Hi Pantelis, In case you do not know the process of ARM core patches. You need to put the patch into Russell's patch system [1] after review gets done. Then the patch will show up on Russell's git tree.
Regards, Shawn [1] http://www.arm.linux.org.uk/developer/patches/ On Fri, May 25, 2012 at 07:58:36PM +0000, Pantelis Antoniou wrote: > omap2plus_defconfig builds with SMP & SMP_ON_UP set. > On beagle (which is UP) is_smp() returns false and we don't call > smp_init_cpus which in turn does not initialize smp_cross_call which > remains NULL. > > When issuing a reboot we OOPS with a NULL dereference on stop smp_call. > > Fixed by a check with if (!cpumask_empty(&mask)) before issuing the smp > stop cross call. > > Restarting system. > Unable to handle kernel NULL pointer dereference at virtual address 00000000 > pgd = dda50000 > [00000000] *pgd=9e723831, *pte=00000000, *ppte=00000000 > Internal error: Oops: 80000007 [#1] SMP ARM > Modules linked in: > CPU: 0 Not tainted (3.4.0-00001-gb15b046 #30) > PC is at 0x0 > LR is at smp_send_stop+0x4c/0xe8 > pc : [<00000000>] lr : [<c00188cc>] psr: 60000013 > sp : de7b5e70 ip : 00000000 fp : 00000001 > r10: 00000000 r9 : de7b4000 r8 : c07263d0 > r7 : 00000000 r6 : c06e1294 r5 : 000f4240 r4 : de7b5e74 > r3 : 00000000 r2 : 00000000 r1 : 00000006 r0 : de7b5e74 > Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user > Control: 10c5387d Table: 9da50019 DAC: 00000015 > Process reboot (pid: 2229, stack limit = 0xde7b42f8) > Stack: (0xde7b5e70 to 0xde7b6000) > 5e60: 00000000 00000000 00000000 01234567 > 5e80: de7b4000 c001475c 4321fedc c0052570 0000003e 00000000 c081db78 0000003e > 5ea0: 00000001 00000002 00000002 c00891f0 00000002 dd5ba0ac 00000002 00000000 > 5ec0: dd5ba0ac de7b4000 c009eef4 de7b4000 c00f44dc de7b4000 c00f44dc 00000000 > 5ee0: c0c94d24 de7b4000 00000000 00000000 00000002 00000002 00000000 c00891f0 > 5f00: 00000002 00000000 00000000 c011286c 00000000 dd5ba060 60000013 00000000 > 5f20: dd688d8c 00000000 de7b4000 c06e20f8 dec14760 dec14750 de7b4000 c06e20f8 > 5f40: 00011f10 c01128a0 00000002 00000000 c011286c c00fa014 dd8c3180 de7b4000 > 5f60: c0013380 de508bc0 00000001 60000010 00000001 ef000000 00000001 c0089bfc > 5f80: 00000000 00000001 00000004 00000058 00000000 00000001 00000004 00000058 > 5fa0: c0013428 c0013260 00000000 00000001 fee1dead 28121969 01234567 00000000 > 5fc0: 00000000 00000001 00000004 00000058 00000001 00000001 00000000 00000001 > 5fe0: b6e76200 beba4c90 00009210 b6e76218 60000010 fee1dead 00000000 00000000 > [<c00188cc>] (smp_send_stop+0x4c/0xe8) from [<c001475c>] > (machine_restart+0xc/0x54) > [<c001475c>] (machine_restart+0xc/0x54) from [<c0052570>] > (sys_reboot+0x140/0x204) > [<c0052570>] (sys_reboot+0x140/0x204) from [<c0013260>] > (ret_fast_syscall+0x0/0x3c) > Code: bad PC value > ---[ end trace f5035e8726d1f51b ]--- > > Signed-off-by: Pantelis Antoniou <pa...@antoniou-consulting.com> > Cc: sta...@vger.kernel.org > --- > arch/arm/kernel/smp.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c > index 8f46446..7babc3f 100644 > --- a/arch/arm/kernel/smp.c > +++ b/arch/arm/kernel/smp.c > @@ -590,7 +590,8 @@ void smp_send_stop(void) > > cpumask_copy(&mask, cpu_online_mask); > cpumask_clear_cpu(smp_processor_id(), &mask); > - smp_cross_call(&mask, IPI_CPU_STOP); > + if (!cpumask_empty(&mask)) > + smp_cross_call(&mask, IPI_CPU_STOP); > > /* Wait up to one second for other CPUs to stop */ > timeout = USEC_PER_SEC; > -- > 1.7.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
