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 202f39039a11402dcbcd5fece8d9fa6be83f49ae
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100703-decorated-bodacious-fa3c@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
202f39039a11 ("NFSD: Fix NFSv4's PUTPUBFH operation")
e78e274eb22d ("NFSD: Avoid clashing function prototypes")
eeadcb757945 ("NFSD: Simplify READ_PLUS")
3fdc54646234 ("NFSD: Reduce amount of struct nfsd4_compoundargs that needs clearing")
103cc1fafee4 ("SUNRPC: Parametrize how much of argsize should be zeroed")
1913cdf56cb5 ("NFSD: Replace boolean fields in struct nfsd4_copy")
87689df69491 ("NFSD: Shrink size of struct nfsd4_copy")
09426ef2a64e ("NFSD: Shrink size of struct nfsd4_copy_notify")
99b002a1fa00 ("NFSD: Clean up nfsd4_encode_readlink()")
c738b218a2e5 ("NFSD: Clean up SPLICE_OK in nfsd4_encode_read()")
0cb4d23ae08c ("NFSD: Fix the behavior of READ near OFFSET_MAX")
555dbf1a9aac ("nfsd: Replace use of rwsem with errseq_t")
f11ad7aa6531 ("NFSD: Fix verifier returned in stable WRITEs")
1e37d0e5bda4 ("NFSD: Fix inconsistent indenting")
474bc334698d ("nfsd: Reduce contention for the nfsd_file nf_rwsem")
eac0b17a77fb ("NFSD add vfs_fsync after async copy is done")
bddfdbcddbe2 ("NFSD: Extract the svcxdr_init_encode() helper")
1fcbd1c9456b ("NFSD: Update the NFSv2 READLINK argument decoder to use struct xdr_stream")
224c1c894e48 ("NFSD: Update READLINK3arg decoder to use struct xdr_stream")
be63bd2ac6bb ("NFSD: Update READ3arg decoder to use struct xdr_stream")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 202f39039a11402dcbcd5fece8d9fa6be83f49ae Mon Sep 17 00:00:00 2001
From: Chuck Lever <chuck.lever(a)oracle.com>
Date: Sun, 11 Aug 2024 13:11:07 -0400
Subject: [PATCH] NFSD: Fix NFSv4's PUTPUBFH operation
According to RFC 8881, all minor versions of NFSv4 support PUTPUBFH.
Replace the XDR decoder for PUTPUBFH with a "noop" since we no
longer want the minorversion check, and PUTPUBFH has no arguments to
decode. (Ideally nfsd4_decode_noop should really be called
nfsd4_decode_void).
PUTPUBFH should now behave just like PUTROOTFH.
Reported-by: Cedric Blancher <cedric.blancher(a)gmail.com>
Fixes: e1a90ebd8b23 ("NFSD: Combine decode operations for v4 and v4.1")
Cc: Dan Shelton <dan.f.shelton(a)gmail.com>
Cc: Roland Mainz <roland.mainz(a)nrubsig.org>
Cc: stable(a)vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever(a)oracle.com>
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 4643fcfb7187..f118921250c3 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1245,14 +1245,6 @@ nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
return nfs_ok;
}
-static __be32
-nfsd4_decode_putpubfh(struct nfsd4_compoundargs *argp, union nfsd4_op_u *p)
-{
- if (argp->minorversion == 0)
- return nfs_ok;
- return nfserr_notsupp;
-}
-
static __be32
nfsd4_decode_read(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
{
@@ -2374,7 +2366,7 @@ static const nfsd4_dec nfsd4_dec_ops[] = {
[OP_OPEN_CONFIRM] = nfsd4_decode_open_confirm,
[OP_OPEN_DOWNGRADE] = nfsd4_decode_open_downgrade,
[OP_PUTFH] = nfsd4_decode_putfh,
- [OP_PUTPUBFH] = nfsd4_decode_putpubfh,
+ [OP_PUTPUBFH] = nfsd4_decode_noop,
[OP_PUTROOTFH] = nfsd4_decode_noop,
[OP_READ] = nfsd4_decode_read,
[OP_READDIR] = nfsd4_decode_readdir,
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 45bb63ed20e02ae146336412889fe5450316a84f
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100729-trident-control-06ad@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..
Possible dependencies:
45bb63ed20e0 ("nfsd: fix delegation_blocked() to block correctly for at least 30 seconds")
b3f255ef6bff ("nfsd: use ktime_get_seconds() for timestamps")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 45bb63ed20e02ae146336412889fe5450316a84f Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb(a)suse.de>
Date: Mon, 9 Sep 2024 15:06:36 +1000
Subject: [PATCH] nfsd: fix delegation_blocked() to block correctly for at
least 30 seconds
The pair of bloom filtered used by delegation_blocked() was intended to
block delegations on given filehandles for between 30 and 60 seconds. A
new filehandle would be recorded in the "new" bit set. That would then
be switch to the "old" bit set between 0 and 30 seconds later, and it
would remain as the "old" bit set for 30 seconds.
Unfortunately the code intended to clear the old bit set once it reached
30 seconds old, preparing it to be the next new bit set, instead cleared
the *new* bit set before switching it to be the old bit set. This means
that the "old" bit set is always empty and delegations are blocked
between 0 and 30 seconds.
This patch updates bd->new before clearing the set with that index,
instead of afterwards.
Reported-by: Olga Kornievskaia <okorniev(a)redhat.com>
Cc: stable(a)vger.kernel.org
Fixes: 6282cd565553 ("NFSD: Don't hand out delegations for 30 seconds after recalling them.")
Signed-off-by: NeilBrown <neilb(a)suse.de>
Reviewed-by: Benjamin Coddington <bcodding(a)redhat.com>
Reviewed-by: Jeff Layton <jlayton(a)kernel.org>
Signed-off-by: Chuck Lever <chuck.lever(a)oracle.com>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index cb5a9ab451c5..ac1859c7cc9d 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1078,7 +1078,8 @@ static void nfs4_free_deleg(struct nfs4_stid *stid)
* When a delegation is recalled, the filehandle is stored in the "new"
* filter.
* Every 30 seconds we swap the filters and clear the "new" one,
- * unless both are empty of course.
+ * unless both are empty of course. This results in delegations for a
+ * given filehandle being blocked for between 30 and 60 seconds.
*
* Each filter is 256 bits. We hash the filehandle to 32bit and use the
* low 3 bytes as hash-table indices.
@@ -1107,9 +1108,9 @@ static int delegation_blocked(struct knfsd_fh *fh)
if (ktime_get_seconds() - bd->swap_time > 30) {
bd->entries -= bd->old_entries;
bd->old_entries = bd->entries;
+ bd->new = 1-bd->new;
memset(bd->set[bd->new], 0,
sizeof(bd->set[0]));
- bd->new = 1-bd->new;
bd->swap_time = ktime_get_seconds();
}
spin_unlock(&blocked_delegations_lock);
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 6b44aa559d6c7f4ea591ef9d2352a7250138d62a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100707-brunch-thumb-0511@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
6b44aa559d6c ("drm/rockchip: vop: clear DMA stop bit on RK3066")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 6b44aa559d6c7f4ea591ef9d2352a7250138d62a Mon Sep 17 00:00:00 2001
From: Val Packett <val(a)packett.cool>
Date: Mon, 24 Jun 2024 17:40:48 -0300
Subject: [PATCH] drm/rockchip: vop: clear DMA stop bit on RK3066
The RK3066 VOP sets a dma_stop bit when it's done scanning out a frame
and needs the driver to acknowledge that by clearing the bit.
Unless we clear it "between" frames, the RGB output only shows noise
instead of the picture. atomic_flush is the place for it that least
affects other code (doing it on vblank would require converting all
other usages of the reg_lock to spin_(un)lock_irq, which would affect
performance for everyone).
This seems to be a redundant synchronization mechanism that was removed
in later iterations of the VOP hardware block.
Fixes: f4a6de855eae ("drm: rockchip: vop: add rk3066 vop definitions")
Cc: stable(a)vger.kernel.org
Signed-off-by: Val Packett <val(a)packett.cool>
Signed-off-by: Heiko Stuebner <heiko(a)sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240624204054.5524-2-val@pac…
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index a13473b2d54c..e88fbd5685a3 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -1583,6 +1583,10 @@ static void vop_crtc_atomic_flush(struct drm_crtc *crtc,
VOP_AFBC_SET(vop, enable, s->enable_afbc);
vop_cfg_done(vop);
+ /* Ack the DMA transfer of the previous frame (RK3066). */
+ if (VOP_HAS_REG(vop, common, dma_stop))
+ VOP_REG_SET(vop, common, dma_stop, 0);
+
spin_unlock(&vop->reg_lock);
/*
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
index b33e5bdc26be..0cf512cc1614 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
@@ -122,6 +122,7 @@ struct vop_common {
struct vop_reg lut_buffer_index;
struct vop_reg gate_en;
struct vop_reg mmu_en;
+ struct vop_reg dma_stop;
struct vop_reg out_mode;
struct vop_reg standby;
};
diff --git a/drivers/gpu/drm/rockchip/rockchip_vop_reg.c b/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
index b9ee02061d5b..9bcb40a640af 100644
--- a/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
+++ b/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
@@ -466,6 +466,7 @@ static const struct vop_output rk3066_output = {
};
static const struct vop_common rk3066_common = {
+ .dma_stop = VOP_REG(RK3066_SYS_CTRL0, 0x1, 0),
.standby = VOP_REG(RK3066_SYS_CTRL0, 0x1, 1),
.out_mode = VOP_REG(RK3066_DSP_CTRL0, 0xf, 0),
.cfg_done = VOP_REG(RK3066_REG_CFG_DONE, 0x1, 0),
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 6b44aa559d6c7f4ea591ef9d2352a7250138d62a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100707-camping-hammock-c18a@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
6b44aa559d6c ("drm/rockchip: vop: clear DMA stop bit on RK3066")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 6b44aa559d6c7f4ea591ef9d2352a7250138d62a Mon Sep 17 00:00:00 2001
From: Val Packett <val(a)packett.cool>
Date: Mon, 24 Jun 2024 17:40:48 -0300
Subject: [PATCH] drm/rockchip: vop: clear DMA stop bit on RK3066
The RK3066 VOP sets a dma_stop bit when it's done scanning out a frame
and needs the driver to acknowledge that by clearing the bit.
Unless we clear it "between" frames, the RGB output only shows noise
instead of the picture. atomic_flush is the place for it that least
affects other code (doing it on vblank would require converting all
other usages of the reg_lock to spin_(un)lock_irq, which would affect
performance for everyone).
This seems to be a redundant synchronization mechanism that was removed
in later iterations of the VOP hardware block.
Fixes: f4a6de855eae ("drm: rockchip: vop: add rk3066 vop definitions")
Cc: stable(a)vger.kernel.org
Signed-off-by: Val Packett <val(a)packett.cool>
Signed-off-by: Heiko Stuebner <heiko(a)sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240624204054.5524-2-val@pac…
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index a13473b2d54c..e88fbd5685a3 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -1583,6 +1583,10 @@ static void vop_crtc_atomic_flush(struct drm_crtc *crtc,
VOP_AFBC_SET(vop, enable, s->enable_afbc);
vop_cfg_done(vop);
+ /* Ack the DMA transfer of the previous frame (RK3066). */
+ if (VOP_HAS_REG(vop, common, dma_stop))
+ VOP_REG_SET(vop, common, dma_stop, 0);
+
spin_unlock(&vop->reg_lock);
/*
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
index b33e5bdc26be..0cf512cc1614 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
@@ -122,6 +122,7 @@ struct vop_common {
struct vop_reg lut_buffer_index;
struct vop_reg gate_en;
struct vop_reg mmu_en;
+ struct vop_reg dma_stop;
struct vop_reg out_mode;
struct vop_reg standby;
};
diff --git a/drivers/gpu/drm/rockchip/rockchip_vop_reg.c b/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
index b9ee02061d5b..9bcb40a640af 100644
--- a/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
+++ b/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
@@ -466,6 +466,7 @@ static const struct vop_output rk3066_output = {
};
static const struct vop_common rk3066_common = {
+ .dma_stop = VOP_REG(RK3066_SYS_CTRL0, 0x1, 0),
.standby = VOP_REG(RK3066_SYS_CTRL0, 0x1, 1),
.out_mode = VOP_REG(RK3066_DSP_CTRL0, 0xf, 0),
.cfg_done = VOP_REG(RK3066_REG_CFG_DONE, 0x1, 0),
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 6b44aa559d6c7f4ea591ef9d2352a7250138d62a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100706-contort-navigator-6ca8@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
6b44aa559d6c ("drm/rockchip: vop: clear DMA stop bit on RK3066")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 6b44aa559d6c7f4ea591ef9d2352a7250138d62a Mon Sep 17 00:00:00 2001
From: Val Packett <val(a)packett.cool>
Date: Mon, 24 Jun 2024 17:40:48 -0300
Subject: [PATCH] drm/rockchip: vop: clear DMA stop bit on RK3066
The RK3066 VOP sets a dma_stop bit when it's done scanning out a frame
and needs the driver to acknowledge that by clearing the bit.
Unless we clear it "between" frames, the RGB output only shows noise
instead of the picture. atomic_flush is the place for it that least
affects other code (doing it on vblank would require converting all
other usages of the reg_lock to spin_(un)lock_irq, which would affect
performance for everyone).
This seems to be a redundant synchronization mechanism that was removed
in later iterations of the VOP hardware block.
Fixes: f4a6de855eae ("drm: rockchip: vop: add rk3066 vop definitions")
Cc: stable(a)vger.kernel.org
Signed-off-by: Val Packett <val(a)packett.cool>
Signed-off-by: Heiko Stuebner <heiko(a)sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240624204054.5524-2-val@pac…
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index a13473b2d54c..e88fbd5685a3 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -1583,6 +1583,10 @@ static void vop_crtc_atomic_flush(struct drm_crtc *crtc,
VOP_AFBC_SET(vop, enable, s->enable_afbc);
vop_cfg_done(vop);
+ /* Ack the DMA transfer of the previous frame (RK3066). */
+ if (VOP_HAS_REG(vop, common, dma_stop))
+ VOP_REG_SET(vop, common, dma_stop, 0);
+
spin_unlock(&vop->reg_lock);
/*
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
index b33e5bdc26be..0cf512cc1614 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
@@ -122,6 +122,7 @@ struct vop_common {
struct vop_reg lut_buffer_index;
struct vop_reg gate_en;
struct vop_reg mmu_en;
+ struct vop_reg dma_stop;
struct vop_reg out_mode;
struct vop_reg standby;
};
diff --git a/drivers/gpu/drm/rockchip/rockchip_vop_reg.c b/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
index b9ee02061d5b..9bcb40a640af 100644
--- a/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
+++ b/drivers/gpu/drm/rockchip/rockchip_vop_reg.c
@@ -466,6 +466,7 @@ static const struct vop_output rk3066_output = {
};
static const struct vop_common rk3066_common = {
+ .dma_stop = VOP_REG(RK3066_SYS_CTRL0, 0x1, 0),
.standby = VOP_REG(RK3066_SYS_CTRL0, 0x1, 1),
.out_mode = VOP_REG(RK3066_DSP_CTRL0, 0xf, 0),
.cfg_done = VOP_REG(RK3066_REG_CFG_DONE, 0x1, 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 3840cbe24cf060ea05a585ca497814609f5d47d1
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100745-barometer-saffron-c873@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
3840cbe24cf0 ("sched: psi: fix bogus pressure spikes from aggregation race")
ddae0ca2a8fe ("sched: Move psi_account_irqtime() out of update_rq_clock_task() hotpath")
0c2924079f5a ("sched/psi: Bail out early from irq time accounting")
a3b2aeac9d15 ("delayacct: track delays from IRQ/SOFTIRQ")
eca7de7cdc38 ("delayacct: improve the average delay precision of getdelay tool to microsecond")
6ab587e8e8b4 ("docs/zh_CN: Update the translation of delay-accounting to 6.1-rc8")
34f26a15611a ("sched/psi: Per-cgroup PSI accounting disable/re-enable interface")
dc86aba751e2 ("sched/psi: Cache parent psi_group to speed up group iteration")
52b1364ba0b1 ("sched/psi: Add PSI_IRQ to track IRQ/SOFTIRQ pressure")
71dbdde7914d ("sched/psi: Remove NR_ONCPU task accounting")
65176f59a18d ("sched/psi: Optimize task switch inside shared cgroups again")
d79ddb069c52 ("sched/psi: Move private helpers to sched/stats.h")
c530a3c716b9 ("sched/psi: Fix periodic aggregation shut off")
5f69a6577bc3 ("psi: dont alloc memory for psi by default")
662ce1dc9caf ("delayacct: track delays from write-protect copy")
6f664045c868 ("Merge tag 'mm-nonmm-stable-2022-05-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3840cbe24cf060ea05a585ca497814609f5d47d1 Mon Sep 17 00:00:00 2001
From: Johannes Weiner <hannes(a)cmpxchg.org>
Date: Thu, 3 Oct 2024 07:29:05 -0400
Subject: [PATCH] sched: psi: fix bogus pressure spikes from aggregation race
Brandon reports sporadic, non-sensical spikes in cumulative pressure
time (total=) when reading cpu.pressure at a high rate. This is due to
a race condition between reader aggregation and tasks changing states.
While it affects all states and all resources captured by PSI, in
practice it most likely triggers with CPU pressure, since scheduling
events are so frequent compared to other resource events.
The race context is the live snooping of ongoing stalls during a
pressure read. The read aggregates per-cpu records for stalls that
have concluded, but will also incorporate ad-hoc the duration of any
active state that hasn't been recorded yet. This is important to get
timely measurements of ongoing stalls. Those ad-hoc samples are
calculated on-the-fly up to the current time on that CPU; since the
stall hasn't concluded, it's expected that this is the minimum amount
of stall time that will enter the per-cpu records once it does.
The problem is that the path that concludes the state uses a CPU clock
read that is not synchronized against aggregators; the clock is read
outside of the seqlock protection. This allows aggregators to race and
snoop a stall with a longer duration than will actually be recorded.
With the recorded stall time being less than the last snapshot
remembered by the aggregator, a subsequent sample will underflow and
observe a bogus delta value, resulting in an erratic jump in pressure.
Fix this by moving the clock read of the state change into the seqlock
protection. This ensures no aggregation can snoop live stalls past the
time that's recorded when the state concludes.
Reported-by: Brandon Duffany <brandon(a)buildbuddy.io>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219194
Link: https://lore.kernel.org/lkml/20240827121851.GB438928@cmpxchg.org/
Fixes: df77430639c9 ("psi: Reduce calls to sched_clock() in psi")
Cc: stable(a)vger.kernel.org
Signed-off-by: Johannes Weiner <hannes(a)cmpxchg.org>
Reviewed-by: Chengming Zhou <chengming.zhou(a)linux.dev>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 020d58967d4e..84dad1511d1e 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -769,12 +769,13 @@ static void record_times(struct psi_group_cpu *groupc, u64 now)
}
static void psi_group_change(struct psi_group *group, int cpu,
- unsigned int clear, unsigned int set, u64 now,
+ unsigned int clear, unsigned int set,
bool wake_clock)
{
struct psi_group_cpu *groupc;
unsigned int t, m;
u32 state_mask;
+ u64 now;
lockdep_assert_rq_held(cpu_rq(cpu));
groupc = per_cpu_ptr(group->pcpu, cpu);
@@ -789,6 +790,7 @@ static void psi_group_change(struct psi_group *group, int cpu,
* SOME and FULL time these may have resulted in.
*/
write_seqcount_begin(&groupc->seq);
+ now = cpu_clock(cpu);
/*
* Start with TSK_ONCPU, which doesn't have a corresponding
@@ -899,18 +901,15 @@ void psi_task_change(struct task_struct *task, int clear, int set)
{
int cpu = task_cpu(task);
struct psi_group *group;
- u64 now;
if (!task->pid)
return;
psi_flags_change(task, clear, set);
- now = cpu_clock(cpu);
-
group = task_psi_group(task);
do {
- psi_group_change(group, cpu, clear, set, now, true);
+ psi_group_change(group, cpu, clear, set, true);
} while ((group = group->parent));
}
@@ -919,7 +918,6 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
{
struct psi_group *group, *common = NULL;
int cpu = task_cpu(prev);
- u64 now = cpu_clock(cpu);
if (next->pid) {
psi_flags_change(next, 0, TSK_ONCPU);
@@ -936,7 +934,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
break;
}
- psi_group_change(group, cpu, 0, TSK_ONCPU, now, true);
+ psi_group_change(group, cpu, 0, TSK_ONCPU, true);
} while ((group = group->parent));
}
@@ -974,7 +972,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
do {
if (group == common)
break;
- psi_group_change(group, cpu, clear, set, now, wake_clock);
+ psi_group_change(group, cpu, clear, set, wake_clock);
} while ((group = group->parent));
/*
@@ -986,7 +984,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
if ((prev->psi_flags ^ next->psi_flags) & ~TSK_ONCPU) {
clear &= ~TSK_ONCPU;
for (; group; group = group->parent)
- psi_group_change(group, cpu, clear, set, now, wake_clock);
+ psi_group_change(group, cpu, clear, set, wake_clock);
}
}
}
@@ -997,8 +995,8 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
int cpu = task_cpu(curr);
struct psi_group *group;
struct psi_group_cpu *groupc;
- u64 now, irq;
s64 delta;
+ u64 irq;
if (static_branch_likely(&psi_disabled))
return;
@@ -1011,7 +1009,6 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
if (prev && task_psi_group(prev) == group)
return;
- now = cpu_clock(cpu);
irq = irq_time_read(cpu);
delta = (s64)(irq - rq->psi_irq_time);
if (delta < 0)
@@ -1019,12 +1016,15 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
rq->psi_irq_time = irq;
do {
+ u64 now;
+
if (!group->enabled)
continue;
groupc = per_cpu_ptr(group->pcpu, cpu);
write_seqcount_begin(&groupc->seq);
+ now = cpu_clock(cpu);
record_times(groupc, now);
groupc->times[PSI_IRQ_FULL] += delta;
@@ -1223,11 +1223,9 @@ void psi_cgroup_restart(struct psi_group *group)
for_each_possible_cpu(cpu) {
struct rq *rq = cpu_rq(cpu);
struct rq_flags rf;
- u64 now;
rq_lock_irq(rq, &rf);
- now = cpu_clock(cpu);
- psi_group_change(group, cpu, 0, 0, now, true);
+ psi_group_change(group, cpu, 0, 0, true);
rq_unlock_irq(rq, &rf);
}
}
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 3840cbe24cf060ea05a585ca497814609f5d47d1
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100744-slurp-uncouple-456c@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
3840cbe24cf0 ("sched: psi: fix bogus pressure spikes from aggregation race")
ddae0ca2a8fe ("sched: Move psi_account_irqtime() out of update_rq_clock_task() hotpath")
0c2924079f5a ("sched/psi: Bail out early from irq time accounting")
a3b2aeac9d15 ("delayacct: track delays from IRQ/SOFTIRQ")
eca7de7cdc38 ("delayacct: improve the average delay precision of getdelay tool to microsecond")
6ab587e8e8b4 ("docs/zh_CN: Update the translation of delay-accounting to 6.1-rc8")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3840cbe24cf060ea05a585ca497814609f5d47d1 Mon Sep 17 00:00:00 2001
From: Johannes Weiner <hannes(a)cmpxchg.org>
Date: Thu, 3 Oct 2024 07:29:05 -0400
Subject: [PATCH] sched: psi: fix bogus pressure spikes from aggregation race
Brandon reports sporadic, non-sensical spikes in cumulative pressure
time (total=) when reading cpu.pressure at a high rate. This is due to
a race condition between reader aggregation and tasks changing states.
While it affects all states and all resources captured by PSI, in
practice it most likely triggers with CPU pressure, since scheduling
events are so frequent compared to other resource events.
The race context is the live snooping of ongoing stalls during a
pressure read. The read aggregates per-cpu records for stalls that
have concluded, but will also incorporate ad-hoc the duration of any
active state that hasn't been recorded yet. This is important to get
timely measurements of ongoing stalls. Those ad-hoc samples are
calculated on-the-fly up to the current time on that CPU; since the
stall hasn't concluded, it's expected that this is the minimum amount
of stall time that will enter the per-cpu records once it does.
The problem is that the path that concludes the state uses a CPU clock
read that is not synchronized against aggregators; the clock is read
outside of the seqlock protection. This allows aggregators to race and
snoop a stall with a longer duration than will actually be recorded.
With the recorded stall time being less than the last snapshot
remembered by the aggregator, a subsequent sample will underflow and
observe a bogus delta value, resulting in an erratic jump in pressure.
Fix this by moving the clock read of the state change into the seqlock
protection. This ensures no aggregation can snoop live stalls past the
time that's recorded when the state concludes.
Reported-by: Brandon Duffany <brandon(a)buildbuddy.io>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219194
Link: https://lore.kernel.org/lkml/20240827121851.GB438928@cmpxchg.org/
Fixes: df77430639c9 ("psi: Reduce calls to sched_clock() in psi")
Cc: stable(a)vger.kernel.org
Signed-off-by: Johannes Weiner <hannes(a)cmpxchg.org>
Reviewed-by: Chengming Zhou <chengming.zhou(a)linux.dev>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 020d58967d4e..84dad1511d1e 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -769,12 +769,13 @@ static void record_times(struct psi_group_cpu *groupc, u64 now)
}
static void psi_group_change(struct psi_group *group, int cpu,
- unsigned int clear, unsigned int set, u64 now,
+ unsigned int clear, unsigned int set,
bool wake_clock)
{
struct psi_group_cpu *groupc;
unsigned int t, m;
u32 state_mask;
+ u64 now;
lockdep_assert_rq_held(cpu_rq(cpu));
groupc = per_cpu_ptr(group->pcpu, cpu);
@@ -789,6 +790,7 @@ static void psi_group_change(struct psi_group *group, int cpu,
* SOME and FULL time these may have resulted in.
*/
write_seqcount_begin(&groupc->seq);
+ now = cpu_clock(cpu);
/*
* Start with TSK_ONCPU, which doesn't have a corresponding
@@ -899,18 +901,15 @@ void psi_task_change(struct task_struct *task, int clear, int set)
{
int cpu = task_cpu(task);
struct psi_group *group;
- u64 now;
if (!task->pid)
return;
psi_flags_change(task, clear, set);
- now = cpu_clock(cpu);
-
group = task_psi_group(task);
do {
- psi_group_change(group, cpu, clear, set, now, true);
+ psi_group_change(group, cpu, clear, set, true);
} while ((group = group->parent));
}
@@ -919,7 +918,6 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
{
struct psi_group *group, *common = NULL;
int cpu = task_cpu(prev);
- u64 now = cpu_clock(cpu);
if (next->pid) {
psi_flags_change(next, 0, TSK_ONCPU);
@@ -936,7 +934,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
break;
}
- psi_group_change(group, cpu, 0, TSK_ONCPU, now, true);
+ psi_group_change(group, cpu, 0, TSK_ONCPU, true);
} while ((group = group->parent));
}
@@ -974,7 +972,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
do {
if (group == common)
break;
- psi_group_change(group, cpu, clear, set, now, wake_clock);
+ psi_group_change(group, cpu, clear, set, wake_clock);
} while ((group = group->parent));
/*
@@ -986,7 +984,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
if ((prev->psi_flags ^ next->psi_flags) & ~TSK_ONCPU) {
clear &= ~TSK_ONCPU;
for (; group; group = group->parent)
- psi_group_change(group, cpu, clear, set, now, wake_clock);
+ psi_group_change(group, cpu, clear, set, wake_clock);
}
}
}
@@ -997,8 +995,8 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
int cpu = task_cpu(curr);
struct psi_group *group;
struct psi_group_cpu *groupc;
- u64 now, irq;
s64 delta;
+ u64 irq;
if (static_branch_likely(&psi_disabled))
return;
@@ -1011,7 +1009,6 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
if (prev && task_psi_group(prev) == group)
return;
- now = cpu_clock(cpu);
irq = irq_time_read(cpu);
delta = (s64)(irq - rq->psi_irq_time);
if (delta < 0)
@@ -1019,12 +1016,15 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
rq->psi_irq_time = irq;
do {
+ u64 now;
+
if (!group->enabled)
continue;
groupc = per_cpu_ptr(group->pcpu, cpu);
write_seqcount_begin(&groupc->seq);
+ now = cpu_clock(cpu);
record_times(groupc, now);
groupc->times[PSI_IRQ_FULL] += delta;
@@ -1223,11 +1223,9 @@ void psi_cgroup_restart(struct psi_group *group)
for_each_possible_cpu(cpu) {
struct rq *rq = cpu_rq(cpu);
struct rq_flags rf;
- u64 now;
rq_lock_irq(rq, &rf);
- now = cpu_clock(cpu);
- psi_group_change(group, cpu, 0, 0, now, true);
+ psi_group_change(group, cpu, 0, 0, true);
rq_unlock_irq(rq, &rf);
}
}
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 3840cbe24cf060ea05a585ca497814609f5d47d1
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100743-charity-wannabe-8c03@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
3840cbe24cf0 ("sched: psi: fix bogus pressure spikes from aggregation race")
ddae0ca2a8fe ("sched: Move psi_account_irqtime() out of update_rq_clock_task() hotpath")
0c2924079f5a ("sched/psi: Bail out early from irq time accounting")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3840cbe24cf060ea05a585ca497814609f5d47d1 Mon Sep 17 00:00:00 2001
From: Johannes Weiner <hannes(a)cmpxchg.org>
Date: Thu, 3 Oct 2024 07:29:05 -0400
Subject: [PATCH] sched: psi: fix bogus pressure spikes from aggregation race
Brandon reports sporadic, non-sensical spikes in cumulative pressure
time (total=) when reading cpu.pressure at a high rate. This is due to
a race condition between reader aggregation and tasks changing states.
While it affects all states and all resources captured by PSI, in
practice it most likely triggers with CPU pressure, since scheduling
events are so frequent compared to other resource events.
The race context is the live snooping of ongoing stalls during a
pressure read. The read aggregates per-cpu records for stalls that
have concluded, but will also incorporate ad-hoc the duration of any
active state that hasn't been recorded yet. This is important to get
timely measurements of ongoing stalls. Those ad-hoc samples are
calculated on-the-fly up to the current time on that CPU; since the
stall hasn't concluded, it's expected that this is the minimum amount
of stall time that will enter the per-cpu records once it does.
The problem is that the path that concludes the state uses a CPU clock
read that is not synchronized against aggregators; the clock is read
outside of the seqlock protection. This allows aggregators to race and
snoop a stall with a longer duration than will actually be recorded.
With the recorded stall time being less than the last snapshot
remembered by the aggregator, a subsequent sample will underflow and
observe a bogus delta value, resulting in an erratic jump in pressure.
Fix this by moving the clock read of the state change into the seqlock
protection. This ensures no aggregation can snoop live stalls past the
time that's recorded when the state concludes.
Reported-by: Brandon Duffany <brandon(a)buildbuddy.io>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219194
Link: https://lore.kernel.org/lkml/20240827121851.GB438928@cmpxchg.org/
Fixes: df77430639c9 ("psi: Reduce calls to sched_clock() in psi")
Cc: stable(a)vger.kernel.org
Signed-off-by: Johannes Weiner <hannes(a)cmpxchg.org>
Reviewed-by: Chengming Zhou <chengming.zhou(a)linux.dev>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 020d58967d4e..84dad1511d1e 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -769,12 +769,13 @@ static void record_times(struct psi_group_cpu *groupc, u64 now)
}
static void psi_group_change(struct psi_group *group, int cpu,
- unsigned int clear, unsigned int set, u64 now,
+ unsigned int clear, unsigned int set,
bool wake_clock)
{
struct psi_group_cpu *groupc;
unsigned int t, m;
u32 state_mask;
+ u64 now;
lockdep_assert_rq_held(cpu_rq(cpu));
groupc = per_cpu_ptr(group->pcpu, cpu);
@@ -789,6 +790,7 @@ static void psi_group_change(struct psi_group *group, int cpu,
* SOME and FULL time these may have resulted in.
*/
write_seqcount_begin(&groupc->seq);
+ now = cpu_clock(cpu);
/*
* Start with TSK_ONCPU, which doesn't have a corresponding
@@ -899,18 +901,15 @@ void psi_task_change(struct task_struct *task, int clear, int set)
{
int cpu = task_cpu(task);
struct psi_group *group;
- u64 now;
if (!task->pid)
return;
psi_flags_change(task, clear, set);
- now = cpu_clock(cpu);
-
group = task_psi_group(task);
do {
- psi_group_change(group, cpu, clear, set, now, true);
+ psi_group_change(group, cpu, clear, set, true);
} while ((group = group->parent));
}
@@ -919,7 +918,6 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
{
struct psi_group *group, *common = NULL;
int cpu = task_cpu(prev);
- u64 now = cpu_clock(cpu);
if (next->pid) {
psi_flags_change(next, 0, TSK_ONCPU);
@@ -936,7 +934,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
break;
}
- psi_group_change(group, cpu, 0, TSK_ONCPU, now, true);
+ psi_group_change(group, cpu, 0, TSK_ONCPU, true);
} while ((group = group->parent));
}
@@ -974,7 +972,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
do {
if (group == common)
break;
- psi_group_change(group, cpu, clear, set, now, wake_clock);
+ psi_group_change(group, cpu, clear, set, wake_clock);
} while ((group = group->parent));
/*
@@ -986,7 +984,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
if ((prev->psi_flags ^ next->psi_flags) & ~TSK_ONCPU) {
clear &= ~TSK_ONCPU;
for (; group; group = group->parent)
- psi_group_change(group, cpu, clear, set, now, wake_clock);
+ psi_group_change(group, cpu, clear, set, wake_clock);
}
}
}
@@ -997,8 +995,8 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
int cpu = task_cpu(curr);
struct psi_group *group;
struct psi_group_cpu *groupc;
- u64 now, irq;
s64 delta;
+ u64 irq;
if (static_branch_likely(&psi_disabled))
return;
@@ -1011,7 +1009,6 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
if (prev && task_psi_group(prev) == group)
return;
- now = cpu_clock(cpu);
irq = irq_time_read(cpu);
delta = (s64)(irq - rq->psi_irq_time);
if (delta < 0)
@@ -1019,12 +1016,15 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
rq->psi_irq_time = irq;
do {
+ u64 now;
+
if (!group->enabled)
continue;
groupc = per_cpu_ptr(group->pcpu, cpu);
write_seqcount_begin(&groupc->seq);
+ now = cpu_clock(cpu);
record_times(groupc, now);
groupc->times[PSI_IRQ_FULL] += delta;
@@ -1223,11 +1223,9 @@ void psi_cgroup_restart(struct psi_group *group)
for_each_possible_cpu(cpu) {
struct rq *rq = cpu_rq(cpu);
struct rq_flags rf;
- u64 now;
rq_lock_irq(rq, &rf);
- now = cpu_clock(cpu);
- psi_group_change(group, cpu, 0, 0, now, true);
+ psi_group_change(group, cpu, 0, 0, true);
rq_unlock_irq(rq, &rf);
}
}
The patch below does not apply to the 6.10-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-6.10.y
git checkout FETCH_HEAD
git cherry-pick -x 3840cbe24cf060ea05a585ca497814609f5d47d1
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100742-manual-outright-b57d@gregkh' --subject-prefix 'PATCH 6.10.y' HEAD^..
Possible dependencies:
3840cbe24cf0 ("sched: psi: fix bogus pressure spikes from aggregation race")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3840cbe24cf060ea05a585ca497814609f5d47d1 Mon Sep 17 00:00:00 2001
From: Johannes Weiner <hannes(a)cmpxchg.org>
Date: Thu, 3 Oct 2024 07:29:05 -0400
Subject: [PATCH] sched: psi: fix bogus pressure spikes from aggregation race
Brandon reports sporadic, non-sensical spikes in cumulative pressure
time (total=) when reading cpu.pressure at a high rate. This is due to
a race condition between reader aggregation and tasks changing states.
While it affects all states and all resources captured by PSI, in
practice it most likely triggers with CPU pressure, since scheduling
events are so frequent compared to other resource events.
The race context is the live snooping of ongoing stalls during a
pressure read. The read aggregates per-cpu records for stalls that
have concluded, but will also incorporate ad-hoc the duration of any
active state that hasn't been recorded yet. This is important to get
timely measurements of ongoing stalls. Those ad-hoc samples are
calculated on-the-fly up to the current time on that CPU; since the
stall hasn't concluded, it's expected that this is the minimum amount
of stall time that will enter the per-cpu records once it does.
The problem is that the path that concludes the state uses a CPU clock
read that is not synchronized against aggregators; the clock is read
outside of the seqlock protection. This allows aggregators to race and
snoop a stall with a longer duration than will actually be recorded.
With the recorded stall time being less than the last snapshot
remembered by the aggregator, a subsequent sample will underflow and
observe a bogus delta value, resulting in an erratic jump in pressure.
Fix this by moving the clock read of the state change into the seqlock
protection. This ensures no aggregation can snoop live stalls past the
time that's recorded when the state concludes.
Reported-by: Brandon Duffany <brandon(a)buildbuddy.io>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219194
Link: https://lore.kernel.org/lkml/20240827121851.GB438928@cmpxchg.org/
Fixes: df77430639c9 ("psi: Reduce calls to sched_clock() in psi")
Cc: stable(a)vger.kernel.org
Signed-off-by: Johannes Weiner <hannes(a)cmpxchg.org>
Reviewed-by: Chengming Zhou <chengming.zhou(a)linux.dev>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 020d58967d4e..84dad1511d1e 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -769,12 +769,13 @@ static void record_times(struct psi_group_cpu *groupc, u64 now)
}
static void psi_group_change(struct psi_group *group, int cpu,
- unsigned int clear, unsigned int set, u64 now,
+ unsigned int clear, unsigned int set,
bool wake_clock)
{
struct psi_group_cpu *groupc;
unsigned int t, m;
u32 state_mask;
+ u64 now;
lockdep_assert_rq_held(cpu_rq(cpu));
groupc = per_cpu_ptr(group->pcpu, cpu);
@@ -789,6 +790,7 @@ static void psi_group_change(struct psi_group *group, int cpu,
* SOME and FULL time these may have resulted in.
*/
write_seqcount_begin(&groupc->seq);
+ now = cpu_clock(cpu);
/*
* Start with TSK_ONCPU, which doesn't have a corresponding
@@ -899,18 +901,15 @@ void psi_task_change(struct task_struct *task, int clear, int set)
{
int cpu = task_cpu(task);
struct psi_group *group;
- u64 now;
if (!task->pid)
return;
psi_flags_change(task, clear, set);
- now = cpu_clock(cpu);
-
group = task_psi_group(task);
do {
- psi_group_change(group, cpu, clear, set, now, true);
+ psi_group_change(group, cpu, clear, set, true);
} while ((group = group->parent));
}
@@ -919,7 +918,6 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
{
struct psi_group *group, *common = NULL;
int cpu = task_cpu(prev);
- u64 now = cpu_clock(cpu);
if (next->pid) {
psi_flags_change(next, 0, TSK_ONCPU);
@@ -936,7 +934,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
break;
}
- psi_group_change(group, cpu, 0, TSK_ONCPU, now, true);
+ psi_group_change(group, cpu, 0, TSK_ONCPU, true);
} while ((group = group->parent));
}
@@ -974,7 +972,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
do {
if (group == common)
break;
- psi_group_change(group, cpu, clear, set, now, wake_clock);
+ psi_group_change(group, cpu, clear, set, wake_clock);
} while ((group = group->parent));
/*
@@ -986,7 +984,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next,
if ((prev->psi_flags ^ next->psi_flags) & ~TSK_ONCPU) {
clear &= ~TSK_ONCPU;
for (; group; group = group->parent)
- psi_group_change(group, cpu, clear, set, now, wake_clock);
+ psi_group_change(group, cpu, clear, set, wake_clock);
}
}
}
@@ -997,8 +995,8 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
int cpu = task_cpu(curr);
struct psi_group *group;
struct psi_group_cpu *groupc;
- u64 now, irq;
s64 delta;
+ u64 irq;
if (static_branch_likely(&psi_disabled))
return;
@@ -1011,7 +1009,6 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
if (prev && task_psi_group(prev) == group)
return;
- now = cpu_clock(cpu);
irq = irq_time_read(cpu);
delta = (s64)(irq - rq->psi_irq_time);
if (delta < 0)
@@ -1019,12 +1016,15 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st
rq->psi_irq_time = irq;
do {
+ u64 now;
+
if (!group->enabled)
continue;
groupc = per_cpu_ptr(group->pcpu, cpu);
write_seqcount_begin(&groupc->seq);
+ now = cpu_clock(cpu);
record_times(groupc, now);
groupc->times[PSI_IRQ_FULL] += delta;
@@ -1223,11 +1223,9 @@ void psi_cgroup_restart(struct psi_group *group)
for_each_possible_cpu(cpu) {
struct rq *rq = cpu_rq(cpu);
struct rq_flags rf;
- u64 now;
rq_lock_irq(rq, &rf);
- now = cpu_clock(cpu);
- psi_group_change(group, cpu, 0, 0, now, true);
+ psi_group_change(group, cpu, 0, 0, true);
rq_unlock_irq(rq, &rf);
}
}
The patch below does not apply to the 6.10-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-6.10.y
git checkout FETCH_HEAD
git cherry-pick -x 2d2be279f1ca9e7288282d4214f16eea8a727cdb
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100727-lego-panther-fea9@gregkh' --subject-prefix 'PATCH 6.10.y' HEAD^..
Possible dependencies:
2d2be279f1ca ("drm/xe: fix UAF around queue destruction")
3f371a98dead ("drm/xe: Delete unused GuC submission_state.suspend")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 2d2be279f1ca9e7288282d4214f16eea8a727cdb Mon Sep 17 00:00:00 2001
From: Matthew Auld <matthew.auld(a)intel.com>
Date: Mon, 23 Sep 2024 15:56:48 +0100
Subject: [PATCH] drm/xe: fix UAF around queue destruction
We currently do stuff like queuing the final destruction step on a
random system wq, which will outlive the driver instance. With bad
timing we can teardown the driver with one or more work workqueue still
being alive leading to various UAF splats. Add a fini step to ensure
user queues are properly torn down. At this point GuC should already be
nuked so queue itself should no longer be referenced from hw pov.
v2 (Matt B)
- Looks much safer to use a waitqueue and then just wait for the
xa_array to become empty before triggering the drain.
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2317
Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Signed-off-by: Matthew Auld <matthew.auld(a)intel.com>
Cc: Matthew Brost <matthew.brost(a)intel.com>
Cc: <stable(a)vger.kernel.org> # v6.8+
Reviewed-by: Matthew Brost <matthew.brost(a)intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240923145647.77707-2-matthe…
(cherry picked from commit 861108666cc0e999cffeab6aff17b662e68774e3)
Signed-off-by: Lucas De Marchi <lucas.demarchi(a)intel.com>
diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
index 70d4e4d46c3c..74e593caf87c 100644
--- a/drivers/gpu/drm/xe/xe_device.c
+++ b/drivers/gpu/drm/xe/xe_device.c
@@ -298,6 +298,9 @@ static void xe_device_destroy(struct drm_device *dev, void *dummy)
if (xe->unordered_wq)
destroy_workqueue(xe->unordered_wq);
+ if (xe->destroy_wq)
+ destroy_workqueue(xe->destroy_wq);
+
ttm_device_fini(&xe->ttm);
}
@@ -363,8 +366,9 @@ struct xe_device *xe_device_create(struct pci_dev *pdev,
xe->preempt_fence_wq = alloc_ordered_workqueue("xe-preempt-fence-wq", 0);
xe->ordered_wq = alloc_ordered_workqueue("xe-ordered-wq", 0);
xe->unordered_wq = alloc_workqueue("xe-unordered-wq", 0, 0);
+ xe->destroy_wq = alloc_workqueue("xe-destroy-wq", 0, 0);
if (!xe->ordered_wq || !xe->unordered_wq ||
- !xe->preempt_fence_wq) {
+ !xe->preempt_fence_wq || !xe->destroy_wq) {
/*
* Cleanup done in xe_device_destroy via
* drmm_add_action_or_reset register above
diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
index ec7eb7811126..24c8c2d20676 100644
--- a/drivers/gpu/drm/xe/xe_device_types.h
+++ b/drivers/gpu/drm/xe/xe_device_types.h
@@ -396,6 +396,9 @@ struct xe_device {
/** @unordered_wq: used to serialize unordered work, mostly display */
struct workqueue_struct *unordered_wq;
+ /** @destroy_wq: used to serialize user destroy work, like queue */
+ struct workqueue_struct *destroy_wq;
+
/** @tiles: device tiles */
struct xe_tile tiles[XE_MAX_TILES_PER_DEVICE];
diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
index 715c761dc7d6..98a6a385a796 100644
--- a/drivers/gpu/drm/xe/xe_guc_submit.c
+++ b/drivers/gpu/drm/xe/xe_guc_submit.c
@@ -276,10 +276,26 @@ static struct workqueue_struct *get_submit_wq(struct xe_guc *guc)
}
#endif
+static void xe_guc_submit_fini(struct xe_guc *guc)
+{
+ struct xe_device *xe = guc_to_xe(guc);
+ struct xe_gt *gt = guc_to_gt(guc);
+ int ret;
+
+ ret = wait_event_timeout(guc->submission_state.fini_wq,
+ xa_empty(&guc->submission_state.exec_queue_lookup),
+ HZ * 5);
+
+ drain_workqueue(xe->destroy_wq);
+
+ xe_gt_assert(gt, ret);
+}
+
static void guc_submit_fini(struct drm_device *drm, void *arg)
{
struct xe_guc *guc = arg;
+ xe_guc_submit_fini(guc);
xa_destroy(&guc->submission_state.exec_queue_lookup);
free_submit_wq(guc);
}
@@ -351,6 +367,8 @@ int xe_guc_submit_init(struct xe_guc *guc, unsigned int num_ids)
xa_init(&guc->submission_state.exec_queue_lookup);
+ init_waitqueue_head(&guc->submission_state.fini_wq);
+
primelockdep(guc);
return drmm_add_action_or_reset(&xe->drm, guc_submit_fini, guc);
@@ -367,6 +385,9 @@ static void __release_guc_id(struct xe_guc *guc, struct xe_exec_queue *q, u32 xa
xe_guc_id_mgr_release_locked(&guc->submission_state.idm,
q->guc->id, q->width);
+
+ if (xa_empty(&guc->submission_state.exec_queue_lookup))
+ wake_up(&guc->submission_state.fini_wq);
}
static int alloc_guc_id(struct xe_guc *guc, struct xe_exec_queue *q)
@@ -1274,13 +1295,16 @@ static void __guc_exec_queue_fini_async(struct work_struct *w)
static void guc_exec_queue_fini_async(struct xe_exec_queue *q)
{
+ struct xe_guc *guc = exec_queue_to_guc(q);
+ struct xe_device *xe = guc_to_xe(guc);
+
INIT_WORK(&q->guc->fini_async, __guc_exec_queue_fini_async);
/* We must block on kernel engines so slabs are empty on driver unload */
if (q->flags & EXEC_QUEUE_FLAG_PERMANENT || exec_queue_wedged(q))
__guc_exec_queue_fini_async(&q->guc->fini_async);
else
- queue_work(system_wq, &q->guc->fini_async);
+ queue_work(xe->destroy_wq, &q->guc->fini_async);
}
static void __guc_exec_queue_fini(struct xe_guc *guc, struct xe_exec_queue *q)
diff --git a/drivers/gpu/drm/xe/xe_guc_types.h b/drivers/gpu/drm/xe/xe_guc_types.h
index 546ac6350a31..69046f698271 100644
--- a/drivers/gpu/drm/xe/xe_guc_types.h
+++ b/drivers/gpu/drm/xe/xe_guc_types.h
@@ -81,6 +81,8 @@ struct xe_guc {
#endif
/** @submission_state.enabled: submission is enabled */
bool enabled;
+ /** @submission_state.fini_wq: submit fini wait queue */
+ wait_queue_head_t fini_wq;
} submission_state;
/** @hwconfig: Hardware config state */
struct {