Currently, installation of Debian 12.8 for mipsel fails on machines
without an FPU [1]. This is caused by the fact that zstd (which is used
for initramfs compression) executes the prefx instruction, which is not
emulated properly by the kernel.
The prefx (Prefetch Indexed) instruction fetches data from memory into
the cache without any side effects. Though functionally unrelated, it
requires an FPU [2].
Bytecode format of this instruction ends on "001111" binary:
(prefx instruction format) & 0x0000003f = 0x0000000f
The code in fpux_emu() runs like so:
#define MIPSInst(x) x
#define MIPSInst_FMA_FFMT(x) (MIPSInst(x) & 0x00000007)
#define MIPSInst_FUNC(x) (MIPSInst(x) & 0x0000003f)
enum cop1x_func { ..., pfetch_op = 0x0f, ... };
...
switch (MIPSInst_FMA_FFMT(ir)) {
...
case 0x3:
if (MIPSInst_FUNC(ir) != pfetch_op)
return SIGILL;
/* ignore prefx operation */
break;
default:
return SIGILL;
}
That snippet above contains a logic error and the
if (MIPSInst_FUNC(ir) != pfetch_op)
comparison always fires.
When MIPSInst_FUNC(ir) is equal to pfetch_op, ir must end on 001111
binary. In this case, MIPSInst_FMA_FFMT(ir) must be equal to 0x7, which
does not match that case label.
This causes emulation failure for the prefx instruction. Fix it.
This has been broken by
commit 919af8b96c89 ("MIPS: Make definitions of MIPSInst_FMA_{FUNC,FMTM} consistent with MIPS64 manual")
which modified the MIPSInst_FMA_FFMT macro without updating the users.
Signed-off-by: Mateusz Jończyk <mat.jonczyk(a)o2.pl>
Cc: stable(a)vger.kernel.org # after 3 weeks
Cc: Dengcheng Zhu <dzhu(a)wavecomp.com>
Cc: Thomas Bogendoerfer <tsbogend(a)alpha.franken.de>
Cc: Ming Wang <wangming01(a)loongson.cn>
Cc: Tiezhu Yang <yangtiezhu(a)loongson.cn>
Fixes: 919af8b96c89 ("MIPS: Make definitions of MIPSInst_FMA_{FUNC,FMTM} consistent with MIPS64 manual")
[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1091858
[2] MIPS Architecture For Programmers Volume II-A: The MIPS32 Instruction Set
---
Tested in QEMU for mipsel and mips64el.
---
arch/mips/math-emu/cp1emu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index 265bc57819df..c89e70df43d8 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -1660,7 +1660,7 @@ static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
break;
}
- case 0x3:
+ case 0x7:
if (MIPSInst_FUNC(ir) != pfetch_op)
return SIGILL;
--
2.25.1
Once device_register() failed, we should call put_device() to
decrement reference count for cleanup. Or it could cause memory leak.
device_register() includes device_add(). As comment of device_add()
says, 'if device_add() succeeds, you should call device_del() when you
want to get rid of it. If device_add() has not succeeded, use only
put_device() to drop the reference count'.
Found by code review.
Cc: stable(a)vger.kernel.org
Fixes: 37d6a0a6f470 ("PCI: Add pci_register_host_bridge() interface")
Signed-off-by: Ma Ke <make24(a)iscas.ac.cn>
---
drivers/pci/probe.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 2e81ab0f5a25..73464ffbb0fc 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -974,8 +974,10 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
name = dev_name(&bus->dev);
err = device_register(&bus->dev);
- if (err)
+ if (err) {
+ put_device(&bus->dev);
goto unregister;
+ }
pcibios_add_bus(bus);
--
2.25.1
Once device_register() failed, we should call put_device() to
decrement reference count for cleanup. Or it could cause memory leak.
device_register() includes device_add(). As comment of device_add()
says, 'if device_add() succeeds, you should call device_del() when you
want to get rid of it. If device_add() has not succeeded, use only
put_device() to drop the reference count'.
Found by code review.
Cc: stable(a)vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Ma Ke <make24(a)iscas.ac.cn>
---
arch/arm/common/locomo.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm/common/locomo.c b/arch/arm/common/locomo.c
index cb6ef449b987..7274010218ec 100644
--- a/arch/arm/common/locomo.c
+++ b/arch/arm/common/locomo.c
@@ -255,6 +255,7 @@ locomo_init_one_child(struct locomo *lchip, struct locomo_dev_info *info)
ret = device_register(&dev->dev);
if (ret) {
+ put_device(&dev->dev);
out:
kfree(dev);
}
--
2.25.1
This patch series is to fix bugs and improve codes regarding various
driver core device iterating APIs
Signed-off-by: Zijun Hu <quic_zijuhu(a)quicinc.com>
---
Changes in v6:
- Remove dependencies since they have been merged into driver-core tree
- Link to v5: https://lore.kernel.org/r/20241224-class_fix-v5-0-9eaaf7abe843@quicinc.com
Changes in v5:
- Add comments back and correct tile and commit messages for patch 8/8.
- Link to v4: https://lore.kernel.org/r/20241218-class_fix-v4-0-3c40f098356b@quicinc.com
Changes in v4:
- Squich patches 3-5 into one based on Jonathan and Fan comments.
- Add one more patch
- Link to v3: https://lore.kernel.org/r/20241212-class_fix-v3-0-04e20c4f0971@quicinc.com
Changes in v3:
- Correct commit message, add fix tag, and correct pr_crit() message for 1st patch
- Add more patches regarding driver core device iterating APIs.
- Link to v2: https://lore.kernel.org/r/20241112-class_fix-v2-0-73d198d0a0d5@quicinc.com
Changes in v2:
- Remove both fix and stable tag for patch 1/3
- drop patch 3/3
- Link to v1: https://lore.kernel.org/r/20241105-class_fix-v1-0-80866f9994a5@quicinc.com
---
Zijun Hu (8):
driver core: class: Fix wild pointer dereferences in API class_dev_iter_next()
blk-cgroup: Fix class @block_class's subsystem refcount leakage
driver core: Move true expression out of if condition in 3 device finding APIs
driver core: Rename declaration parameter name for API device_find_child() cluster
driver core: Correct parameter check for API device_for_each_child_reverse_from()
driver core: Correct API device_for_each_child_reverse_from() prototype
driver core: Introduce device_iter_t for device iterating APIs
driver core: Move two simple APIs for finding child device to header
block/blk-cgroup.c | 1 +
drivers/base/bus.c | 9 +++++---
drivers/base/class.c | 11 ++++++++--
drivers/base/core.c | 49 +++++++++----------------------------------
drivers/base/driver.c | 9 +++++---
drivers/cxl/core/hdm.c | 2 +-
drivers/cxl/core/region.c | 2 +-
include/linux/device.h | 46 +++++++++++++++++++++++++++++++---------
include/linux/device/bus.h | 7 +++++--
include/linux/device/class.h | 4 ++--
include/linux/device/driver.h | 2 +-
11 files changed, 78 insertions(+), 64 deletions(-)
---
base-commit: 7687c66c18c66d4ccd9949c6f641c0e7b5773483
change-id: 20241104-class_fix-f176bd9eba22
Best regards,
--
Zijun Hu <quic_zijuhu(a)quicinc.com>
From: Chen-Yu Tsai <wenst(a)chromium.org>
[ Upstream commit 32c9c06adb5b157ef259233775a063a43746d699 ]
On Chromebooks based on Mediatek MT8195 or MT8188, the audio frontend
(AFE) is limited to accessing a very small window (1 MiB) of memory,
which is described as a reserved memory region in the device tree.
On these two platforms, the maximum buffer size is given as 512 KiB.
The MediaTek common code uses the same value for preallocations. This
means that only the first two PCM substreams get preallocations, and
then the whole space is exhausted, barring any other substreams from
working. Since the substreams used are not always the first two, this
means audio won't work correctly.
This is observed on the MT8188 Geralt Chromebooks, on which the
"mediatek,dai-link" property was dropped when it was upstreamed. That
property causes the driver to only register the PCM substreams listed
in the property, and in the order given.
Instead of trying to compute an optimal value and figuring out which
streams are used, simply disable preallocation. The PCM buffers are
managed by the core and are allocated and released on the fly. There
should be no impact to any of the other MediaTek platforms.
Signed-off-by: Chen-Yu Tsai <wenst(a)chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno(a)collabora.com>
Link: https://patch.msgid.link/20241219105303.548437-1-wenst@chromium.org
Signed-off-by: Mark Brown <broonie(a)kernel.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
sound/soc/mediatek/common/mtk-afe-platform-driver.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/sound/soc/mediatek/common/mtk-afe-platform-driver.c b/sound/soc/mediatek/common/mtk-afe-platform-driver.c
index 01501d5747a7..52495c930ca3 100644
--- a/sound/soc/mediatek/common/mtk-afe-platform-driver.c
+++ b/sound/soc/mediatek/common/mtk-afe-platform-driver.c
@@ -120,8 +120,8 @@ int mtk_afe_pcm_new(struct snd_soc_component *component,
struct mtk_base_afe *afe = snd_soc_component_get_drvdata(component);
size = afe->mtk_afe_hardware->buffer_bytes_max;
- snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
- afe->dev, size, size);
+ snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV, afe->dev, 0, size);
+
return 0;
}
EXPORT_SYMBOL_GPL(mtk_afe_pcm_new);
--
2.39.5
From: Chen-Yu Tsai <wenst(a)chromium.org>
[ Upstream commit 32c9c06adb5b157ef259233775a063a43746d699 ]
On Chromebooks based on Mediatek MT8195 or MT8188, the audio frontend
(AFE) is limited to accessing a very small window (1 MiB) of memory,
which is described as a reserved memory region in the device tree.
On these two platforms, the maximum buffer size is given as 512 KiB.
The MediaTek common code uses the same value for preallocations. This
means that only the first two PCM substreams get preallocations, and
then the whole space is exhausted, barring any other substreams from
working. Since the substreams used are not always the first two, this
means audio won't work correctly.
This is observed on the MT8188 Geralt Chromebooks, on which the
"mediatek,dai-link" property was dropped when it was upstreamed. That
property causes the driver to only register the PCM substreams listed
in the property, and in the order given.
Instead of trying to compute an optimal value and figuring out which
streams are used, simply disable preallocation. The PCM buffers are
managed by the core and are allocated and released on the fly. There
should be no impact to any of the other MediaTek platforms.
Signed-off-by: Chen-Yu Tsai <wenst(a)chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno(a)collabora.com>
Link: https://patch.msgid.link/20241219105303.548437-1-wenst@chromium.org
Signed-off-by: Mark Brown <broonie(a)kernel.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
sound/soc/mediatek/common/mtk-afe-platform-driver.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/sound/soc/mediatek/common/mtk-afe-platform-driver.c b/sound/soc/mediatek/common/mtk-afe-platform-driver.c
index 01501d5747a7..52495c930ca3 100644
--- a/sound/soc/mediatek/common/mtk-afe-platform-driver.c
+++ b/sound/soc/mediatek/common/mtk-afe-platform-driver.c
@@ -120,8 +120,8 @@ int mtk_afe_pcm_new(struct snd_soc_component *component,
struct mtk_base_afe *afe = snd_soc_component_get_drvdata(component);
size = afe->mtk_afe_hardware->buffer_bytes_max;
- snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
- afe->dev, size, size);
+ snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV, afe->dev, 0, size);
+
return 0;
}
EXPORT_SYMBOL_GPL(mtk_afe_pcm_new);
--
2.39.5
From: Chen-Yu Tsai <wenst(a)chromium.org>
[ Upstream commit 32c9c06adb5b157ef259233775a063a43746d699 ]
On Chromebooks based on Mediatek MT8195 or MT8188, the audio frontend
(AFE) is limited to accessing a very small window (1 MiB) of memory,
which is described as a reserved memory region in the device tree.
On these two platforms, the maximum buffer size is given as 512 KiB.
The MediaTek common code uses the same value for preallocations. This
means that only the first two PCM substreams get preallocations, and
then the whole space is exhausted, barring any other substreams from
working. Since the substreams used are not always the first two, this
means audio won't work correctly.
This is observed on the MT8188 Geralt Chromebooks, on which the
"mediatek,dai-link" property was dropped when it was upstreamed. That
property causes the driver to only register the PCM substreams listed
in the property, and in the order given.
Instead of trying to compute an optimal value and figuring out which
streams are used, simply disable preallocation. The PCM buffers are
managed by the core and are allocated and released on the fly. There
should be no impact to any of the other MediaTek platforms.
Signed-off-by: Chen-Yu Tsai <wenst(a)chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno(a)collabora.com>
Link: https://patch.msgid.link/20241219105303.548437-1-wenst@chromium.org
Signed-off-by: Mark Brown <broonie(a)kernel.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
sound/soc/mediatek/common/mtk-afe-platform-driver.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/sound/soc/mediatek/common/mtk-afe-platform-driver.c b/sound/soc/mediatek/common/mtk-afe-platform-driver.c
index 01501d5747a7..52495c930ca3 100644
--- a/sound/soc/mediatek/common/mtk-afe-platform-driver.c
+++ b/sound/soc/mediatek/common/mtk-afe-platform-driver.c
@@ -120,8 +120,8 @@ int mtk_afe_pcm_new(struct snd_soc_component *component,
struct mtk_base_afe *afe = snd_soc_component_get_drvdata(component);
size = afe->mtk_afe_hardware->buffer_bytes_max;
- snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
- afe->dev, size, size);
+ snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV, afe->dev, 0, size);
+
return 0;
}
EXPORT_SYMBOL_GPL(mtk_afe_pcm_new);
--
2.39.5