From: Barry Song <v-songbaohua(a)oppo.com>
Commit 13ddaf26be32 ("mm/swap: fix race when skipping swapcache")
introduced an unconditional one-tick sleep when `swapcache_prepare()`
fails, which has led to reports of UI stuttering on latency-sensitive
Android devices. To address this, we can use a waitqueue to wake up
tasks that fail `swapcache_prepare()` sooner, instead of always
sleeping for a full tick. While tasks may occasionally be woken by an
unrelated `do_swap_page()`, this method is preferable to two scenarios:
rapid re-entry into page faults, which can cause livelocks, and
multiple millisecond sleeps, which visibly degrade user experience.
Oven's testing shows that a single waitqueue resolves the UI
stuttering issue. If a 'thundering herd' problem becomes apparent
later, a waitqueue hash similar to `folio_wait_table[PAGE_WAIT_TABLE_SIZE]`
for page bit locks can be introduced.
Fixes: 13ddaf26be32 ("mm/swap: fix race when skipping swapcache")
Cc: Kairui Song <kasong(a)tencent.com>
Cc: "Huang, Ying" <ying.huang(a)intel.com>
Cc: Yu Zhao <yuzhao(a)google.com>
Cc: David Hildenbrand <david(a)redhat.com>
Cc: Chris Li <chrisl(a)kernel.org>
Cc: Hugh Dickins <hughd(a)google.com>
Cc: Johannes Weiner <hannes(a)cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org>
Cc: Michal Hocko <mhocko(a)suse.com>
Cc: Minchan Kim <minchan(a)kernel.org>
Cc: Yosry Ahmed <yosryahmed(a)google.com>
Cc: SeongJae Park <sj(a)kernel.org>
Cc: Kalesh Singh <kaleshsingh(a)google.com>
Cc: Suren Baghdasaryan <surenb(a)google.com>
Cc: <stable(a)vger.kernel.org>
Reported-by: Oven Liyang <liyangouwen1(a)oppo.com>
Tested-by: Oven Liyang <liyangouwen1(a)oppo.com>
Signed-off-by: Barry Song <v-songbaohua(a)oppo.com>
---
mm/memory.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index 2366578015ad..6913174f7f41 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4192,6 +4192,8 @@ static struct folio *alloc_swap_folio(struct vm_fault *vmf)
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+static DECLARE_WAIT_QUEUE_HEAD(swapcache_wq);
+
/*
* We enter with non-exclusive mmap_lock (to exclude vma changes,
* but allow concurrent faults), and pte mapped but not yet locked.
@@ -4204,6 +4206,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct folio *swapcache, *folio = NULL;
+ DECLARE_WAITQUEUE(wait, current);
struct page *page;
struct swap_info_struct *si = NULL;
rmap_t rmap_flags = RMAP_NONE;
@@ -4302,7 +4305,9 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
* Relax a bit to prevent rapid
* repeated page faults.
*/
+ add_wait_queue(&swapcache_wq, &wait);
schedule_timeout_uninterruptible(1);
+ remove_wait_queue(&swapcache_wq, &wait);
goto out_page;
}
need_clear_cache = true;
@@ -4609,8 +4614,10 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
pte_unmap_unlock(vmf->pte, vmf->ptl);
out:
/* Clear the swap cache pin for direct swapin after PTL unlock */
- if (need_clear_cache)
+ if (need_clear_cache) {
swapcache_clear(si, entry, nr_pages);
+ wake_up(&swapcache_wq);
+ }
if (si)
put_swap_device(si);
return ret;
@@ -4625,8 +4632,10 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
folio_unlock(swapcache);
folio_put(swapcache);
}
- if (need_clear_cache)
+ if (need_clear_cache) {
swapcache_clear(si, entry, nr_pages);
+ wake_up(&swapcache_wq);
+ }
if (si)
put_swap_device(si);
return ret;
--
2.34.1
Stuart Hayhurst has found that both at bootup and fullscreen VA-API video
is leading to black screens for around 1 second and kernel WARNING [1] traces
when calling dmub_psr_enable() with Parade 08-01 TCON.
These symptoms all go away with PSR-SU disabled for this TCON, so disable
it for now while DMUB traces [2] from the failure can be analyzed and the failure
state properly root caused.
Cc: stable(a)vger.kernel.org
Cc: Marc Rossi <Marc.Rossi(a)amd.com>
Cc: Hamza Mahfooz <Hamza.Mahfooz(a)amd.com>
Link: https://gitlab.freedesktop.org/drm/amd/uploads/a832dd515b571ee171b3e3b566e9… [1]
Link: https://gitlab.freedesktop.org/drm/amd/uploads/8f13ff3b00963c833e23e68aa811… [2]
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/2645
Signed-off-by: Mario Limonciello <mario.limonciello(a)amd.com>
---
---
drivers/gpu/drm/amd/display/modules/power/power_helpers.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/modules/power/power_helpers.c b/drivers/gpu/drm/amd/display/modules/power/power_helpers.c
index e304e8435fb8..477289846a0a 100644
--- a/drivers/gpu/drm/amd/display/modules/power/power_helpers.c
+++ b/drivers/gpu/drm/amd/display/modules/power/power_helpers.c
@@ -841,6 +841,8 @@ bool is_psr_su_specific_panel(struct dc_link *link)
isPSRSUSupported = false;
else if (dpcd_caps->sink_dev_id_str[1] == 0x08 && dpcd_caps->sink_dev_id_str[0] == 0x03)
isPSRSUSupported = false;
+ else if (dpcd_caps->sink_dev_id_str[1] == 0x08 && dpcd_caps->sink_dev_id_str[0] == 0x01)
+ isPSRSUSupported = false;
else if (dpcd_caps->psr_info.force_psrsu_cap == 0x1)
isPSRSUSupported = true;
}
--
2.34.1
The IMAGE_DLLCHARACTERISTICS_NX_COMPAT informs the firmware that the
EFI binary does not rely on pages that are both executable and
writable.
The flag is used by some distro versions of GRUB to decide if the EFI
binary may be executed.
As the Linux kernel neither has RWX sections nor needs RWX pages for
relocation we should set the flag.
Cc: Ard Biesheuvel <ardb(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt(a)canonical.com>
---
arch/riscv/kernel/efi-header.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/riscv/kernel/efi-header.S b/arch/riscv/kernel/efi-header.S
index 515b2dfbca75..c5f17c2710b5 100644
--- a/arch/riscv/kernel/efi-header.S
+++ b/arch/riscv/kernel/efi-header.S
@@ -64,7 +64,7 @@ extra_header_fields:
.long efi_header_end - _start // SizeOfHeaders
.long 0 // CheckSum
.short IMAGE_SUBSYSTEM_EFI_APPLICATION // Subsystem
- .short 0 // DllCharacteristics
+ .short IMAGE_DLL_CHARACTERISTICS_NX_COMPAT // DllCharacteristics
.quad 0 // SizeOfStackReserve
.quad 0 // SizeOfStackCommit
.quad 0 // SizeOfHeapReserve
--
2.45.2
iowarrior_read() uses the iowarrior dev structure, but does not use any
lock on the structure. This can cause various bugs including data-races,
so it is more appropriate to use a mutex lock to safely protect the
iowarrior dev structure. When using a mutex lock, you should split the
branch to prevent blocking when the O_NONBLOCK flag is set.
In addition, it is unnecessary to check for NULL on the iowarrior dev
structure obtained by reading file->private_data. Therefore, it is
better to remove the check.
Cc: stable(a)vger.kernel.org
Fixes: 946b960d13c1 ("USB: add driver for iowarrior devices.")
Signed-off-by: Jeongjun Park <aha310510(a)gmail.com>
---
v1 -> v2: Added cc tag and change log
drivers/usb/misc/iowarrior.c | 46 ++++++++++++++++++++++++++++--------
1 file changed, 36 insertions(+), 10 deletions(-)
diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c
index 6d28467ce352..a513766b4985 100644
--- a/drivers/usb/misc/iowarrior.c
+++ b/drivers/usb/misc/iowarrior.c
@@ -277,28 +277,45 @@ static ssize_t iowarrior_read(struct file *file, char __user *buffer,
struct iowarrior *dev;
int read_idx;
int offset;
+ int retval;
dev = file->private_data;
+ if (file->f_flags & O_NONBLOCK) {
+ retval = mutex_trylock(&dev->mutex);
+ if (!retval)
+ return -EAGAIN;
+ } else {
+ retval = mutex_lock_interruptible(&dev->mutex);
+ if (retval)
+ return -ERESTARTSYS;
+ }
+
/* verify that the device wasn't unplugged */
- if (!dev || !dev->present)
- return -ENODEV;
+ if (!dev->present) {
+ retval = -ENODEV;
+ goto exit;
+ }
dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
dev->minor, count);
/* read count must be packet size (+ time stamp) */
if ((count != dev->report_size)
- && (count != (dev->report_size + 1)))
- return -EINVAL;
+ && (count != (dev->report_size + 1))) {
+ retval = -EINVAL;
+ goto exit;
+ }
/* repeat until no buffer overrun in callback handler occur */
do {
atomic_set(&dev->overflow_flag, 0);
if ((read_idx = read_index(dev)) == -1) {
/* queue empty */
- if (file->f_flags & O_NONBLOCK)
- return -EAGAIN;
+ if (file->f_flags & O_NONBLOCK) {
+ retval = -EAGAIN;
+ goto exit;
+ }
else {
//next line will return when there is either new data, or the device is unplugged
int r = wait_event_interruptible(dev->read_wait,
@@ -309,28 +326,37 @@ static ssize_t iowarrior_read(struct file *file, char __user *buffer,
-1));
if (r) {
//we were interrupted by a signal
- return -ERESTART;
+ retval = -ERESTART;
+ goto exit;
}
if (!dev->present) {
//The device was unplugged
- return -ENODEV;
+ retval = -ENODEV;
+ goto exit;
}
if (read_idx == -1) {
// Can this happen ???
- return 0;
+ retval = 0;
+ goto exit;
}
}
}
offset = read_idx * (dev->report_size + 1);
if (copy_to_user(buffer, dev->read_queue + offset, count)) {
- return -EFAULT;
+ retval = -EFAULT;
+ goto exit;
}
} while (atomic_read(&dev->overflow_flag));
read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
atomic_set(&dev->read_idx, read_idx);
+ mutex_unlock(&dev->mutex);
return count;
+
+exit:
+ mutex_unlock(&dev->mutex);
+ return retval;
}
/*
--
The new test case which checks non unique symbol kprobe_non_uniq_symbol.tc
failed because of missing kernel functionality support from commit
b022f0c7e404 ("tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols").
Backport it and its fix commit to 5.4.y together. Resolved minor context change conflicts.
Andrii Nakryiko (1):
tracing/kprobes: Fix symbol counting logic by looking at modules as
well
Francis Laniel (1):
tracing/kprobes: Return EADDRNOTAVAIL when func matches several
symbols
kernel/trace/trace_kprobe.c | 76 +++++++++++++++++++++++++++++++++++++
kernel/trace/trace_probe.h | 1 +
2 files changed, 77 insertions(+)
--
2.46.0
A problem was introduced with commit f69759be251d ("x86/CPU/AMD: Move
Zenbleed check to the Zen2 init function") where a bit in the DE_CFG MSR
is getting set after a microcode late load.
The problem seems to be that the microcode late load path calls into
amd_check_microcode() and subsequently zen2_zenbleed_check(). Since the
patch removes the cpu_has_amd_erratum() check from zen2_zenbleed_check(),
this will cause all non-Zen2 CPUs to go through the function and set
the bit in the DE_CFG MSR.
Call into the zenbleed fix path on Zen2 CPUs only.
Fixes: f69759be251d ("x86/CPU/AMD: Move Zenbleed check to the Zen2 init function")
Cc: <stable(a)vger.kernel.org>
Acked-by: Borislav Petkov (AMD) <bp(a)alien8.de>
Signed-off-by: John Allen <john.allen(a)amd.com>
---
v2:
- Clean up commit description
---
arch/x86/kernel/cpu/amd.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 015971adadfc..368344e1394b 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -1202,5 +1202,6 @@ void amd_check_microcode(void)
if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
return;
- on_each_cpu(zenbleed_check_cpu, NULL, 1);
+ if (boot_cpu_has(X86_FEATURE_ZEN2))
+ on_each_cpu(zenbleed_check_cpu, NULL, 1);
}
--
2.34.1