsimd_context();
|
| if (test_and_set_thread_flag(TIF_SVE))
| WARN_ON(1); /* SVE access shouldn't have trapped */
|
| sve_init_regs() {
| if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) {
| ...
| } else {
| fpsimd_to_sve(current);
| current->thread.fp_type = FP_STATE_SVE;
| }
| }
|
| put_cpu_fpsimd_context();
|
| // Preempted; migrated from CPU 1 to CPU 0.
| // task->fpsimd_cpu is still 0
| // If per_cpu_ptr(&fpsimd_last_state, 0) is still task then:
| // - Stale HW state is reused (with SVE traps enabled)
| // - TIF_FOREIGN_FPSTATE is cleared
| // - A return to userspace skips HW state restore
| }
Fix the case where the state is not live and TIF_FOREIGN_FPSTATE is set
by calling fpsimd_flush_task_state() to detach from the saved CPU
state. This ensures that a subsequent context switch will not reuse the
stale CPU state, and will instead set TIF_FOREIGN_FPSTATE, forcing the
new state to be reloaded from memory prior to a return to userspace.
Fixes: cccb78ce89c4 ("arm64/sve: Rework SVE access trap to convert state in registers")
Reported-by: Mark Rutland <mark.rutland(a)arm.com>
Signed-off-by: Mark Brown <broonie(a)kernel.org>
Cc: stable(a)vger.kernel.org
Reviewed-by: Mark Rutland <mark.rutland(a)arm.com>
Link: https://lore.kernel.org/r/20241030-arm64-fpsimd-foreign-flush-v1-1-bd7bd669…
Signed-off-by: Will Deacon <will(a)kernel.org>
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 77006df20a75..6d21971ae559 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -1367,6 +1367,7 @@ static void sve_init_regs(void)
} else {
fpsimd_to_sve(current);
current->thread.fp_type = FP_STATE_SVE;
+ fpsimd_flush_task_state(current);
}
}
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 751ecf6afd6568adc98f2a6052315552c0483d18
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024110929-splendid-engine-1d44@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 751ecf6afd6568adc98f2a6052315552c0483d18 Mon Sep 17 00:00:00 2001
From: Mark Brown <broonie(a)kernel.org>
Date: Wed, 30 Oct 2024 20:23:50 +0000
Subject: [PATCH] arm64/sve: Discard stale CPU state when handling SVE traps
The logic for handling SVE traps manipulates saved FPSIMD/SVE state
incorrectly, and a race with preemption can result in a task having
TIF_SVE set and TIF_FOREIGN_FPSTATE clear even though the live CPU state
is stale (e.g. with SVE traps enabled). This has been observed to result
in warnings from do_sve_acc() where SVE traps are not expected while
TIF_SVE is set:
| if (test_and_set_thread_flag(TIF_SVE))
| WARN_ON(1); /* SVE access shouldn't have trapped */
Warnings of this form have been reported intermittently, e.g.
https://lore.kernel.org/linux-arm-kernel/CA+G9fYtEGe_DhY2Ms7+L7NKsLYUomGsgq…https://lore.kernel.org/linux-arm-kernel/000000000000511e9a060ce5a45c@googl…
The race can occur when the SVE trap handler is preempted before and
after manipulating the saved FPSIMD/SVE state, starting and ending on
the same CPU, e.g.
| void do_sve_acc(unsigned long esr, struct pt_regs *regs)
| {
| // Trap on CPU 0 with TIF_SVE clear, SVE traps enabled
| // task->fpsimd_cpu is 0.
| // per_cpu_ptr(&fpsimd_last_state, 0) is task.
|
| ...
|
| // Preempted; migrated from CPU 0 to CPU 1.
| // TIF_FOREIGN_FPSTATE is set.
|
| get_cpu_fpsimd_context();
|
| if (test_and_set_thread_flag(TIF_SVE))
| WARN_ON(1); /* SVE access shouldn't have trapped */
|
| sve_init_regs() {
| if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) {
| ...
| } else {
| fpsimd_to_sve(current);
| current->thread.fp_type = FP_STATE_SVE;
| }
| }
|
| put_cpu_fpsimd_context();
|
| // Preempted; migrated from CPU 1 to CPU 0.
| // task->fpsimd_cpu is still 0
| // If per_cpu_ptr(&fpsimd_last_state, 0) is still task then:
| // - Stale HW state is reused (with SVE traps enabled)
| // - TIF_FOREIGN_FPSTATE is cleared
| // - A return to userspace skips HW state restore
| }
Fix the case where the state is not live and TIF_FOREIGN_FPSTATE is set
by calling fpsimd_flush_task_state() to detach from the saved CPU
state. This ensures that a subsequent context switch will not reuse the
stale CPU state, and will instead set TIF_FOREIGN_FPSTATE, forcing the
new state to be reloaded from memory prior to a return to userspace.
Fixes: cccb78ce89c4 ("arm64/sve: Rework SVE access trap to convert state in registers")
Reported-by: Mark Rutland <mark.rutland(a)arm.com>
Signed-off-by: Mark Brown <broonie(a)kernel.org>
Cc: stable(a)vger.kernel.org
Reviewed-by: Mark Rutland <mark.rutland(a)arm.com>
Link: https://lore.kernel.org/r/20241030-arm64-fpsimd-foreign-flush-v1-1-bd7bd669…
Signed-off-by: Will Deacon <will(a)kernel.org>
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 77006df20a75..6d21971ae559 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -1367,6 +1367,7 @@ static void sve_init_regs(void)
} else {
fpsimd_to_sve(current);
current->thread.fp_type = FP_STATE_SVE;
+ fpsimd_flush_task_state(current);
}
}
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x 135496c208ba26fd68cdef10b64ed7a91ac9a7ff
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024110948-marathon-slouching-399d@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 135496c208ba26fd68cdef10b64ed7a91ac9a7ff Mon Sep 17 00:00:00 2001
From: Ming-Hung Tsai <mtsai(a)redhat.com>
Date: Tue, 22 Oct 2024 15:12:49 +0800
Subject: [PATCH] dm cache: fix flushing uninitialized delayed_work on
cache_ctr error
An unexpected WARN_ON from flush_work() may occur when cache creation
fails, caused by destroying the uninitialized delayed_work waker in the
error path of cache_create(). For example, the warning appears on the
superblock checksum error.
Reproduce steps:
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"
dmsetup create cdata --table "0 65536 linear /dev/sdc 8192"
dmsetup create corig --table "0 524288 linear /dev/sdc 262144"
dd if=/dev/urandom of=/dev/mapper/cmeta bs=4k count=1 oflag=direct
dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \
/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"
Kernel logs:
(snip)
WARNING: CPU: 0 PID: 84 at kernel/workqueue.c:4178 __flush_work+0x5d4/0x890
Fix by pulling out the cancel_delayed_work_sync() from the constructor's
error path. This patch doesn't affect the use-after-free fix for
concurrent dm_resume and dm_destroy (commit 6a459d8edbdb ("dm cache: Fix
UAF in destroy()")) as cache_dtr is not changed.
Signed-off-by: Ming-Hung Tsai <mtsai(a)redhat.com>
Fixes: 6a459d8edbdb ("dm cache: Fix UAF in destroy()")
Cc: stable(a)vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka(a)redhat.com>
Acked-by: Joe Thornber <thornber(a)redhat.com>
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 90772b42c234..68e9a1abd303 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -1905,16 +1905,13 @@ static void check_migrations(struct work_struct *ws)
* This function gets called on the error paths of the constructor, so we
* have to cope with a partially initialised struct.
*/
-static void destroy(struct cache *cache)
+static void __destroy(struct cache *cache)
{
- unsigned int i;
-
mempool_exit(&cache->migration_pool);
if (cache->prison)
dm_bio_prison_destroy_v2(cache->prison);
- cancel_delayed_work_sync(&cache->waker);
if (cache->wq)
destroy_workqueue(cache->wq);
@@ -1942,13 +1939,22 @@ static void destroy(struct cache *cache)
if (cache->policy)
dm_cache_policy_destroy(cache->policy);
+ bioset_exit(&cache->bs);
+
+ kfree(cache);
+}
+
+static void destroy(struct cache *cache)
+{
+ unsigned int i;
+
+ cancel_delayed_work_sync(&cache->waker);
+
for (i = 0; i < cache->nr_ctr_args ; i++)
kfree(cache->ctr_args[i]);
kfree(cache->ctr_args);
- bioset_exit(&cache->bs);
-
- kfree(cache);
+ __destroy(cache);
}
static void cache_dtr(struct dm_target *ti)
@@ -2561,7 +2567,7 @@ static int cache_create(struct cache_args *ca, struct cache **result)
*result = cache;
return 0;
bad:
- destroy(cache);
+ __destroy(cache);
return r;
}
@@ -2612,7 +2618,7 @@ static int cache_ctr(struct dm_target *ti, unsigned int argc, char **argv)
r = copy_ctr_args(cache, argc - 3, (const char **)argv + 3);
if (r) {
- destroy(cache);
+ __destroy(cache);
goto out;
}
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 135496c208ba26fd68cdef10b64ed7a91ac9a7ff
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024110947-footbath-census-7efa@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 135496c208ba26fd68cdef10b64ed7a91ac9a7ff Mon Sep 17 00:00:00 2001
From: Ming-Hung Tsai <mtsai(a)redhat.com>
Date: Tue, 22 Oct 2024 15:12:49 +0800
Subject: [PATCH] dm cache: fix flushing uninitialized delayed_work on
cache_ctr error
An unexpected WARN_ON from flush_work() may occur when cache creation
fails, caused by destroying the uninitialized delayed_work waker in the
error path of cache_create(). For example, the warning appears on the
superblock checksum error.
Reproduce steps:
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"
dmsetup create cdata --table "0 65536 linear /dev/sdc 8192"
dmsetup create corig --table "0 524288 linear /dev/sdc 262144"
dd if=/dev/urandom of=/dev/mapper/cmeta bs=4k count=1 oflag=direct
dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \
/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"
Kernel logs:
(snip)
WARNING: CPU: 0 PID: 84 at kernel/workqueue.c:4178 __flush_work+0x5d4/0x890
Fix by pulling out the cancel_delayed_work_sync() from the constructor's
error path. This patch doesn't affect the use-after-free fix for
concurrent dm_resume and dm_destroy (commit 6a459d8edbdb ("dm cache: Fix
UAF in destroy()")) as cache_dtr is not changed.
Signed-off-by: Ming-Hung Tsai <mtsai(a)redhat.com>
Fixes: 6a459d8edbdb ("dm cache: Fix UAF in destroy()")
Cc: stable(a)vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka(a)redhat.com>
Acked-by: Joe Thornber <thornber(a)redhat.com>
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 90772b42c234..68e9a1abd303 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -1905,16 +1905,13 @@ static void check_migrations(struct work_struct *ws)
* This function gets called on the error paths of the constructor, so we
* have to cope with a partially initialised struct.
*/
-static void destroy(struct cache *cache)
+static void __destroy(struct cache *cache)
{
- unsigned int i;
-
mempool_exit(&cache->migration_pool);
if (cache->prison)
dm_bio_prison_destroy_v2(cache->prison);
- cancel_delayed_work_sync(&cache->waker);
if (cache->wq)
destroy_workqueue(cache->wq);
@@ -1942,13 +1939,22 @@ static void destroy(struct cache *cache)
if (cache->policy)
dm_cache_policy_destroy(cache->policy);
+ bioset_exit(&cache->bs);
+
+ kfree(cache);
+}
+
+static void destroy(struct cache *cache)
+{
+ unsigned int i;
+
+ cancel_delayed_work_sync(&cache->waker);
+
for (i = 0; i < cache->nr_ctr_args ; i++)
kfree(cache->ctr_args[i]);
kfree(cache->ctr_args);
- bioset_exit(&cache->bs);
-
- kfree(cache);
+ __destroy(cache);
}
static void cache_dtr(struct dm_target *ti)
@@ -2561,7 +2567,7 @@ static int cache_create(struct cache_args *ca, struct cache **result)
*result = cache;
return 0;
bad:
- destroy(cache);
+ __destroy(cache);
return r;
}
@@ -2612,7 +2618,7 @@ static int cache_ctr(struct dm_target *ti, unsigned int argc, char **argv)
r = copy_ctr_args(cache, argc - 3, (const char **)argv + 3);
if (r) {
- destroy(cache);
+ __destroy(cache);
goto out;
}
The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 135496c208ba26fd68cdef10b64ed7a91ac9a7ff
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024110946-juniper-subfloor-2651@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 135496c208ba26fd68cdef10b64ed7a91ac9a7ff Mon Sep 17 00:00:00 2001
From: Ming-Hung Tsai <mtsai(a)redhat.com>
Date: Tue, 22 Oct 2024 15:12:49 +0800
Subject: [PATCH] dm cache: fix flushing uninitialized delayed_work on
cache_ctr error
An unexpected WARN_ON from flush_work() may occur when cache creation
fails, caused by destroying the uninitialized delayed_work waker in the
error path of cache_create(). For example, the warning appears on the
superblock checksum error.
Reproduce steps:
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"
dmsetup create cdata --table "0 65536 linear /dev/sdc 8192"
dmsetup create corig --table "0 524288 linear /dev/sdc 262144"
dd if=/dev/urandom of=/dev/mapper/cmeta bs=4k count=1 oflag=direct
dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \
/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"
Kernel logs:
(snip)
WARNING: CPU: 0 PID: 84 at kernel/workqueue.c:4178 __flush_work+0x5d4/0x890
Fix by pulling out the cancel_delayed_work_sync() from the constructor's
error path. This patch doesn't affect the use-after-free fix for
concurrent dm_resume and dm_destroy (commit 6a459d8edbdb ("dm cache: Fix
UAF in destroy()")) as cache_dtr is not changed.
Signed-off-by: Ming-Hung Tsai <mtsai(a)redhat.com>
Fixes: 6a459d8edbdb ("dm cache: Fix UAF in destroy()")
Cc: stable(a)vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka(a)redhat.com>
Acked-by: Joe Thornber <thornber(a)redhat.com>
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 90772b42c234..68e9a1abd303 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -1905,16 +1905,13 @@ static void check_migrations(struct work_struct *ws)
* This function gets called on the error paths of the constructor, so we
* have to cope with a partially initialised struct.
*/
-static void destroy(struct cache *cache)
+static void __destroy(struct cache *cache)
{
- unsigned int i;
-
mempool_exit(&cache->migration_pool);
if (cache->prison)
dm_bio_prison_destroy_v2(cache->prison);
- cancel_delayed_work_sync(&cache->waker);
if (cache->wq)
destroy_workqueue(cache->wq);
@@ -1942,13 +1939,22 @@ static void destroy(struct cache *cache)
if (cache->policy)
dm_cache_policy_destroy(cache->policy);
+ bioset_exit(&cache->bs);
+
+ kfree(cache);
+}
+
+static void destroy(struct cache *cache)
+{
+ unsigned int i;
+
+ cancel_delayed_work_sync(&cache->waker);
+
for (i = 0; i < cache->nr_ctr_args ; i++)
kfree(cache->ctr_args[i]);
kfree(cache->ctr_args);
- bioset_exit(&cache->bs);
-
- kfree(cache);
+ __destroy(cache);
}
static void cache_dtr(struct dm_target *ti)
@@ -2561,7 +2567,7 @@ static int cache_create(struct cache_args *ca, struct cache **result)
*result = cache;
return 0;
bad:
- destroy(cache);
+ __destroy(cache);
return r;
}
@@ -2612,7 +2618,7 @@ static int cache_ctr(struct dm_target *ti, unsigned int argc, char **argv)
r = copy_ctr_args(cache, argc - 3, (const char **)argv + 3);
if (r) {
- destroy(cache);
+ __destroy(cache);
goto out;
}
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 135496c208ba26fd68cdef10b64ed7a91ac9a7ff
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024110945-caress-unmasked-1f81@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 135496c208ba26fd68cdef10b64ed7a91ac9a7ff Mon Sep 17 00:00:00 2001
From: Ming-Hung Tsai <mtsai(a)redhat.com>
Date: Tue, 22 Oct 2024 15:12:49 +0800
Subject: [PATCH] dm cache: fix flushing uninitialized delayed_work on
cache_ctr error
An unexpected WARN_ON from flush_work() may occur when cache creation
fails, caused by destroying the uninitialized delayed_work waker in the
error path of cache_create(). For example, the warning appears on the
superblock checksum error.
Reproduce steps:
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"
dmsetup create cdata --table "0 65536 linear /dev/sdc 8192"
dmsetup create corig --table "0 524288 linear /dev/sdc 262144"
dd if=/dev/urandom of=/dev/mapper/cmeta bs=4k count=1 oflag=direct
dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \
/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"
Kernel logs:
(snip)
WARNING: CPU: 0 PID: 84 at kernel/workqueue.c:4178 __flush_work+0x5d4/0x890
Fix by pulling out the cancel_delayed_work_sync() from the constructor's
error path. This patch doesn't affect the use-after-free fix for
concurrent dm_resume and dm_destroy (commit 6a459d8edbdb ("dm cache: Fix
UAF in destroy()")) as cache_dtr is not changed.
Signed-off-by: Ming-Hung Tsai <mtsai(a)redhat.com>
Fixes: 6a459d8edbdb ("dm cache: Fix UAF in destroy()")
Cc: stable(a)vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka(a)redhat.com>
Acked-by: Joe Thornber <thornber(a)redhat.com>
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 90772b42c234..68e9a1abd303 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -1905,16 +1905,13 @@ static void check_migrations(struct work_struct *ws)
* This function gets called on the error paths of the constructor, so we
* have to cope with a partially initialised struct.
*/
-static void destroy(struct cache *cache)
+static void __destroy(struct cache *cache)
{
- unsigned int i;
-
mempool_exit(&cache->migration_pool);
if (cache->prison)
dm_bio_prison_destroy_v2(cache->prison);
- cancel_delayed_work_sync(&cache->waker);
if (cache->wq)
destroy_workqueue(cache->wq);
@@ -1942,13 +1939,22 @@ static void destroy(struct cache *cache)
if (cache->policy)
dm_cache_policy_destroy(cache->policy);
+ bioset_exit(&cache->bs);
+
+ kfree(cache);
+}
+
+static void destroy(struct cache *cache)
+{
+ unsigned int i;
+
+ cancel_delayed_work_sync(&cache->waker);
+
for (i = 0; i < cache->nr_ctr_args ; i++)
kfree(cache->ctr_args[i]);
kfree(cache->ctr_args);
- bioset_exit(&cache->bs);
-
- kfree(cache);
+ __destroy(cache);
}
static void cache_dtr(struct dm_target *ti)
@@ -2561,7 +2567,7 @@ static int cache_create(struct cache_args *ca, struct cache **result)
*result = cache;
return 0;
bad:
- destroy(cache);
+ __destroy(cache);
return r;
}
@@ -2612,7 +2618,7 @@ static int cache_ctr(struct dm_target *ti, unsigned int argc, char **argv)
r = copy_ctr_args(cache, argc - 3, (const char **)argv + 3);
if (r) {
- destroy(cache);
+ __destroy(cache);
goto out;
}
The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 4f26c95ffc21a91281429ed60180619bae19ae92
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024110902-backslid-snagged-6d02@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 4f26c95ffc21a91281429ed60180619bae19ae92 Mon Sep 17 00:00:00 2001
From: Tom Chung <chiahsuan.chung(a)amd.com>
Date: Wed, 9 Oct 2024 17:09:38 +0800
Subject: [PATCH] drm/amd/display: Fix brightness level not retained over
reboot
[Why]
During boot up and resume the DC layer will reset the panel
brightness to fix a flicker issue.
It will cause the dm->actual_brightness is not the current panel
brightness level. (the dm->brightness is the correct panel level)
[How]
Set the backlight level after do the set mode.
Cc: Mario Limonciello <mario.limonciello(a)amd.com>
Cc: Alex Deucher <alexander.deucher(a)amd.com>
Fixes: d9e865826c20 ("drm/amd/display: Simplify brightness initialization")
Reported-by: Mark Herbert <mark.herbert42(a)gmail.com>
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3655
Reviewed-by: Sun peng Li <sunpeng.li(a)amd.com>
Signed-off-by: Tom Chung <chiahsuan.chung(a)amd.com>
Signed-off-by: Zaeem Mohamed <zaeem.mohamed(a)amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler(a)amd.com>
Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com>
(cherry picked from commit 7875afafba84817b791be6d2282b836695146060)
Cc: stable(a)vger.kernel.org
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 13421a58210d..07e9ce99694f 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -9429,6 +9429,7 @@ static void amdgpu_dm_commit_streams(struct drm_atomic_state *state,
bool mode_set_reset_required = false;
u32 i;
struct dc_commit_streams_params params = {dc_state->streams, dc_state->stream_count};
+ bool set_backlight_level = false;
/* Disable writeback */
for_each_old_connector_in_state(state, connector, old_con_state, i) {
@@ -9548,6 +9549,7 @@ static void amdgpu_dm_commit_streams(struct drm_atomic_state *state,
acrtc->hw_mode = new_crtc_state->mode;
crtc->hwmode = new_crtc_state->mode;
mode_set_reset_required = true;
+ set_backlight_level = true;
} else if (modereset_required(new_crtc_state)) {
drm_dbg_atomic(dev,
"Atomic commit: RESET. crtc id %d:[%p]\n",
@@ -9599,6 +9601,19 @@ static void amdgpu_dm_commit_streams(struct drm_atomic_state *state,
acrtc->otg_inst = status->primary_otg_inst;
}
}
+
+ /* During boot up and resume the DC layer will reset the panel brightness
+ * to fix a flicker issue.
+ * It will cause the dm->actual_brightness is not the current panel brightness
+ * level. (the dm->brightness is the correct panel level)
+ * So we set the backlight level with dm->brightness value after set mode
+ */
+ if (set_backlight_level) {
+ for (i = 0; i < dm->num_of_edps; i++) {
+ if (dm->backlight_dev[i])
+ amdgpu_dm_backlight_set_level(dm, i, dm->brightness[i]);
+ }
+ }
}
static void dm_set_writeback(struct amdgpu_display_manager *dm,