Function show_regs() is usually called in interrupt handler or exception
handler, it prints the registers specified by the parameter 'regs', then
dump the stack traces. Although not explicitly documented, dump the stack
traces based on'regs' seems to make the most sense. Although dump_stack()
can finally dump the desired content, because 'regs' are saved by the
entry of current interrupt or exception. In the following example we can
see: 1) The backtrace of interrupt or exception handler is not expected,
it causes confusion. 2) Something is printed repeatedly. The line with
the kernel version "CPU: 0 PID: 70 Comm: test0 Not tainted 5.19.0+ #8",
the registers saved in "Exception stack" which 'regs' actually point to.
For example:
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 0-....: (499 ticks this GP) idle=379/1/0x40000002 softirq=91/91 fqs=249
(t=500 jiffies g=-911 q=13 ncpus=4)
CPU: 0 PID: 70 Comm: test0 Not tainted 5.19.0+ #8
Hardware name: ARM-Versatile Express
PC is at ktime_get+0x4c/0xe8
LR is at ktime_get+0x4c/0xe8
pc : 8019a474 lr : 8019a474 psr: 60000013
sp : cabd1f28 ip : 00000001 fp : 00000005
r10: 527bf1b8 r9 : 431bde82 r8 : d7b634db
r7 : 0000156e r6 : 61f234f8 r5 : 00000001 r4 : 80ca86c0
r3 : ffffffff r2 : fe5bce0b r1 : 00000000 r0 : 01a431f4
Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
Control: 10c5387d Table: 6121406a DAC: 00000051
CPU: 0 PID: 70 Comm: test0 Not tainted 5.19.0+ #8 <-----------start----------
Hardware name: ARM-Versatile Express |
unwind_backtrace from show_stack+0x10/0x14 |
show_stack from dump_stack_lvl+0x40/0x4c |
dump_stack_lvl from rcu_dump_cpu_stacks+0x10c/0x134 |
rcu_dump_cpu_stacks from rcu_sched_clock_irq+0x780/0xaf4 |
rcu_sched_clock_irq from update_process_times+0x54/0x74 |
update_process_times from tick_periodic+0x3c/0xd4 |
tick_periodic from tick_handle_periodic+0x20/0x80 worthless
tick_handle_periodic from twd_handler+0x30/0x40 or
twd_handler from handle_percpu_devid_irq+0x8c/0x1c8 duplicated
handle_percpu_devid_irq from generic_handle_domain_irq+0x24/0x34 |
generic_handle_domain_irq from gic_handle_irq+0x74/0x88 |
gic_handle_irq from generic_handle_arch_irq+0x34/0x44 |
generic_handle_arch_irq from call_with_stack+0x18/0x20 |
call_with_stack from __irq_svc+0x98/0xb0 |
Exception stack(0xcabd1ed8 to 0xcabd1f20) |
1ec0: 01a431f4 00000000 |
1ee0: fe5bce0b ffffffff 80ca86c0 00000001 61f234f8 0000156e d7b634db 431bde82 |
1f00: 527bf1b8 00000005 00000001 cabd1f28 8019a474 8019a474 60000013 ffffffff |
__irq_svc from ktime_get+0x4c/0xe8 <---------end--------------
ktime_get from test_task+0x44/0x110
test_task from kthread+0xd8/0xf4
kthread from ret_from_fork+0x14/0x2c
Exception stack(0xcabd1fb0 to 0xcabd1ff8)
1fa0: 00000000 00000000 00000000 00000000
1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
1fe0: 00000000 00000000 00000000 00000000 00000013 00000000
After replacing dump_stack() with dump_backtrace():
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 0-....: (500 ticks this GP) idle=8f7/1/0x40000002 softirq=129/129 fqs=241
(t=500 jiffies g=-915 q=13 ncpus=4)
CPU: 0 PID: 69 Comm: test0 Not tainted 5.19.0+ #9
Hardware name: ARM-Versatile Express
PC is at ktime_get+0x4c/0xe8
LR is at ktime_get+0x4c/0xe8
pc : 8019a494 lr : 8019a494 psr: 60000013
sp : cabddf28 ip : 00000001 fp : 00000002
r10: 0779cb48 r9 : 431bde82 r8 : d7b634db
r7 : 00000a66 r6 : e835ab70 r5 : 00000001 r4 : 80ca86c0
r3 : ffffffff r2 : ff337d39 r1 : 00000000 r0 : 00cc82c6
Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
Control: 10c5387d Table: 611d006a DAC: 00000051
ktime_get from test_task+0x44/0x110
test_task from kthread+0xd8/0xf4
kthread from ret_from_fork+0x14/0x2c
Exception stack(0xcabddfb0 to 0xcabddff8)
dfa0: 00000000 00000000 00000000 00000000
dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
dfe0: 00000000 00000000 00000000 00000000 00000013 00000000
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Russell King (Oracle) <[email protected]>
The error message is not printed immediately because it does not end with
a newline character.
Before:
root@localhost:~# insmod vmlinux.ko
insmod: ERROR: could not insert module vmlinux.ko: Invalid parameters
After:
root@localhost:~# insmod vmlinux.ko
[ 43.982558] livepatch: vmlinux.ko: invalid module name
insmod: ERROR: could not insert module vmlinux.ko: Invalid parameters
Fixes: dcf550e52f ("livepatch: Disallow vmlinux.ko")
Signed-off-by: Zhen Lei <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Signed-off-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
The hardware automatically disable the IRQ interrupt before jumping to the
interrupt or exception vector. Therefore, the preempt_disable() operation
in this_cpu_read() after macro expansion is unnecessary. In fact, function
this_cpu_read() may trigger scheduling, see pseudocode below.
Pseudocode of this_cpu_read(xx):
preempt_disable_notrace();
raw_cpu_read(xx);
if (unlikely(__preempt_count_dec_and_test()))
__preempt_schedule_notrace();
Therefore, use raw_cpu_* instead of this_cpu_* to eliminate potential
hazards. At the very least, it reduces a few lines of assembly code.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Russell King (Oracle) <[email protected]>
The dump_cpu_task() function does not print registers on architectures
that do not support NMIs. However, registers can be useful for
debugging. Fortunately, in the case where dump_cpu_task() is invoked
from an interrupt handler and is dumping the current CPU's stack, the
get_irq_regs() function can be used to get the registers.
Therefore, this commit makes dump_cpu_task() check to see if it is being
asked to dump the current CPU's stack from within an interrupt handler,
and, if so, it uses the get_irq_regs() function to obtain the registers.
On systems that do support NMIs, this commit has the further advantage
of avoiding a self-NMI in this case.
This is an example of rcu self-detected stall on arm64, which does not
support NMIs:
[ 27.501721] rcu: INFO: rcu_preempt self-detected stall on CPU
[ 27.502238] rcu: 0-....: (1250 ticks this GP) idle=4f7/1/0x4000000000000000 softirq=2594/2594 fqs=619
[ 27.502632] (t=1251 jiffies g=2989 q=29 ncpus=4)
[ 27.503845] CPU: 0 PID: 306 Comm: test0 Not tainted 5.19.0-rc7-00009-g1c1a6c29ff99-dirty #46
[ 27.504732] Hardware name: linux,dummy-virt (DT)
[ 27.504947] pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 27.504998] pc : arch_counter_read+0x18/0x24
[ 27.505301] lr : arch_counter_read+0x18/0x24
[ 27.505328] sp : ffff80000b29bdf0
[ 27.505345] x29: ffff80000b29bdf0 x28: 0000000000000000 x27: 0000000000000000
[ 27.505475] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
[ 27.505553] x23: 0000000000001f40 x22: ffff800009849c48 x21: 000000065f871ae0
[ 27.505627] x20: 00000000000025ec x19: ffff80000a6eb300 x18: ffffffffffffffff
[ 27.505654] x17: 0000000000000001 x16: 0000000000000000 x15: ffff80000a6d0296
[ 27.505681] x14: ffffffffffffffff x13: ffff80000a29bc18 x12: 0000000000000426
[ 27.505709] x11: 0000000000000162 x10: ffff80000a2f3c18 x9 : ffff80000a29bc18
[ 27.505736] x8 : 00000000ffffefff x7 : ffff80000a2f3c18 x6 : 00000000759bd013
[ 27.505761] x5 : 01ffffffffffffff x4 : 0002dc6c00000000 x3 : 0000000000000017
[ 27.505787] x2 : 00000000000025ec x1 : ffff80000b29bdf0 x0 : 0000000075a30653
[ 27.505937] Call trace:
[ 27.506002] arch_counter_read+0x18/0x24
[ 27.506171] ktime_get+0x48/0xa0
[ 27.506207] test_task+0x70/0xf0
[ 27.506227] kthread+0x10c/0x110
[ 27.506243] ret_from_fork+0x10/0x20
This is a marked improvement over the old output:
[ 27.944550] rcu: INFO: rcu_preempt self-detected stall on CPU
[ 27.944980] rcu: 0-....: (1249 ticks this GP) idle=cbb/1/0x4000000000000000 softirq=2610/2610 fqs=614
[ 27.945407] (t=1251 jiffies g=2681 q=28 ncpus=4)
[ 27.945731] Task dump for CPU 0:
[ 27.945844] task:test0 state:R running task stack: 0 pid: 306 ppid: 2 flags:0x0000000a
[ 27.946073] Call trace:
[ 27.946151] dump_backtrace.part.0+0xc8/0xd4
[ 27.946378] show_stack+0x18/0x70
[ 27.946405] sched_show_task+0x150/0x180
[ 27.946427] dump_cpu_task+0x44/0x54
[ 27.947193] rcu_dump_cpu_stacks+0xec/0x130
[ 27.947212] rcu_sched_clock_irq+0xb18/0xef0
[ 27.947231] update_process_times+0x68/0xac
[ 27.947248] tick_sched_handle+0x34/0x60
[ 27.947266] tick_sched_timer+0x4c/0xa4
[ 27.947281] __hrtimer_run_queues+0x178/0x360
[ 27.947295] hrtimer_interrupt+0xe8/0x244
[ 27.947309] arch_timer_handler_virt+0x38/0x4c
[ 27.947326] handle_percpu_devid_irq+0x88/0x230
[ 27.947342] generic_handle_domain_irq+0x2c/0x44
[ 27.947357] gic_handle_irq+0x44/0xc4
[ 27.947376] call_on_irq_stack+0x2c/0x54
[ 27.947415] do_interrupt_handler+0x80/0x94
[ 27.947431] el1_interrupt+0x34/0x70
[ 27.947447] el1h_64_irq_handler+0x18/0x24
[ 27.947462] el1h_64_irq+0x64/0x68 <--- the above backtrace is worthless
[ 27.947474] arch_counter_read+0x18/0x24
[ 27.947487] ktime_get+0x48/0xa0
[ 27.947501] test_task+0x70/0xf0
[ 27.947520] kthread+0x10c/0x110
[ 27.947538] ret_from_fork+0x10/0x20
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Vincent Guittot <[email protected]>
Cc: Dietmar Eggemann <[email protected]>
Cc: Ben Segall <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Daniel Bristot de Oliveira <[email protected]>
Cc: Valentin Schneider <[email protected]>
The trigger_all_cpu_backtrace() function attempts to send an NMI to the
target CPU, which usually provides much better stack traces than the
dump_cpu_task() function's approach of dumping that stack from some other
CPU. So much so that most calls to dump_cpu_task() only happen after
a call to trigger_all_cpu_backtrace() has failed. And the exception to
this rule really should attempt to use trigger_all_cpu_backtrace() first.
Therefore, move the trigger_all_cpu_backtrace() invocation into
dump_cpu_task().
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Vincent Guittot <[email protected]>
Cc: Dietmar Eggemann <[email protected]>
Cc: Ben Segall <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Daniel Bristot de Oliveira <[email protected]>
Cc: Valentin Schneider <[email protected]>
Currently, the values of some fields are printed right-aligned, causing
the field value to be next to the next field name rather than next to its
own field name. So print each field value left-aligned, to make it more
readable.
Before:
stack: 0 pid: 307 ppid: 2 flags:0x00000008
After:
stack:0 pid:308 ppid:2 flags:0x0000000a
This also makes them print in the same style as the other two fields:
task:demo0 state:R running task
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Reviewed-by: Valentin Schneider <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
commit 7a1be318f5 ("ARM: 9012/1: move device tree mapping out of linear
region") use FDT_FIXED_BASE to map the whole FDT_FIXED_SIZE memory area
which contains fdt. But it only reserves the exact physical memory that
fdt occupied. Unfortunately, this mapping is non-shareable. An illegal or
speculative read access can bring the RAM content from non-fdt zone into
cache, PIPT makes it to be hit by subsequently read access through
shareable mapping(such as linear mapping), and the cache consistency
between cores is lost due to non-shareable property.
|<---------FDT_FIXED_SIZE------>|
| |
-------------------------------
| <non-fdt> | <fdt> | <non-fdt> |
-------------------------------
1. CoreA read <non-fdt> through MT_ROM mapping, the old data is loaded
into the cache.
2. CoreB write <non-fdt> to update data through linear mapping. CoreA
received the notification to invalid the corresponding cachelines, but
the property non-shareable makes it to be ignored.
3. CoreA read <non-fdt> through linear mapping, cache hit, the old data
is read.
To eliminate this risk, add a new memory type MT_MEMORY_RO. Compared to
MT_ROM, it is shareable and non-executable.
Here's an example:
list_del corruption. prev->next should be c0ecbf74, but was c08410dc
kernel BUG at lib/list_debug.c:53!
... ...
PC is at __list_del_entry_valid+0x58/0x98
LR is at __list_del_entry_valid+0x58/0x98
psr: 60000093
sp : c0ecbf30 ip : 00000000 fp : 00000001
r10: c08410d0 r9 : 00000001 r8 : c0825e0c
r7 : 20000013 r6 : c08410d0 r5 : c0ecbf74 r4 : c0ecbf74
r3 : c0825d08 r2 : 00000000 r1 : df7ce6f4 r0 : 00000044
... ...
Stack: (0xc0ecbf30 to 0xc0ecc000)
bf20: c0ecbf74 c0164fd0 c0ecbf70 c0165170
bf40: c0eca000 c0840c00 c0840c00 c0824500 c0825e0c c0189bbc c088f404 60000013
bf60: 60000013 c0e85100 000004ec 00000000 c0ebcdc0 c0ecbf74 c0ecbf74 c0825d08
... ... < next prev >
(__list_del_entry_valid) from (__list_del_entry+0xc/0x20)
(__list_del_entry) from (finish_swait+0x60/0x7c)
(finish_swait) from (rcu_gp_kthread+0x560/0xa20)
(rcu_gp_kthread) from (kthread+0x14c/0x15c)
(kthread) from (ret_from_fork+0x14/0x24)
The faulty list node to be deleted is a local variable, its address is
c0ecbf74. The dumped stack shows that 'prev' = c0ecbf74, but its value
before lib/list_debug.c:53 is c08410dc. A large amount of printing results
in swapping out the cacheline containing the old data(MT_ROM mapping is
read only, so the cacheline cannot be dirty), and the subsequent dump
operation obtains new data from the DDR.
Fixes: 7a1be318f5 ("ARM: 9012/1: move device tree mapping out of linear region")
Suggested-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Reviewed-by: Ard Biesheuvel <[email protected]>
Reviewed-by: Kefeng Wang <[email protected]>
Signed-off-by: Russell King (Oracle) <[email protected]>
When "crashkernel=X,high" is specified, the specified "crashkernel=Y,low"
memory is not required in the following corner cases:
1. If both CONFIG_ZONE_DMA and CONFIG_ZONE_DMA32 are disabled, it means
that the devices can access any memory.
2. If the system memory is small, the crash high memory may be allocated
from the DMA zones. If that happens, there's no need to allocate
another crash low memory because there's already one.
Add condition '(crash_base >= CRASH_ADDR_LOW_MAX)' to determine whether
the 'high' memory is allocated above DMA zones. Note: when both
CONFIG_ZONE_DMA and CONFIG_ZONE_DMA32 are disabled, the entire physical
memory is DMA accessible, CRASH_ADDR_LOW_MAX equals 'PHYS_MASK + 1'.
Signed-off-by: Zhen Lei <[email protected]>
Acked-by: Baoquan He <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>
When "crashkernel=X,high" is used, there may be two crash regions:
high=crashk_res and low=crashk_low_res. But now the syscall
kexec_file_load() only add crashk_res into "linux,usable-memory-range",
this may cause the second kernel to have no available dma memory.
Fix it like kexec-tools does for option -c, add both 'high' and 'low'
regions into the dtb.
Signed-off-by: Zhen Lei <[email protected]>
Acked-by: Rob Herring <[email protected]>
Acked-by: Baoquan He <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>
insert_resource() traverses the subtree layer by layer from the root node
until a proper location is found. Compared with request_resource(), the
parent node does not need to be determined in advance.
In addition, move the insertion of node 'crashk_res' into function
reserve_crashkernel() to make the associated code close together.
Signed-off-by: Zhen Lei <[email protected]>
Acked-by: John Donnelly <[email protected]>
Acked-by: Baoquan He <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>
According to the current crashkernel=Y,low support in other ARCHes, it's
an optional command-line option. When it doesn't exist, kernel will try
to allocate minimum required memory below 4G automatically.
However, __parse_crashkernel() returns '-EINVAL' for all error cases. It
can't distinguish the nonexistent option from invalid option.
Change __parse_crashkernel() to return '-ENOENT' for the nonexistent option
case. With this change, crashkernel,low memory will take the default
value if crashkernel=,low is not specified; while crashkernel reservation
will fail and bail out if an invalid option is specified.
Signed-off-by: Zhen Lei <[email protected]>
Acked-by: Baoquan He <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>
Currently, the entry->prev and entry->next are considered to be valid as
long as they are not LIST_POISON{1|2}. However, the memory may be
corrupted. The prev->next is invalid probably because 'prev' is
invalid, not because prev->next's content is illegal.
Unfortunately, the printk and its subfunctions will modify the registers
that hold the 'prev' and 'next', and we don't see this valuable
information in the BUG context.
So print the contents of 'entry->prev' and 'entry->next'.
Here's an example:
list_del corruption. prev->next should be c0ecbf74, but was c08410dc
kernel BUG at lib/list_debug.c:53!
... ...
PC is at __list_del_entry_valid+0x58/0x98
LR is at __list_del_entry_valid+0x58/0x98
psr: 60000093
sp : c0ecbf30 ip : 00000000 fp : 00000001
r10: c08410d0 r9 : 00000001 r8 : c0825e0c
r7 : 20000013 r6 : c08410d0 r5 : c0ecbf74 r4 : c0ecbf74
r3 : c0825d08 r2 : 00000000 r1 : df7ce6f4 r0 : 00000044
... ...
Stack: (0xc0ecbf30 to 0xc0ecc000)
bf20: c0ecbf74 c0164fd0 c0ecbf70 c0165170
bf40: c0eca000 c0840c00 c0840c00 c0824500 c0825e0c c0189bbc c088f404 60000013
bf60: 60000013 c0e85100 000004ec 00000000 c0ebcdc0 c0ecbf74 c0ecbf74 c0825d08
bf80: c0e807c0 c018965c 00000000 c013f2a0 c0e807c0 c013f154 00000000 00000000
bfa0: 00000000 00000000 00000000 c01001b0 00000000 00000000 00000000 00000000
bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
(__list_del_entry_valid) from (__list_del_entry+0xc/0x20)
(__list_del_entry) from (finish_swait+0x60/0x7c)
(finish_swait) from (rcu_gp_kthread+0x560/0xa20)
(rcu_gp_kthread) from (kthread+0x14c/0x15c)
(kthread) from (ret_from_fork+0x14/0x24)
At first, I thought prev->next was overwritten. Later, I carefully
analyzed the RCU code and the disassembly code. The error occurred when
deleting a node from the list rcu_state.gp_wq. The System.map shows
that the address of rcu_state is c0840c00. Then I use gdb to obtain the
offset of rcu_state.gp_wq.task_list.
(gdb) p &((struct rcu_state *)0)->gp_wq.task_list
$1 = (struct list_head *) 0x4dc
Again:
list_del corruption. prev->next should be c0ecbf74, but was c08410dc
c08410dc = c0840c00 + 0x4dc = &rcu_state.gp_wq.task_list
Because rcu_state.gp_wq has at most one node, so I can guess that "prev
= &rcu_state.gp_wq.task_list". But for other scenes, maybe I wasn't so
lucky, I cannot figure out the value of 'prev'.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Zhen Lei <[email protected]>
Cc: "Paul E . McKenney" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Currently, we parse the "linux,usable-memory-range" property in
early_init_dt_scan_chosen(), to obtain the specified memory range of the
crash kernel. We then reserve the required memory after
early_init_dt_scan_memory() has identified all available physical memory.
Because the two pieces of code are separated far, the readability and
maintainability are reduced. So bring them together.
Suggested-by: Rob Herring <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
(change the prototype of early_init_dt_check_for_usable_mem_range(), in
order to use it outside)
Signed-off-by: Pingfan Liu <[email protected]>
Tested-by: Dave Kleikamp <[email protected]>
Acked-by: John Donnelly <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
To: [email protected]
To: [email protected]
Signed-off-by: Rob Herring <[email protected]>
Use DEVICE_ATTR_RO() helper macro instead of DEVICE_ATTR(), which is
simpler and more readable.
Due to the name of the read function of the sysfs attribute is normalized,
there is a natural association.
Link: https://lore.kernel.org/linux-media/[email protected]
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
1. Build command CMD_SYNC cannot fail. So the return value can be ignored.
2. The arm_smmu_cmdq_build_cmd() almost never fails, the addition of
"unlikely()" can optimize the instruction pipeline.
3. Check the return value in arm_smmu_cmdq_batch_add().
Signed-off-by: Zhen Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>
Pre-zeroing the batched commands structure is inefficient, as individual
commands are zeroed later in arm_smmu_cmdq_build_cmd(). Therefore, only
the member 'num' needs to be initialized to 0.
Signed-off-by: Zhen Lei <[email protected]>
Reviewed-by: John Garry <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>
When the refcount is decreased to 0, the resource reclamation branch is
entered. Before CPU0 reaches the race point (1), CPU1 may obtain the
spinlock and traverse the rbtree to find 'root', see
nilfs_lookup_root().
Although CPU1 will call refcount_inc() to increase the refcount, it is
obviously too late. CPU0 will release 'root' directly, CPU1 then
accesses 'root' and triggers UAF.
Use refcount_dec_and_lock() to ensure that both the operations of
decrease refcount to 0 and link deletion are lock protected eliminates
this risk.
CPU0 CPU1
nilfs_put_root():
<-------- (1)
spin_lock(&nilfs->ns_cptree_lock);
rb_erase(&root->rb_node, &nilfs->ns_cptree);
spin_unlock(&nilfs->ns_cptree_lock);
kfree(root);
<-------- use-after-free
refcount_t: underflow; use-after-free.
WARNING: CPU: 2 PID: 9476 at lib/refcount.c:28 \
refcount_warn_saturate+0x1cf/0x210 lib/refcount.c:28
Modules linked in:
CPU: 2 PID: 9476 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ...
RIP: 0010:refcount_warn_saturate+0x1cf/0x210 lib/refcount.c:28
... ...
Call Trace:
__refcount_sub_and_test include/linux/refcount.h:283 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
nilfs_put_root+0xc1/0xd0 fs/nilfs2/the_nilfs.c:795
nilfs_segctor_destroy fs/nilfs2/segment.c:2749 [inline]
nilfs_detach_log_writer+0x3fa/0x570 fs/nilfs2/segment.c:2812
nilfs_put_super+0x2f/0xf0 fs/nilfs2/super.c:467
generic_shutdown_super+0xcd/0x1f0 fs/super.c:464
kill_block_super+0x4a/0x90 fs/super.c:1446
deactivate_locked_super+0x6a/0xb0 fs/super.c:335
deactivate_super+0x85/0x90 fs/super.c:366
cleanup_mnt+0x277/0x2e0 fs/namespace.c:1118
__cleanup_mnt+0x15/0x20 fs/namespace.c:1125
task_work_run+0x8e/0x110 kernel/task_work.c:151
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop kernel/entry/common.c:164 [inline]
exit_to_user_mode_prepare+0x13c/0x170 kernel/entry/common.c:191
syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
entry_SYSCALL_64_after_hwframe+0x44/0xa9
There is no reproduction program, and the above is only theoretical
analysis.
Link: https://lkml.kernel.org/r/[email protected]
Fixes: ba65ae4729 ("nilfs2: add checkpoint tree to nilfs object")
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Ryusuke Konishi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
pci_resource_end() can be 0 only when pci_resource_start() is 0.
Otherwise, it is definitely an error. In this case, pci_resource_len()
should be regarded as 0. Therefore, determining whether
pci_resource_start() and pci_resource_end() are both 0 can be reduced to
determining only whether pci_resource_end() is 0.
Although only one condition judgment is reduced, the macro function
pci_resource_len() is widely referenced in the kernel. I used defconfig to
compile the latest kernel on X86, and its binary code size was reduced by
about 3KB.
Before:
[ 2] .rela.text RELA 0000000000000000 093bfcb0
0000000001a67168 0000000000000018 I 68 1 8
After:
[ 2] .rela.text RELA 0000000000000000 093bfcb0
0000000001a66598 0000000000000018 I 68 1 8
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
When SMMU_GERROR.CMDQP_ERR is different to SMMU_GERRORN.CMDQP_ERR, it
indicates that one or more errors have been encountered on a command queue
control page interface. We need to traverse all ECMDQs in that control
page to find all errors. For each ECMDQ error handling, it is much the
same as the CMDQ error handling. This common processing part is extracted
as a new function __arm_smmu_cmdq_skip_err().
Signed-off-by: Zhen Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>
One SMMU has only one normal CMDQ. Therefore, this CMDQ is used regardless
of the core on which the command is inserted. It can be referenced
directly through "smmu->cmdq". However, one SMMU has multiple ECMDQs, and
the ECMDQ used by the core on which the command insertion is executed may
be different. So the helper function arm_smmu_get_cmdq() is added, which
returns the CMDQ/ECMDQ that the current core should use. Currently, the
code that supports ECMDQ is not added. just simply returns "&smmu->cmdq".
Many subfunctions of arm_smmu_cmdq_issue_cmdlist() use "&smmu->cmdq" or
"&smmu->cmdq.q" directly. To support ECMDQ, they need to call the newly
added function arm_smmu_get_cmdq() instead.
Note that normal CMDQ is still required until ECMDQ is available.
Signed-off-by: Zhen Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>
The obvious key to the performance optimization of commit 587e6c10a7
("iommu/arm-smmu-v3: Reduce contention during command-queue insertion") is
to allow multiple cores to insert commands in parallel after a brief mutex
contention.
Obviously, inserting as many commands at a time as possible can reduce the
number of times the mutex contention participates, thereby improving the
overall performance. At least it reduces the number of calls to function
arm_smmu_cmdq_issue_cmdlist().
Therefore, function arm_smmu_cmdq_issue_cmd_with_sync() is added to insert
the 'cmd+sync' commands at a time.
Signed-off-by: Zhen Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>
The obvious key to the performance optimization of commit 587e6c10a7
("iommu/arm-smmu-v3: Reduce contention during command-queue insertion") is
to allow multiple cores to insert commands in parallel after a brief mutex
contention.
Obviously, inserting as many commands at a time as possible can reduce the
number of times the mutex contention participates, thereby improving the
overall performance. At least it reduces the number of calls to function
arm_smmu_cmdq_issue_cmdlist().
Therefore, use command queue batching helpers to insert multiple commands
at a time.
Signed-off-by: Zhen Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>
The value of pcs->flags is not overwritten in function
pcs_parse_bits_in_pinctrl_entry() and its subfunctions, so moving this
check to the beginning of the function eliminates unnecessary rollback
operations.
Signed-off-by: Zhen Lei <[email protected]>
Reviewed-by: Tony Lindgren <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Linus Walleij <[email protected]>
Replace ida_simple_get() with ida_alloc() and ida_simple_remove() with
ida_free(), the latter is more concise and intuitive.
In addition, if ida_alloc() fails, NULL is returned directly. This
eliminates unnecessary initialization of two local variables and an 'if'
judgment.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
In case of error, the function qcom_smem_get() returns ERR_PTR()
and never returns NULL. The NULL test in the return value check
should be replaced with IS_ERR().
Fixes: d566e78dd6 ("media: venus : hfi: add venus image info into smem")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Stanimir Varbanov <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Use DEVICE_ATTR_RW() helper macro instead of DEVICE_ATTR(), which is
simpler and more readable.
Due to the names of the read and write functions of the sysfs attribute is
normalized, there is a natural association.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Sakari Ailus <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Use DEVICE_ATTR_RO() helper macro instead of DEVICE_ATTR(), which is
simpler and more readable.
Due to the name of the read function of the sysfs attribute is normalized,
there is a natural association.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Sakari Ailus <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Use DEVICE_ATTR_RO() helper macro instead of DEVICE_ATTR(), which is
simpler and more readable.
Due to the name of the read function of the sysfs attribute is normalized,
there is a natural association.
Signed-off-by: Zhen Lei <[email protected]>
Acked-by: Pavel Machek <[email protected]>
Signed-off-by: Sakari Ailus <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Use DEVICE_ATTR_RO() helper macro instead of DEVICE_ATTR(), which is
simpler and more readable.
Due to the name of the read function of the sysfs attribute is normalized,
there is a natural association.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Sakari Ailus <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
In error handling branch "if (WARN_ON(node == NUMA_NO_NODE))", the
previously allocated memories are not released. Doing this before
allocating memory eliminates memory leaks.
tj: Note that the condition only occurs when the arch code is pretty broken
and the WARN_ON might as well be BUG_ON().
Signed-off-by: Zhen Lei <[email protected]>
Reviewed-by: Lai Jiangshan <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
Make IOMMU_DEFAULT_LAZY default for when AMD_IOMMU config is set, which
matches current behaviour.
For "fullflush" param, just call iommu_set_dma_strict(true) directly.
Since we get a strict vs lazy mode print already in iommu_subsys_init(),
and maintain a deprecation print when "fullflush" param is passed, drop the
prints in amd_iommu_init_dma_ops().
Finally drop global flag amd_iommu_unmap_flush, as it has no longer has any
purpose.
[jpg: Rebase for relocated file and drop amd_iommu_unmap_flush]
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: John Garry <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>
Make IOMMU_DEFAULT_LAZY default for when INTEL_IOMMU config is set,
as is current behaviour.
Also delete global flag intel_iommu_strict:
- In intel_iommu_setup(), call iommu_set_dma_strict(true) directly. Also
remove the print, as iommu_subsys_init() prints the mode and we have
already marked this param as deprecated.
- For cap_caching_mode() check in intel_iommu_setup(), call
iommu_set_dma_strict(true) directly; also reword the accompanying print
with a level downgrade and also add the missing '\n'.
- For Ironlake GPU, again call iommu_set_dma_strict(true) directly and
keep the accompanying print.
[jpg: Remove intel_iommu_strict]
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: John Garry <[email protected]>
Reviewed-by: Lu Baolu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>
First, add build options IOMMU_DEFAULT_{LAZY|STRICT}, so that we have the
opportunity to set {lazy|strict} mode as default at build time. Then put
the two config options in an choice, as they are mutually exclusive.
[jpg: Make choice between strict and lazy only (and not passthrough)]
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: John Garry <[email protected]>
Reviewed-by: Robin Murphy <[email protected]>
Reviewed-by: Lu Baolu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>
In the case of error handling, the error code returned by the subfunction
should be propagated instead of 0.
Fixes: 1901fb2604 ("Driver core: fix "driver" symlink timing")
Fixes: 23b6904442 ("driver core: add dev_groups to all drivers")
Fixes: 8fd456ec0c ("driver core: Add state_synced sysfs file for devices that support it")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
This race was discovered when I carefully analyzed the code to locate
another firmware-related UAF issue. It can be triggered only when the
firmware load operation is executed during suspend. This possibility is
almost impossible because there are few firmware load and suspend actions
in the actual environment.
CPU0 CPU1
__device_uncache_fw_images(): assign_fw():
fw_cache_piggyback_on_request()
<----- P0
spin_lock(&fwc->name_lock);
...
list_del(&fce->list);
spin_unlock(&fwc->name_lock);
uncache_firmware(fce->name);
<----- P1
kref_get(&fw_priv->ref);
If CPU1 is interrupted at position P0, the new 'fce' has been added to the
list fwc->fw_names by the fw_cache_piggyback_on_request(). In this case,
CPU0 executes __device_uncache_fw_images() and will be able to see it when
it traverses list fwc->fw_names. Before CPU1 executes kref_get() at P1, if
CPU0 further executes uncache_firmware(), the count of fw_priv->ref may
decrease to 0, causing fw_priv to be released in advance.
Move kref_get() to the lock protection range of fwc->name_lock to fix it.
Fixes: ac39b3ea73 ("firmware loader: let caching firmware piggyback on loading firmware")
Acked-by: Luis Chamberlain <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Fix some spelling mistakes in comments found by "codespell":
Hoever ==> However
poiter ==> pointer
representaion ==> representation
uppon ==> upon
independend ==> independent
aquired ==> acquired
mis-match ==> mismatch
scrach ==> scratch
struture ==> structure
Analagous ==> Analogous
interation ==> iteration
And some were discovered manually by Joe Perches and Christoph Lameter:
stroed ==> stored
arch independent ==> an architecture independent
A example structure for ==> Example structure for
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Zhen Lei <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Joe Perches <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
When 'SB_HW_16' check fails, the error code -ENODEV instead of 0 should be
returned, which is the same as that returned when 'WSS_HW_CMI8330' check
fails.
Fixes: 43bcd973d6 ("[ALSA] Add snd_card_set_generic_dev() call to ISA drivers")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Takashi Iwai <[email protected]>
When devm_ioremap_resource() fails, a clear enough error message will be
printed by its subfunction __devm_ioremap_resource(). The error
information contains the device name, failure cause, and possibly resource
information.
Therefore, remove the error printing here to simplify code and reduce the
binary size.
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Jassi Brar <[email protected]>
When devm_ioremap_resource() fails, a clear enough error message will be
printed by its subfunction __devm_ioremap_resource(). The error
information contains the device name, failure cause, and possibly resource
information.
Therefore, remove the error printing here to simplify code and reduce the
binary size.
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Jassi Brar <[email protected]>
When devm_ioremap_resource() fails, a clear enough error message will be
printed by its subfunction __devm_ioremap_resource(). The error
information contains the device name, failure cause, and possibly resource
information.
Therefore, remove the error printing here to simplify code and reduce the
binary size.
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Jassi Brar <[email protected]>
Use DEFINE_RES_MEM() to save a couple of lines of code, which makes the
code a bit shorter and easier to read. The start address does not need to
appear twice.
By the way, the value of '.end' should be "start + size - 1". So the
previous writing should have omitted subtracted 1.
Fixes: acf5e051ac ("MCB: add support for SC31 to mcb-lpc")
Fixes: 73edc8f7cc ("mcb: Added support for LPC or non PCI based MCB carrier")
Signed-off-by: Zhen Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Return error code -ENODEV rather than '0' when the indicator node can not
be found.
Fixes: a56ba8fbcb ("media: leds: as3645a: Add LED flash class driver")
Reported-by: Hulk Robot <[email protected]>
Acked-by: Sakari Ailus <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Pavel Machek <[email protected]>
Fixes the following W=1 kernel build warning:
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c: In function ‘dpu_encoder_phys_cmd_wait_for_commit_done’:
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c:688:31: warning: variable ‘cmd_enc’ set but not used [-Wunused-but-set-variable]
Fixes: fe286893ed ("drm/msm/dpu: Remove unused call in wait_for_commit_done")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Abhinav Kumar <[email protected]>
Signed-off-by: Dmitry Baryshkov <[email protected]>
Signed-off-by: Rob Clark <[email protected]>
The error code returned by platform_get_irq() is stored in 'irq', it's
forgotten to be copied to 'ret' before being returned. As a result, the
value 0 of 'ret' is returned incorrectly.
After the above fix is completed, initializing the local variable 'ret'
to 0 is no longer needed, remove it.
In addition, when dpu_mdss_init() is successfully returned, the value of
'ret' is always 0. Therefore, replace "return ret" with "return 0" to make
the code clearer.
Fixes: 070e64dc1b ("drm/msm/dpu: Convert to a chained irq chip")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Stephen Boyd <[email protected]>
Reviewed-by: Dmitry Baryshkov <[email protected]>
Signed-off-by: Dmitry Baryshkov <[email protected]>
Signed-off-by: Rob Clark <[email protected]>
Fixes scripts/checkpatch.pl warning:
WARNING: Possible unnecessary 'out of memory' message
Remove it can help us save a bit of memory.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Dave Kleikamp <[email protected]>
Use DEFINE_RES_MEM() to save a couple of lines of code, which is simpler
and more readable. The start address does not need to appear twice.
Signed-off-by: Zhen Lei <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
When the call to platform_get_irq() to obtain the IRQ of the lcd fails, the
returned error code should be propagated. However, we currently do not
explicitly assign this error code to 'ret'. As a result, 0 was incorrectly
returned.
Fixes: 7f7b96a8a0 ("drm/kmb: Add support for KeemBay Display")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Anitha Chrisanthus <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Fixes scripts/checkpatch.pl warning:
WARNING: Possible unnecessary 'out of memory' message
Remove it can help us save a bit of memory. After that, the static
function getdqbuf() becomes unnecessary, get rid of it and instead call
kmalloc() directly.
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Jan Kara <[email protected]>
When an expander does not contain any 'phys', an appropriate error code -1
should be returned, as done elsewhere in this function. However, we
currently do not explicitly assign this error code to 'rc'. As a result, 0
was incorrectly returned.
Link: https://lore.kernel.org/r/[email protected]
Fixes: f92363d123 ("[SCSI] mpt3sas: add new driver supporting 12GB SAS")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
Fix to return a negative error code from the error handling case instead
of 0, as done elsewhere in this function.
Fixes: 9ca2d73264 ("ubifs: Limit number of xattrs per inode")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>
Fix to return a negative error code from the error handling case instead
of 0, as done elsewhere in this function.
Fixes: 89df6bfc04 ("uml: DEBUG_SHIRQ fixes")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Acked-By: [email protected]
Signed-off-by: Richard Weinberger <[email protected]>
Fix to return a negative error code from the error handling case instead
of 0, as done elsewhere in this function.
Fixes: a3c77c67a4 ("[PATCH] uml: slirp and slip driver cleanups and fixes")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Acked-By: [email protected]
Signed-off-by: Richard Weinberger <[email protected]>
When devm_ioremap_resource() fails, a clear enough error message will be
printed by its subfunction __devm_ioremap_resource(). The error
information contains the device name, failure cause, and possibly resource
information.
Therefore, remove the error printing here to simplify code and reduce the
binary size.
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Guenter Roeck <[email protected]>
Fixes scripts/checkpatch.pl warning:
WARNING: Possible unnecessary 'out of memory' message
Remove it can help us save a bit of memory.
Also change the return error code from "-1" to "-ENOMEM".
Link: https://lore.kernel.org/r/[email protected]
Acked-by: Jack Wang <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
Use DEVICE_ATTR_RO/RW macro helper instead of plain DEVICE_ATTR, which
makes the code a bit shorter and easier to read.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Use DEVICE_ATTR_ADMIN_RW macro helper instead of plain DEVICE_ATTR, which
makes the code a bit shorter and easier to read.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Use DEVICE_ATTR_RO macro helper instead of plain DEVICE_ATTR, which makes
the code a bit shorter and easier to read.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Use DEVICE_ATTR_RO macro helper instead of plain DEVICE_ATTR, which makes
the code a bit shorter and easier to read.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Use DEVICE_ATTR_ADMIN_RO macro helper instead of plain DEVICE_ATTR, which
makes the code a bit shorter and easier to read.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Use DEVICE_ATTR_RO macro helper instead of plain DEVICE_ATTR, which makes
the code a bit shorter and easier to read.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Use DEVICE_ATTR_RO macro helper instead of plain DEVICE_ATTR, which makes
the code a bit shorter and easier to read.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Use DEVICE_ATTR_RO macro helper instead of plain DEVICE_ATTR, which makes
the code a bit shorter and easier to read.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Use DEVICE_ATTR_RO macro helper instead of plain DEVICE_ATTR, which makes
the code a bit shorter and easier to read.
Signed-off-by: Zhen Lei <[email protected]>
Acked-by: Charles Keepax <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Use DEVICE_ATTR_ADMIN_RW() helper macro instead of DEVICE_ATTR(), making
it simpler and easier to read.
Because the read and write function names of the sysfs attribute have been
normalized, there is a natural association.
Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
When devm_ioremap_resource() fails, a clear enough error message will be
printed by its subfunction __devm_ioremap_resource(). The error
information contains the device name, failure cause, and possibly resource
information.
Therefore, remove the error printing here to simplify code and reduce the
binary size.
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Zhen Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ulf Hansson <[email protected]>
Zhen Lei