--- /dev/null
+From foo@baz Fri Jan 15 10:47:48 AM CET 2021
+From: Chris Wilson <chris@chris-wilson.co.uk>
+Date: Wed, 16 Dec 2020 09:29:51 +0000
+Subject: drm/i915: Fix mismatch between misplaced vma check and vma insert
+
+From: Chris Wilson <chris@chris-wilson.co.uk>
+
+commit 0e53656ad8abc99e0a80c3de611e593ebbf55829 upstream
+
+When inserting a VMA, we restrict the placement to the low 4G unless the
+caller opts into using the full range. This was done to allow usersapce
+the opportunity to transition slowly from a 32b address space, and to
+avoid breaking inherent 32b assumptions of some commands.
+
+However, for insert we limited ourselves to 4G-4K, but on verification
+we allowed the full 4G. This causes some attempts to bind a new buffer
+to sporadically fail with -ENOSPC, but at other times be bound
+successfully.
+
+commit 48ea1e32c39d ("drm/i915/gen9: Set PIN_ZONE_4G end to 4GB - 1
+page") suggests that there is a genuine problem with stateless addressing
+that cannot utilize the last page in 4G and so we purposefully excluded
+it. This means that the quick pin pass may cause us to utilize a buggy
+placement.
+
+Reported-by: CQ Tang <cq.tang@intel.com>
+Testcase: igt/gem_exec_params/larger-than-life-batch
+Fixes: 48ea1e32c39d ("drm/i915/gen9: Set PIN_ZONE_4G end to 4GB - 1 page")
+Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
+Cc: CQ Tang <cq.tang@intel.com>
+Reviewed-by: CQ Tang <cq.tang@intel.com>
+Reviewed-by: Matthew Auld <matthew.auld@intel.com>
+Cc: <stable@vger.kernel.org> # v4.5+
+Link: https://patchwork.freedesktop.org/patch/msgid/20201216092951.7124-1-chris@chris-wilson.co.uk
+(cherry picked from commit 5f22cc0b134ab702d7f64b714e26018f7288ffee)
+Signed-off-by: Jani Nikula <jani.nikula@intel.com>
+[sudip: use file from old path]
+Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/i915/i915_gem_execbuffer.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
++++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+@@ -380,7 +380,7 @@ eb_vma_misplaced(const struct drm_i915_g
+ return true;
+
+ if (!(flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS) &&
+- (vma->node.start + vma->node.size - 1) >> 32)
++ (vma->node.start + vma->node.size + 4095) >> 32)
+ return true;
+
+ if (flags & __EXEC_OBJECT_NEEDS_MAP &&
--- /dev/null
+From 37309f47e2f5674f3e86cb765312ace42cfcedf5 Mon Sep 17 00:00:00 2001
+From: Ping Cheng <pinglinux@gmail.com>
+Date: Wed, 9 Dec 2020 20:52:30 -0800
+Subject: HID: wacom: Fix memory leakage caused by kfifo_alloc
+
+From: Ping Cheng <pinglinux@gmail.com>
+
+commit 37309f47e2f5674f3e86cb765312ace42cfcedf5 upstream.
+
+As reported by syzbot below, kfifo_alloc'd memory would not be freed
+if a non-zero return value is triggered in wacom_probe. This patch
+creates and uses devm_kfifo_alloc to allocate and free itself.
+
+BUG: memory leak
+unreferenced object 0xffff88810dc44a00 (size 512):
+ comm "kworker/1:2", pid 3674, jiffies 4294943617 (age 14.100s)
+ hex dump (first 32 bytes):
+ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
+ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
+ backtrace:
+ [<0000000023e1afac>] kmalloc_array include/linux/slab.h:592 [inline]
+ [<0000000023e1afac>] __kfifo_alloc+0xad/0x100 lib/kfifo.c:43
+ [<00000000c477f737>] wacom_probe+0x1a1/0x3b0 drivers/hid/wacom_sys.c:2727
+ [<00000000b3109aca>] hid_device_probe+0x16b/0x210 drivers/hid/hid-core.c:2281
+ [<00000000aff7c640>] really_probe+0x159/0x480 drivers/base/dd.c:554
+ [<00000000778d0bc3>] driver_probe_device+0x84/0x100 drivers/base/dd.c:738
+ [<000000005108dbb5>] __device_attach_driver+0xee/0x110 drivers/base/dd.c:844
+ [<00000000efb7c59e>] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:431
+ [<0000000024ab1590>] __device_attach+0x122/0x250 drivers/base/dd.c:912
+ [<000000004c7ac048>] bus_probe_device+0xc6/0xe0 drivers/base/bus.c:491
+ [<00000000b93050a3>] device_add+0x5ac/0xc30 drivers/base/core.c:2936
+ [<00000000e5b46ea5>] hid_add_device+0x151/0x390 drivers/hid/hid-core.c:2437
+ [<00000000c6add147>] usbhid_probe+0x412/0x560 drivers/hid/usbhid/hid-core.c:1407
+ [<00000000c33acdb4>] usb_probe_interface+0x177/0x370 drivers/usb/core/driver.c:396
+ [<00000000aff7c640>] really_probe+0x159/0x480 drivers/base/dd.c:554
+ [<00000000778d0bc3>] driver_probe_device+0x84/0x100 drivers/base/dd.c:738
+ [<000000005108dbb5>] __device_attach_driver+0xee/0x110 drivers/base/dd.c:844
+
+https://syzkaller.appspot.com/bug?extid=5b49c9695968d7250a26
+
+Reported-by: syzbot+5b49c9695968d7250a26@syzkaller.appspotmail.com
+Signed-off-by: Ping Cheng <ping.cheng@wacom.com>
+Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
+Signed-off-by: Jiri Kosina <jkosina@suse.cz>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/hid/wacom_sys.c | 35 ++++++++++++++++++++++++++++++++---
+ 1 file changed, 32 insertions(+), 3 deletions(-)
+
+--- a/drivers/hid/wacom_sys.c
++++ b/drivers/hid/wacom_sys.c
+@@ -1241,6 +1241,37 @@ static int wacom_devm_sysfs_create_group
+ group);
+ }
+
++static void wacom_devm_kfifo_release(struct device *dev, void *res)
++{
++ struct kfifo_rec_ptr_2 *devres = res;
++
++ kfifo_free(devres);
++}
++
++static int wacom_devm_kfifo_alloc(struct wacom *wacom)
++{
++ struct wacom_wac *wacom_wac = &wacom->wacom_wac;
++ struct kfifo_rec_ptr_2 *pen_fifo = &wacom_wac->pen_fifo;
++ int error;
++
++ pen_fifo = devres_alloc(wacom_devm_kfifo_release,
++ sizeof(struct kfifo_rec_ptr_2),
++ GFP_KERNEL);
++
++ if (!pen_fifo)
++ return -ENOMEM;
++
++ error = kfifo_alloc(pen_fifo, WACOM_PKGLEN_MAX, GFP_KERNEL);
++ if (error) {
++ devres_free(pen_fifo);
++ return error;
++ }
++
++ devres_add(&wacom->hdev->dev, pen_fifo);
++
++ return 0;
++}
++
+ enum led_brightness wacom_leds_brightness_get(struct wacom_led *led)
+ {
+ struct wacom *wacom = led->wacom;
+@@ -2697,7 +2728,7 @@ static int wacom_probe(struct hid_device
+ goto fail;
+ }
+
+- error = kfifo_alloc(&wacom_wac->pen_fifo, WACOM_PKGLEN_MAX, GFP_KERNEL);
++ error = wacom_devm_kfifo_alloc(wacom);
+ if (error)
+ goto fail;
+
+@@ -2764,8 +2795,6 @@ static void wacom_remove(struct hid_devi
+ if (wacom->wacom_wac.features.type != REMOTE)
+ wacom_release_resources(wacom);
+
+- kfifo_free(&wacom_wac->pen_fifo);
+-
+ hid_set_drvdata(hdev, NULL);
+ }
+
--- /dev/null
+From foo@baz Fri Jan 15 10:52:25 AM CET 2021
+From: Lorenzo Bianconi <lorenzo@kernel.org>
+Date: Sat, 14 Nov 2020 19:39:05 +0100
+Subject: iio: imu: st_lsm6dsx: fix edge-trigger interrupts
+
+From: Lorenzo Bianconi <lorenzo@kernel.org>
+
+commit 3f9bce7a22a3f8ac9d885c9d75bc45569f24ac8b upstream
+
+If we are using edge IRQs, new samples can arrive while processing
+current interrupt since there are no hw guarantees the irq line
+stays "low" long enough to properly detect the new interrupt.
+In this case the new sample will be missed.
+Polling FIFO status register in st_lsm6dsx_handler_thread routine
+allow us to read new samples even if the interrupt arrives while
+processing previous data and the timeslot where the line is "low"
+is too short to be properly detected.
+
+Fixes: 89ca88a7cdf2 ("iio: imu: st_lsm6dsx: support active-low interrupts")
+Fixes: 290a6ce11d93 ("iio: imu: add support to lsm6dsx driver")
+Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
+Link: https://lore.kernel.org/r/5e93cda7dc1e665f5685c53ad8e9ea71dbae782d.1605378871.git.lorenzo@kernel.org
+Cc: <Stable@vger.kernel.org>
+Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
+[sudip: manual backport to old irq handler path]
+Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c | 26 ++++++++++++++++++++-----
+ 1 file changed, 21 insertions(+), 5 deletions(-)
+
+--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
++++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
+@@ -475,13 +475,29 @@ static irqreturn_t st_lsm6dsx_handler_ir
+ static irqreturn_t st_lsm6dsx_handler_thread(int irq, void *private)
+ {
+ struct st_lsm6dsx_hw *hw = private;
+- int count;
++ int fifo_len = 0, len;
+
+- mutex_lock(&hw->fifo_lock);
+- count = st_lsm6dsx_read_fifo(hw);
+- mutex_unlock(&hw->fifo_lock);
++ /*
++ * If we are using edge IRQs, new samples can arrive while
++ * processing current interrupt since there are no hw
++ * guarantees the irq line stays "low" long enough to properly
++ * detect the new interrupt. In this case the new sample will
++ * be missed.
++ * Polling FIFO status register allow us to read new
++ * samples even if the interrupt arrives while processing
++ * previous data and the timeslot where the line is "low" is
++ * too short to be properly detected.
++ */
++ do {
++ mutex_lock(&hw->fifo_lock);
++ len = st_lsm6dsx_read_fifo(hw);
++ mutex_unlock(&hw->fifo_lock);
+
+- return count ? IRQ_HANDLED : IRQ_NONE;
++ if (len > 0)
++ fifo_len += len;
++ } while (len > 0);
++
++ return fifo_len ? IRQ_HANDLED : IRQ_NONE;
+ }
+
+ static int st_lsm6dsx_buffer_preenable(struct iio_dev *iio_dev)
--- /dev/null
+From foo@baz Fri Jan 15 10:52:16 AM CET 2021
+From: Sean Nyekjaer <sean@geanix.com>
+Date: Mon, 15 Jul 2019 09:07:15 +0200
+Subject: iio: imu: st_lsm6dsx: flip irq return logic
+
+From: Sean Nyekjaer <sean@geanix.com>
+
+commit ec76d918f23034f9f662539ca9c64e2ae3ba9fba upstream
+
+No need for using reverse logic in the irq return,
+fix this by flip things around.
+
+Signed-off-by: Sean Nyekjaer <sean@geanix.com>
+Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
+Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
++++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
+@@ -481,7 +481,7 @@ static irqreturn_t st_lsm6dsx_handler_th
+ count = st_lsm6dsx_read_fifo(hw);
+ mutex_unlock(&hw->fifo_lock);
+
+- return !count ? IRQ_NONE : IRQ_HANDLED;
++ return count ? IRQ_HANDLED : IRQ_NONE;
+ }
+
+ static int st_lsm6dsx_buffer_preenable(struct iio_dev *iio_dev)
chtls-replace-skb_dequeue-with-skb_peek.patch
chtls-added-a-check-to-avoid-null-pointer-dereference.patch
chtls-fix-chtls-resources-release-sequence.patch
+x86-resctrl-use-an-ipi-instead-of-task_work_add-to-update-pqr_assoc-msr.patch
+x86-resctrl-don-t-move-a-task-to-the-same-resource-group.patch
+vmlinux.lds.h-add-pgo-and-autofdo-input-sections.patch
+drm-i915-fix-mismatch-between-misplaced-vma-check-and-vma-insert.patch
+spi-pxa2xx-fix-use-after-free-on-unbind.patch
+iio-imu-st_lsm6dsx-flip-irq-return-logic.patch
+iio-imu-st_lsm6dsx-fix-edge-trigger-interrupts.patch
+hid-wacom-fix-memory-leakage-caused-by-kfifo_alloc.patch
--- /dev/null
+From foo@baz Fri Jan 15 10:50:39 AM CET 2021
+From: Lukas Wunner <lukas@wunner.de>
+Date: Mon, 7 Dec 2020 09:17:05 +0100
+Subject: spi: pxa2xx: Fix use-after-free on unbind
+
+From: Lukas Wunner <lukas@wunner.de>
+
+commit 5626308bb94d9f930aa5f7c77327df4c6daa7759 upstream
+
+pxa2xx_spi_remove() accesses the driver's private data after calling
+spi_unregister_controller() even though that function releases the last
+reference on the spi_controller and thereby frees the private data.
+
+Fix by switching over to the new devm_spi_alloc_master/slave() helper
+which keeps the private data accessible until the driver has unbound.
+
+Fixes: 32e5b57232c0 ("spi: pxa2xx: Fix controller unregister order")
+Signed-off-by: Lukas Wunner <lukas@wunner.de>
+Cc: <stable@vger.kernel.org> # v2.6.17+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation
+Cc: <stable@vger.kernel.org> # v2.6.17+: 32e5b57232c0: spi: pxa2xx: Fix controller unregister order
+Cc: <stable@vger.kernel.org> # v2.6.17+
+Link: https://lore.kernel.org/r/5764b04d4a6e43069ebb7808f64c2f774ac6f193.1607286887.git.lukas@wunner.de
+Signed-off-by: Mark Brown <broonie@kernel.org>
+[sudip: adjust context]
+Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/spi/spi-pxa2xx.c | 3 +--
+ 1 file changed, 1 insertion(+), 2 deletions(-)
+
+--- a/drivers/spi/spi-pxa2xx.c
++++ b/drivers/spi/spi-pxa2xx.c
+@@ -1572,7 +1572,7 @@ static int pxa2xx_spi_probe(struct platf
+ return -ENODEV;
+ }
+
+- master = spi_alloc_master(dev, sizeof(struct driver_data));
++ master = devm_spi_alloc_master(dev, sizeof(*drv_data));
+ if (!master) {
+ dev_err(&pdev->dev, "cannot alloc spi_master\n");
+ pxa_ssp_free(ssp);
+@@ -1759,7 +1759,6 @@ out_error_dma_irq_alloc:
+ free_irq(ssp->irq, drv_data);
+
+ out_error_master_alloc:
+- spi_controller_put(master);
+ pxa_ssp_free(ssp);
+ return status;
+ }
--- /dev/null
+From foo@baz Fri Jan 15 10:46:02 AM CET 2021
+From: Nick Desaulniers <ndesaulniers@google.com>
+Date: Fri, 21 Aug 2020 12:42:47 -0700
+Subject: vmlinux.lds.h: Add PGO and AutoFDO input sections
+
+From: Nick Desaulniers <ndesaulniers@google.com>
+
+commit eff8728fe69880d3f7983bec3fb6cea4c306261f upstream.
+
+Basically, consider .text.{hot|unlikely|unknown}.* part of .text, too.
+
+When compiling with profiling information (collected via PGO
+instrumentations or AutoFDO sampling), Clang will separate code into
+.text.hot, .text.unlikely, or .text.unknown sections based on profiling
+information. After D79600 (clang-11), these sections will have a
+trailing `.` suffix, ie. .text.hot., .text.unlikely., .text.unknown..
+
+When using -ffunction-sections together with profiling infomation,
+either explicitly (FGKASLR) or implicitly (LTO), code may be placed in
+sections following the convention:
+.text.hot.<foo>, .text.unlikely.<bar>, .text.unknown.<baz>
+where <foo>, <bar>, and <baz> are functions. (This produces one section
+per function; we generally try to merge these all back via linker script
+so that we don't have 50k sections).
+
+For the above cases, we need to teach our linker scripts that such
+sections might exist and that we'd explicitly like them grouped
+together, otherwise we can wind up with code outside of the
+_stext/_etext boundaries that might not be mapped properly for some
+architectures, resulting in boot failures.
+
+If the linker script is not told about possible input sections, then
+where the section is placed as output is a heuristic-laiden mess that's
+non-portable between linkers (ie. BFD and LLD), and has resulted in many
+hard to debug bugs. Kees Cook is working on cleaning this up by adding
+--orphan-handling=warn linker flag used in ARCH=powerpc to additional
+architectures. In the case of linker scripts, borrowing from the Zen of
+Python: explicit is better than implicit.
+
+Also, ld.bfd's internal linker script considers .text.hot AND
+.text.hot.* to be part of .text, as well as .text.unlikely and
+.text.unlikely.*. I didn't see support for .text.unknown.*, and didn't
+see Clang producing such code in our kernel builds, but I see code in
+LLVM that can produce such section names if profiling information is
+missing. That may point to a larger issue with generating or collecting
+profiles, but I would much rather be safe and explicit than have to
+debug yet another issue related to orphan section placement.
+
+Reported-by: Jian Cai <jiancai@google.com>
+Suggested-by: Fāng-ruì Sòng <maskray@google.com>
+Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
+Signed-off-by: Kees Cook <keescook@chromium.org>
+Signed-off-by: Ingo Molnar <mingo@kernel.org>
+Tested-by: Luis Lozano <llozano@google.com>
+Tested-by: Manoj Gupta <manojgupta@google.com>
+Acked-by: Kees Cook <keescook@chromium.org>
+Cc: linux-arch@vger.kernel.org
+Cc: stable@vger.kernel.org
+Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=add44f8d5c5c05e08b11e033127a744d61c26aee
+Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=1de778ed23ce7492c523d5850c6c6dbb34152655
+Link: https://reviews.llvm.org/D79600
+Link: https://bugs.chromium.org/p/chromium/issues/detail?id=1084760
+Link: https://lore.kernel.org/r/20200821194310.3089815-7-keescook@chromium.org
+
+Debugged-by: Luis Lozano <llozano@google.com>
+[nc: Resolve small conflict due to lack of NOINSTR_TEXT]
+Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ include/asm-generic/vmlinux.lds.h | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+--- a/include/asm-generic/vmlinux.lds.h
++++ b/include/asm-generic/vmlinux.lds.h
+@@ -492,7 +492,10 @@
+ */
+ #define TEXT_TEXT \
+ ALIGN_FUNCTION(); \
+- *(.text.hot TEXT_MAIN .text.fixup .text.unlikely) \
++ *(.text.hot .text.hot.*) \
++ *(TEXT_MAIN .text.fixup) \
++ *(.text.unlikely .text.unlikely.*) \
++ *(.text.unknown .text.unknown.*) \
+ *(.text..refcount) \
+ *(.ref.text) \
+ MEM_KEEP(init.text*) \
--- /dev/null
+From foo@baz Fri Jan 15 10:40:16 AM CET 2021
+From: Reinette Chatre <reinette.chatre@intel.com>
+Date: Mon, 11 Jan 2021 15:16:26 -0800
+Subject: x86/resctrl: Don't move a task to the same resource group
+To: stable@vger.kernel.org, gregkh@linuxfoundation.org
+Cc: Fenghua Yu <fenghua.yu@intel.com>, Shakeel Butt <shakeelb@google.com>, Reinette Chatre <reinette.chatre@intel.com>, Borislav Petkov <bp@suse.de>, Tony Luck <tony.luck@intel.com>
+Message-ID: <c25a23cdb5d64bef08c0d8dc60c9bc9a146ad2bd.1610394070.git.reinette.chatre@intel.com>
+
+From: Fenghua Yu <fenghua.yu@intel.com>
+
+commit a0195f314a25582b38993bf30db11c300f4f4611 upstream
+
+Shakeel Butt reported in [1] that a user can request a task to be moved
+to a resource group even if the task is already in the group. It just
+wastes time to do the move operation which could be costly to send IPI
+to a different CPU.
+
+Add a sanity check to ensure that the move operation only happens when
+the task is not already in the resource group.
+
+[1] https://lore.kernel.org/lkml/CALvZod7E9zzHwenzf7objzGKsdBmVwTgEJ0nPgs0LUFU3SN5Pw@mail.gmail.com/
+
+Backporting notes:
+
+Since upstream commit fa7d949337cc ("x86/resctrl: Rename and move rdt
+files to a separate directory"), the file
+arch/x86/kernel/cpu/intel_rdt_rdtgroup.c has been renamed and moved to
+arch/x86/kernel/cpu/resctrl/rdtgroup.c.
+Apply the change against file arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+for older stable trees.
+
+Fixes: e02737d5b826 ("x86/intel_rdt: Add tasks files")
+Reported-by: Shakeel Butt <shakeelb@google.com>
+Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
+Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
+Signed-off-by: Borislav Petkov <bp@suse.de>
+Reviewed-by: Tony Luck <tony.luck@intel.com>
+Cc: stable@vger.kernel.org
+Link: https://lkml.kernel.org/r/962ede65d8e95be793cb61102cca37f7bb018e66.1608243147.git.reinette.chatre@intel.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 7 +++++++
+ 1 file changed, 7 insertions(+)
+
+--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
++++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+@@ -554,6 +554,13 @@ static void update_task_closid_rmid(stru
+ static int __rdtgroup_move_task(struct task_struct *tsk,
+ struct rdtgroup *rdtgrp)
+ {
++ /* If the task is already in rdtgrp, no need to move the task. */
++ if ((rdtgrp->type == RDTCTRL_GROUP && tsk->closid == rdtgrp->closid &&
++ tsk->rmid == rdtgrp->mon.rmid) ||
++ (rdtgrp->type == RDTMON_GROUP && tsk->rmid == rdtgrp->mon.rmid &&
++ tsk->closid == rdtgrp->mon.parent->closid))
++ return 0;
++
+ /*
+ * Set the task's closid/rmid before the PQR_ASSOC MSR can be
+ * updated by them.
--- /dev/null
+From foo@baz Fri Jan 15 10:40:16 AM CET 2021
+From: Reinette Chatre <reinette.chatre@intel.com>
+Date: Mon, 11 Jan 2021 15:15:59 -0800
+Subject: x86/resctrl: Use an IPI instead of task_work_add() to update PQR_ASSOC MSR
+To: stable@vger.kernel.org, gregkh@linuxfoundation.org
+Cc: Fenghua Yu <fenghua.yu@intel.com>, Shakeel Butt <shakeelb@google.com>, Valentin Schneider <valentin.schneider@arm.com>, Reinette Chatre <reinette.chatre@intel.com>, Borislav Petkov <bp@suse.de>, Tony Luck <tony.luck@intel.com>, James Morse <james.morse@arm.com>
+Message-ID: <f69002fadfbfca6e559e779fe55db3cf29b8603a.1610394070.git.reinette.chatre@intel.com>
+
+From: Fenghua Yu <fenghua.yu@intel.com>
+
+commit ae28d1aae48a1258bd09a6f707ebb4231d79a761 upstream
+
+Currently, when moving a task to a resource group the PQR_ASSOC MSR is
+updated with the new closid and rmid in an added task callback. If the
+task is running, the work is run as soon as possible. If the task is not
+running, the work is executed later in the kernel exit path when the
+kernel returns to the task again.
+
+Updating the PQR_ASSOC MSR as soon as possible on the CPU a moved task
+is running is the right thing to do. Queueing work for a task that is
+not running is unnecessary (the PQR_ASSOC MSR is already updated when
+the task is scheduled in) and causing system resource waste with the way
+in which it is implemented: Work to update the PQR_ASSOC register is
+queued every time the user writes a task id to the "tasks" file, even if
+the task already belongs to the resource group.
+
+This could result in multiple pending work items associated with a
+single task even if they are all identical and even though only a single
+update with most recent values is needed. Specifically, even if a task
+is moved between different resource groups while it is sleeping then it
+is only the last move that is relevant but yet a work item is queued
+during each move.
+
+This unnecessary queueing of work items could result in significant
+system resource waste, especially on tasks sleeping for a long time.
+For example, as demonstrated by Shakeel Butt in [1] writing the same
+task id to the "tasks" file can quickly consume significant memory. The
+same problem (wasted system resources) occurs when moving a task between
+different resource groups.
+
+As pointed out by Valentin Schneider in [2] there is an additional issue
+with the way in which the queueing of work is done in that the task_struct
+update is currently done after the work is queued, resulting in a race with
+the register update possibly done before the data needed by the update is
+available.
+
+To solve these issues, update the PQR_ASSOC MSR in a synchronous way
+right after the new closid and rmid are ready during the task movement,
+only if the task is running. If a moved task is not running nothing
+is done since the PQR_ASSOC MSR will be updated next time the task is
+scheduled. This is the same way used to update the register when tasks
+are moved as part of resource group removal.
+
+[1] https://lore.kernel.org/lkml/CALvZod7E9zzHwenzf7objzGKsdBmVwTgEJ0nPgs0LUFU3SN5Pw@mail.gmail.com/
+[2] https://lore.kernel.org/lkml/20201123022433.17905-1-valentin.schneider@arm.com
+
+ [ bp: Massage commit message and drop the two update_task_closid_rmid()
+ variants. ]
+
+Backporting notes:
+
+Since upstream commit fa7d949337cc ("x86/resctrl: Rename and move rdt
+files to a separate directory"), the file
+arch/x86/kernel/cpu/intel_rdt_rdtgroup.c has been renamed and moved to
+arch/x86/kernel/cpu/resctrl/rdtgroup.c.
+Apply the change against file arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+for older stable trees.
+
+Since upstream commit 352940ececaca ("x86/resctrl: Rename the RDT
+functions and definitions"), resctrl functions received more generic
+names. Specifically related to this backport, intel_rdt_sched_in()
+was renamed to rescrl_sched_in().
+
+Fixes: e02737d5b826 ("x86/intel_rdt: Add tasks files")
+Reported-by: Shakeel Butt <shakeelb@google.com>
+Reported-by: Valentin Schneider <valentin.schneider@arm.com>
+Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
+Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
+Signed-off-by: Borislav Petkov <bp@suse.de>
+Reviewed-by: Tony Luck <tony.luck@intel.com>
+Reviewed-by: James Morse <james.morse@arm.com>
+Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
+Cc: stable@vger.kernel.org
+Link: https://lkml.kernel.org/r/17aa2fb38fc12ce7bb710106b3e7c7b45acb9e94.1608243147.git.reinette.chatre@intel.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 108 ++++++++++++-------------------
+ 1 file changed, 43 insertions(+), 65 deletions(-)
+
+--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
++++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+@@ -533,85 +533,63 @@ static void rdtgroup_remove(struct rdtgr
+ kfree(rdtgrp);
+ }
+
+-struct task_move_callback {
+- struct callback_head work;
+- struct rdtgroup *rdtgrp;
+-};
+-
+-static void move_myself(struct callback_head *head)
++static void _update_task_closid_rmid(void *task)
+ {
+- struct task_move_callback *callback;
+- struct rdtgroup *rdtgrp;
+-
+- callback = container_of(head, struct task_move_callback, work);
+- rdtgrp = callback->rdtgrp;
+-
+ /*
+- * If resource group was deleted before this task work callback
+- * was invoked, then assign the task to root group and free the
+- * resource group.
++ * If the task is still current on this CPU, update PQR_ASSOC MSR.
++ * Otherwise, the MSR is updated when the task is scheduled in.
+ */
+- if (atomic_dec_and_test(&rdtgrp->waitcount) &&
+- (rdtgrp->flags & RDT_DELETED)) {
+- current->closid = 0;
+- current->rmid = 0;
+- rdtgroup_remove(rdtgrp);
+- }
+-
+- preempt_disable();
+- /* update PQR_ASSOC MSR to make resource group go into effect */
+- intel_rdt_sched_in();
+- preempt_enable();
++ if (task == current)
++ intel_rdt_sched_in();
++}
+
+- kfree(callback);
++static void update_task_closid_rmid(struct task_struct *t)
++{
++ if (IS_ENABLED(CONFIG_SMP) && task_curr(t))
++ smp_call_function_single(task_cpu(t), _update_task_closid_rmid, t, 1);
++ else
++ _update_task_closid_rmid(t);
+ }
+
+ static int __rdtgroup_move_task(struct task_struct *tsk,
+ struct rdtgroup *rdtgrp)
+ {
+- struct task_move_callback *callback;
+- int ret;
+-
+- callback = kzalloc(sizeof(*callback), GFP_KERNEL);
+- if (!callback)
+- return -ENOMEM;
+- callback->work.func = move_myself;
+- callback->rdtgrp = rdtgrp;
+-
+ /*
+- * Take a refcount, so rdtgrp cannot be freed before the
+- * callback has been invoked.
++ * Set the task's closid/rmid before the PQR_ASSOC MSR can be
++ * updated by them.
++ *
++ * For ctrl_mon groups, move both closid and rmid.
++ * For monitor groups, can move the tasks only from
++ * their parent CTRL group.
+ */
+- atomic_inc(&rdtgrp->waitcount);
+- ret = task_work_add(tsk, &callback->work, true);
+- if (ret) {
+- /*
+- * Task is exiting. Drop the refcount and free the callback.
+- * No need to check the refcount as the group cannot be
+- * deleted before the write function unlocks rdtgroup_mutex.
+- */
+- atomic_dec(&rdtgrp->waitcount);
+- kfree(callback);
+- rdt_last_cmd_puts("task exited\n");
+- } else {
+- /*
+- * For ctrl_mon groups move both closid and rmid.
+- * For monitor groups, can move the tasks only from
+- * their parent CTRL group.
+- */
+- if (rdtgrp->type == RDTCTRL_GROUP) {
+- tsk->closid = rdtgrp->closid;
++
++ if (rdtgrp->type == RDTCTRL_GROUP) {
++ tsk->closid = rdtgrp->closid;
++ tsk->rmid = rdtgrp->mon.rmid;
++ } else if (rdtgrp->type == RDTMON_GROUP) {
++ if (rdtgrp->mon.parent->closid == tsk->closid) {
+ tsk->rmid = rdtgrp->mon.rmid;
+- } else if (rdtgrp->type == RDTMON_GROUP) {
+- if (rdtgrp->mon.parent->closid == tsk->closid) {
+- tsk->rmid = rdtgrp->mon.rmid;
+- } else {
+- rdt_last_cmd_puts("Can't move task to different control group\n");
+- ret = -EINVAL;
+- }
++ } else {
++ rdt_last_cmd_puts("Can't move task to different control group\n");
++ return -EINVAL;
+ }
+ }
+- return ret;
++
++ /*
++ * Ensure the task's closid and rmid are written before determining if
++ * the task is current that will decide if it will be interrupted.
++ */
++ barrier();
++
++ /*
++ * By now, the task's closid and rmid are set. If the task is current
++ * on a CPU, the PQR_ASSOC MSR needs to be updated to make the resource
++ * group go into effect. If the task is not current, the MSR will be
++ * updated when the task is scheduled in.
++ */
++ update_task_closid_rmid(tsk);
++
++ return 0;
+ }
+
+ /**
projects / thirdparty / kernel / stable-queue.git / commitdiff
