From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lowell Gilbert Subject: crash on accessing =?iso-8859-1?Q?=2Fproc=2Fxenomai=2Fsched=2F=C2?= Date: Tue, 29 Jan 2019 16:06:47 -0500 Message-ID: <44k1infa1k.fsf@be-well.ilk.org> MIME-Version: 1.0 Content-Type: text/plain List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: xenomai@xenomai.org I was trying to update to 3.0.8, and looking at stat or acct in the sched branch of the proc tree gives me an instant kernel crash, usually with a null pointer access from a bogus code address, although the locations aren't always the same. This is without even having my kernel module or application loaded. The system is a dual-core Cortex-A9. Any idea what might be going on? Details follow. [ 121.205418] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 121.213493] pgd = ee7e0000 [ 121.216198] [00000000] *pgd=3f8ff831 [ 121.219787] Internal error: Oops: 80000007 [#1] SMP ARM [ 121.225000] Modules linked in: [ 121.228066] CPU: 0 PID: 1113 Comm: cat Not tainted 4.14.73-ltsi-09035-gb67570c09362-dirty #2 [ 121.236474] Hardware name: Altera SOCFPGA [ 121.240475] I-pipe domain: Linux [ 121.243699] task: ef302e00 task.stack: ee656000 [ 121.248221] PC is at 0x0 [ 121.250776] LR is at __ipipe_ack_hrtimer_irq+0x48/0x80 [ 121.255901] pc : [<00000000>] lr : [] psr: a0060193 [ 121.262149] sp : ee657c60 ip : ee657c60 fp : ee657c74 [ 121.267360] r10: 00000001 r9 : 00000012 r8 : ee657ce8 [ 121.272571] r7 : 00000011 r6 : 00000000 r5 : ef004900 r4 : ef7c01b0 [ 121.279077] r3 : 00000000 r2 : c0c919c0 r1 : 00000001 r0 : ef004900 [ 121.285587] Flags: NzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment none [ 121.292786] Control: 10c5387d Table: 2e7e004a DAC: 00000051 [ 121.298517] Process cat (pid: 1113, stack limit = 0xee656220) and [ 121.727414] Unable to handle kernel NULL pointer dereference at virtual address 00000024 [ 121.735477] pgd = c0004000 [ 121.738183] [00000024] *pgd=00000000 [ 121.741763] Internal error: Oops: 17 [#2] SMP ARM [ 121.746455] Modules linked in: [ 121.749517] CPU: 0 PID: 1113 Comm: cat Tainted: G D 4.14.73-ltsi-09035-gb67570c09362-dirty #2 [ 121.759134] Hardware name: Altera SOCFPGA [ 121.763133] I-pipe domain: Linux [ 121.766356] task: ef302e00 task.stack: ee656000 [ 121.770880] PC is at unmap_page_range+0x6c/0x624 [ 121.775488] LR is at unmap_single_vma+0x8c/0x94 [ 121.780008] pc : [] lr : [] psr: 20060113 [ 121.786255] sp : ee657920 ip : c026a624 fp : ee6579a4 [ 121.791464] r10: ee657a08 r9 : c0939688 r8 : 00010000 [ 121.796675] r7 : ee657a08 r6 : 00010000 r5 : eea41f00 r4 : 00000001 [ 121.803181] r3 : 00000000 r2 : 00000000 r1 : 00018000 r0 : c0ccb3c0 [ 121.809689] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none [ 121.816800] Control: 10c5387d Table: 2e7e004a DAC: 00000051 [ 121.822530] Process cat (pid: 1113, stack limit = 0xee656220) [ 121.828259] Stack: (0xee657920 to 0xee658000)