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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 758c9373d84168dc7d039cf85a0e920046b17b41 Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto(a)kernel.org>
Date: Thu, 3 Dec 2020 21:07:05 -0800
Subject: [PATCH] membarrier: Explicitly sync remote cores when SYNC_CORE is
requested
membarrier() does not explicitly sync_core() remote CPUs; instead, it
relies on the assumption that an IPI will result in a core sync. On x86,
this may be true in practice, but it's not architecturally reliable. In
particular, the SDM and APM do not appear to guarantee that interrupt
delivery is serializing. While IRET does serialize, IPI return can
schedule, thereby switching to another task in the same mm that was
sleeping in a syscall. The new task could then SYSRET back to usermode
without ever executing IRET.
Make this more robust by explicitly calling sync_core_before_usermode()
on remote cores. (This also helps people who search the kernel tree for
instances of sync_core() and sync_core_before_usermode() -- one might be
surprised that the core membarrier code doesn't currently show up in a
such a search.)
Fixes: 70216e18e519 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto(a)kernel.org>
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/776b448d5f7bd6b12690707f5ed67bcda7f1d427.16070583…
diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c
index 7d98ef5d3bcd..1c278dff4f2d 100644
--- a/kernel/sched/membarrier.c
+++ b/kernel/sched/membarrier.c
@@ -38,6 +38,23 @@ static void ipi_mb(void *info)
smp_mb(); /* IPIs should be serializing but paranoid. */
}
+static void ipi_sync_core(void *info)
+{
+ /*
+ * The smp_mb() in membarrier after all the IPIs is supposed to
+ * ensure that memory on remote CPUs that occur before the IPI
+ * become visible to membarrier()'s caller -- see scenario B in
+ * the big comment at the top of this file.
+ *
+ * A sync_core() would provide this guarantee, but
+ * sync_core_before_usermode() might end up being deferred until
+ * after membarrier()'s smp_mb().
+ */
+ smp_mb(); /* IPIs should be serializing but paranoid. */
+
+ sync_core_before_usermode();
+}
+
static void ipi_rseq(void *info)
{
/*
@@ -162,6 +179,7 @@ static int membarrier_private_expedited(int flags, int cpu_id)
if (!(atomic_read(&mm->membarrier_state) &
MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE_READY))
return -EPERM;
+ ipi_func = ipi_sync_core;
} else if (flags == MEMBARRIER_FLAG_RSEQ) {
if (!IS_ENABLED(CONFIG_RSEQ))
return -EINVAL;
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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 758c9373d84168dc7d039cf85a0e920046b17b41 Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto(a)kernel.org>
Date: Thu, 3 Dec 2020 21:07:05 -0800
Subject: [PATCH] membarrier: Explicitly sync remote cores when SYNC_CORE is
requested
membarrier() does not explicitly sync_core() remote CPUs; instead, it
relies on the assumption that an IPI will result in a core sync. On x86,
this may be true in practice, but it's not architecturally reliable. In
particular, the SDM and APM do not appear to guarantee that interrupt
delivery is serializing. While IRET does serialize, IPI return can
schedule, thereby switching to another task in the same mm that was
sleeping in a syscall. The new task could then SYSRET back to usermode
without ever executing IRET.
Make this more robust by explicitly calling sync_core_before_usermode()
on remote cores. (This also helps people who search the kernel tree for
instances of sync_core() and sync_core_before_usermode() -- one might be
surprised that the core membarrier code doesn't currently show up in a
such a search.)
Fixes: 70216e18e519 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto(a)kernel.org>
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/776b448d5f7bd6b12690707f5ed67bcda7f1d427.16070583…
diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c
index 7d98ef5d3bcd..1c278dff4f2d 100644
--- a/kernel/sched/membarrier.c
+++ b/kernel/sched/membarrier.c
@@ -38,6 +38,23 @@ static void ipi_mb(void *info)
smp_mb(); /* IPIs should be serializing but paranoid. */
}
+static void ipi_sync_core(void *info)
+{
+ /*
+ * The smp_mb() in membarrier after all the IPIs is supposed to
+ * ensure that memory on remote CPUs that occur before the IPI
+ * become visible to membarrier()'s caller -- see scenario B in
+ * the big comment at the top of this file.
+ *
+ * A sync_core() would provide this guarantee, but
+ * sync_core_before_usermode() might end up being deferred until
+ * after membarrier()'s smp_mb().
+ */
+ smp_mb(); /* IPIs should be serializing but paranoid. */
+
+ sync_core_before_usermode();
+}
+
static void ipi_rseq(void *info)
{
/*
@@ -162,6 +179,7 @@ static int membarrier_private_expedited(int flags, int cpu_id)
if (!(atomic_read(&mm->membarrier_state) &
MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE_READY))
return -EPERM;
+ ipi_func = ipi_sync_core;
} else if (flags == MEMBARRIER_FLAG_RSEQ) {
if (!IS_ENABLED(CONFIG_RSEQ))
return -EINVAL;
The patch below does not apply to the 5.9-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 758c9373d84168dc7d039cf85a0e920046b17b41 Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto(a)kernel.org>
Date: Thu, 3 Dec 2020 21:07:05 -0800
Subject: [PATCH] membarrier: Explicitly sync remote cores when SYNC_CORE is
requested
membarrier() does not explicitly sync_core() remote CPUs; instead, it
relies on the assumption that an IPI will result in a core sync. On x86,
this may be true in practice, but it's not architecturally reliable. In
particular, the SDM and APM do not appear to guarantee that interrupt
delivery is serializing. While IRET does serialize, IPI return can
schedule, thereby switching to another task in the same mm that was
sleeping in a syscall. The new task could then SYSRET back to usermode
without ever executing IRET.
Make this more robust by explicitly calling sync_core_before_usermode()
on remote cores. (This also helps people who search the kernel tree for
instances of sync_core() and sync_core_before_usermode() -- one might be
surprised that the core membarrier code doesn't currently show up in a
such a search.)
Fixes: 70216e18e519 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto(a)kernel.org>
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/776b448d5f7bd6b12690707f5ed67bcda7f1d427.16070583…
diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c
index 7d98ef5d3bcd..1c278dff4f2d 100644
--- a/kernel/sched/membarrier.c
+++ b/kernel/sched/membarrier.c
@@ -38,6 +38,23 @@ static void ipi_mb(void *info)
smp_mb(); /* IPIs should be serializing but paranoid. */
}
+static void ipi_sync_core(void *info)
+{
+ /*
+ * The smp_mb() in membarrier after all the IPIs is supposed to
+ * ensure that memory on remote CPUs that occur before the IPI
+ * become visible to membarrier()'s caller -- see scenario B in
+ * the big comment at the top of this file.
+ *
+ * A sync_core() would provide this guarantee, but
+ * sync_core_before_usermode() might end up being deferred until
+ * after membarrier()'s smp_mb().
+ */
+ smp_mb(); /* IPIs should be serializing but paranoid. */
+
+ sync_core_before_usermode();
+}
+
static void ipi_rseq(void *info)
{
/*
@@ -162,6 +179,7 @@ static int membarrier_private_expedited(int flags, int cpu_id)
if (!(atomic_read(&mm->membarrier_state) &
MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE_READY))
return -EPERM;
+ ipi_func = ipi_sync_core;
} else if (flags == MEMBARRIER_FLAG_RSEQ) {
if (!IS_ENABLED(CONFIG_RSEQ))
return -EINVAL;
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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 2ecedd7569080fd05c1a457e8af2165afecfa29f Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto(a)kernel.org>
Date: Thu, 3 Dec 2020 21:07:04 -0800
Subject: [PATCH] membarrier: Add an actual barrier before rseq_preempt()
It seems that most RSEQ membarrier users will expect any stores done before
the membarrier() syscall to be visible to the target task(s). While this
is extremely likely to be true in practice, nothing actually guarantees it
by a strict reading of the x86 manuals. Rather than providing this
guarantee by accident and potentially causing a problem down the road, just
add an explicit barrier.
Fixes: 70216e18e519 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto(a)kernel.org>
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/d3e7197e034fa4852afcf370ca49c30496e58e40.16070583…
diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c
index e23e74d52db5..7d98ef5d3bcd 100644
--- a/kernel/sched/membarrier.c
+++ b/kernel/sched/membarrier.c
@@ -40,6 +40,14 @@ static void ipi_mb(void *info)
static void ipi_rseq(void *info)
{
+ /*
+ * Ensure that all stores done by the calling thread are visible
+ * to the current task before the current task resumes. We could
+ * probably optimize this away on most architectures, but by the
+ * time we've already sent an IPI, the cost of the extra smp_mb()
+ * is negligible.
+ */
+ smp_mb();
rseq_preempt(current);
}
The patch below does not apply to the 5.9-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 2ecedd7569080fd05c1a457e8af2165afecfa29f Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto(a)kernel.org>
Date: Thu, 3 Dec 2020 21:07:04 -0800
Subject: [PATCH] membarrier: Add an actual barrier before rseq_preempt()
It seems that most RSEQ membarrier users will expect any stores done before
the membarrier() syscall to be visible to the target task(s). While this
is extremely likely to be true in practice, nothing actually guarantees it
by a strict reading of the x86 manuals. Rather than providing this
guarantee by accident and potentially causing a problem down the road, just
add an explicit barrier.
Fixes: 70216e18e519 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto(a)kernel.org>
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/d3e7197e034fa4852afcf370ca49c30496e58e40.16070583…
diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c
index e23e74d52db5..7d98ef5d3bcd 100644
--- a/kernel/sched/membarrier.c
+++ b/kernel/sched/membarrier.c
@@ -40,6 +40,14 @@ static void ipi_mb(void *info)
static void ipi_rseq(void *info)
{
+ /*
+ * Ensure that all stores done by the calling thread are visible
+ * to the current task before the current task resumes. We could
+ * probably optimize this away on most architectures, but by the
+ * time we've already sent an IPI, the cost of the extra smp_mb()
+ * is negligible.
+ */
+ smp_mb();
rseq_preempt(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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 2ecedd7569080fd05c1a457e8af2165afecfa29f Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto(a)kernel.org>
Date: Thu, 3 Dec 2020 21:07:04 -0800
Subject: [PATCH] membarrier: Add an actual barrier before rseq_preempt()
It seems that most RSEQ membarrier users will expect any stores done before
the membarrier() syscall to be visible to the target task(s). While this
is extremely likely to be true in practice, nothing actually guarantees it
by a strict reading of the x86 manuals. Rather than providing this
guarantee by accident and potentially causing a problem down the road, just
add an explicit barrier.
Fixes: 70216e18e519 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto(a)kernel.org>
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/d3e7197e034fa4852afcf370ca49c30496e58e40.16070583…
diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c
index e23e74d52db5..7d98ef5d3bcd 100644
--- a/kernel/sched/membarrier.c
+++ b/kernel/sched/membarrier.c
@@ -40,6 +40,14 @@ static void ipi_mb(void *info)
static void ipi_rseq(void *info)
{
+ /*
+ * Ensure that all stores done by the calling thread are visible
+ * to the current task before the current task resumes. We could
+ * probably optimize this away on most architectures, but by the
+ * time we've already sent an IPI, the cost of the extra smp_mb()
+ * is negligible.
+ */
+ smp_mb();
rseq_preempt(current);
}
The patch below does not apply to the 5.9-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From c5b58c8c860db330c0b8b891b69014ee9d470dab Mon Sep 17 00:00:00 2001
From: Evan Quan <evan.quan(a)amd.com>
Date: Wed, 9 Dec 2020 16:34:22 +0800
Subject: [PATCH] drm/amd/pm: typo fix (CUSTOM -> COMPUTE)
The "COMPUTE" was wrongly spelled as "CUSTOM".
Signed-off-by: Evan Quan <evan.quan(a)amd.com>
Reviewed-by: Alex Deucher <alexander.deucher(a)amd.com>
Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com>
Cc: stable(a)vger.kernel.org # 5.9.x
diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
index 895d89bea7fa..cf7c4f0e0a0b 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
@@ -217,7 +217,7 @@ static struct cmn2asic_mapping sienna_cichlid_workload_map[PP_SMC_POWER_PROFILE_
WORKLOAD_MAP(PP_SMC_POWER_PROFILE_POWERSAVING, WORKLOAD_PPLIB_POWER_SAVING_BIT),
WORKLOAD_MAP(PP_SMC_POWER_PROFILE_VIDEO, WORKLOAD_PPLIB_VIDEO_BIT),
WORKLOAD_MAP(PP_SMC_POWER_PROFILE_VR, WORKLOAD_PPLIB_VR_BIT),
- WORKLOAD_MAP(PP_SMC_POWER_PROFILE_COMPUTE, WORKLOAD_PPLIB_CUSTOM_BIT),
+ WORKLOAD_MAP(PP_SMC_POWER_PROFILE_COMPUTE, WORKLOAD_PPLIB_COMPUTE_BIT),
WORKLOAD_MAP(PP_SMC_POWER_PROFILE_CUSTOM, WORKLOAD_PPLIB_CUSTOM_BIT),
};
The patch below does not apply to the 5.9-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 157fe68d74c2ad2db438c91af9ed3d3a51de4ed7 Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher(a)amd.com>
Date: Mon, 7 Dec 2020 13:12:29 -0500
Subject: [PATCH] drm/amdgpu: fix size calculation with stolen vga memory
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
If we need to keep the stolen vga memory, make sure it is
at least as big as the legacy vga size.
Acked-by: Christian König <christian.koenig(a)amd.com>
Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com>
Cc: stable(a)vger.kernel.org
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
index 36604d751d62..3e4892b7b7d3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
@@ -499,6 +499,9 @@ void amdgpu_gmc_get_vbios_allocations(struct amdgpu_device *adev)
else
size = amdgpu_gmc_get_vbios_fb_size(adev);
+ if (adev->mman.keep_stolen_vga_memory)
+ size = max(size, (unsigned)AMDGPU_VBIOS_VGA_ALLOCATION);
+
/* set to 0 if the pre-OS buffer uses up most of vram */
if ((adev->gmc.real_vram_size - size) < (8 * 1024 * 1024))
size = 0;