On 10/30/2017 1:46 PM, Linus Torvalds wrote:
On Mon, Oct 30, 2017 at 10:20 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
I will add a "might_sleep()" to ioremap_page_range() itself, so that
we get this warning more reliably and much eailer. Right now it has
been hidden by the fact that most of the time the time the page tables
may be already allocated, but even then it's broken.
Done. It doesn't report anything for me, so _hopefully_ the GHES
driver is the only one that does games like this. See commit
b39ab98e2f47 ("Mark 'ioremap_page_range()' as possibly sleeping").
So now it should hopefully warn about this bad usage of page remapping
reliably, at least if you have CONFIG_DEBUG_ATOMIC_SLEEP enabled.
Can somebody who has a working GHES setup (although Borislav seems to
think no such thing exists) verify?
Hello Linus,
I have verified that this flags the error for me every time ghes_proc() is used.
But I also see it flagged in ARM PMU code:
[ 7.381153] BUG: sleeping function called from invalid context at mm/slab.h:420
[ 7.387625] in_atomic(): 0, irqs_disabled(): 128, pid: 11, name: cpuhp/0
[ 7.394310] CPU: 0 PID: 11 Comm: cpuhp/0 Not tainted 4.14.0-rc7 #46
[ 7.400559] Hardware name: Qualcomm Qualcomm Centriq(TM) 2400 Development
Platform
[ 7.414361] Call trace:
[ 7.416797] [<ffff000008088b28>] dump_backtrace+0x0/0x270
[ 7.422175] [<ffff000008088dbc>] show_stack+0x24/0x30
[ 7.427211] [<ffff0000090d01f0>] dump_stack+0x98/0xb8
[ 7.432246] [<ffff00000810118c>] ___might_sleep+0x104/0x128
[ 7.437799] [<ffff000008101208>] __might_sleep+0x58/0x90
[ 7.443097] [<ffff000008254a7c>] kmem_cache_alloc_trace+0x224/0x280
[ 7.449347] [<ffff000008e9c938>] armpmu_alloc+0x30/0x168
[ 7.454639] [<ffff000008e9d15c>] arm_pmu_acpi_cpu_starting+0x114/0x148
[ 7.461151] [<ffff0000080d0f30>] cpuhp_invoke_callback+0xb8/0x760
[ 7.467226] [<ffff0000080d1ec4>] cpuhp_thread_fun+0xa4/0x1b8
[ 7.472872] [<ffff0000080f661c>] smpboot_thread_fn+0x174/0x250
[ 7.478684] [<ffff0000080f18ec>] kthread+0x114/0x140
[ 7.483632] [<ffff000008084774>] ret_from_fork+0x10/0x1c
For a GHES polling source:
[ 47.944596] BUG: sleeping function called from invalid context at
lib/ioremap.c:164
[ 47.951290] in_atomic(): 1, irqs_disabled(): 128, pid: 0, name: swapper/19
[ 47.958150] CPU: 19 PID: 0 Comm: swapper/19 Tainted: G W 4.14.0-rc7 #46
[ 47.958152] Hardware name: Qualcomm Qualcomm Centriq(TM) 2400 Development
Platform
[ 47.958154] Call trace:
[ 47.958161] [<ffff000008088b28>] dump_backtrace+0x0/0x270
[ 47.958165] [<ffff000008088dbc>] show_stack+0x24/0x30
[ 47.958169] [<ffff0000090d01f0>] dump_stack+0x98/0xb8
[ 47.958174] [<ffff00000810118c>] ___might_sleep+0x104/0x128
[ 47.958177] [<ffff000008101208>] __might_sleep+0x58/0x90
[ 47.958180] [<ffff0000090d3d20>] ioremap_page_range+0x40/0x310
[ 47.958185] [<ffff0000086c5a98>] ghes_copy_tofrom_phys+0x1f8/0x240
[ 47.958188] [<ffff0000086c5da8>] ghes_proc+0xb0/0x8f0
[ 47.958190] [<ffff0000086c6ae8>] ghes_poll_func+0x20/0x40
[ 47.958196] [<ffff00000814b3dc>] call_timer_fn+0x3c/0x1b0
[ 47.958198] [<ffff00000814b638>] expire_timers+0xe8/0x170
[ 47.958201] [<ffff00000814b7fc>] run_timer_softirq+0x13c/0x188
[ 47.958203] [<ffff000008081964>] __do_softirq+0x144/0x33c
[ 47.958206] [<ffff0000080d6e78>] irq_exit+0xd0/0x108
[ 47.958210] [<ffff00000812dc44>] __handle_domain_irq+0x6c/0xc0
[ 47.958212] [<ffff000008081764>] gic_handle_irq+0xcc/0x188
For a GHES interrupt source:
[ 265.502603] BUG: sleeping function called from invalid context at
lib/ioremap.c:164
[ 265.509296] in_atomic(): 1, irqs_disabled(): 128, pid: 3, name: kworker/0:0
[ 265.516242] CPU: 0 PID: 3 Comm: kworker/0:0 Tainted: G W 4.14.0-rc7 #46
[ 265.516244] Hardware name: Qualcomm Qualcomm Centriq(TM) 2400 Development
Platform
[ 265.516251] Workqueue: kacpi_notify acpi_os_execute_deferred
[ 265.516254] Call trace:
[ 265.516258] [<ffff000008088b28>] dump_backtrace+0x0/0x270
[ 265.516261] [<ffff000008088dbc>] show_stack+0x24/0x30
[ 265.516264] [<ffff0000090d01f0>] dump_stack+0x98/0xb8
[ 265.516268] [<ffff00000810118c>] ___might_sleep+0x104/0x128
[ 265.516270] [<ffff000008101208>] __might_sleep+0x58/0x90
[ 265.516273] [<ffff0000090d3d20>] ioremap_page_range+0x40/0x310
[ 265.516277] [<ffff0000086c5a98>] ghes_copy_tofrom_phys+0x1f8/0x240
[ 265.516279] [<ffff0000086c5da8>] ghes_proc+0xb0/0x8f0
[ 265.516282] [<ffff0000086c6670>] ghes_notify_hed+0x50/0x90
[ 265.516286] [<ffff0000080f36a4>] notifier_call_chain+0x5c/0xa0
[ 265.516289] [<ffff0000080f3b80>] __blocking_notifier_call_chain+0x58/0xa0
[ 265.516291] [<ffff0000080f3c04>] blocking_notifier_call_chain+0x3c/0x50
[ 265.516293] [<ffff0000086c1140>] acpi_hed_notify+0x28/0x30
[ 265.516296] [<ffff000008678100>] acpi_device_notify+0x30/0x40
[ 265.516301] [<ffff000008691fb8>] acpi_ev_notify_dispatch+0x64/0x74
[ 265.516304] [<ffff00000867296c>] acpi_os_execute_deferred+0x24/0x38
[ 265.516308] [<ffff0000080ea748>] process_one_work+0x1f8/0x488
[ 265.516310] [<ffff0000080eaa30>] worker_thread+0x58/0x4a0
[ 265.516312] [<ffff0000080f18ec>] kthread+0x114/0x140
[ 265.516315] [<ffff000008084774>] ret_from_fork+0x10/0x1c
Thanks,
Tyler
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