3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Markos Chandras <markos.chandras@xxxxxxxxxx> commit ab6c15bc6620ebe220970cc040b29bcb2757f373 upstream. Previously, the lower limit for the MIPS SC initialization loop was set incorrectly allowing one extra loop leading to writes beyond the MSC ioremap'd space. More precisely, the value of the 'imp' in the last loop increased beyond the msc_irqmap_t boundaries and as a result of which, the 'n' variable was loaded with an incorrect value. This value was used later on to calculate the offset in the MSC01_IC_SUP which led to random crashes like the following one: CPU 0 Unable to handle kernel paging request at virtual address e75c0200, epc == 8058dba4, ra == 8058db90 [...] Call Trace: [<8058dba4>] init_msc_irqs+0x104/0x154 [<8058b5bc>] arch_init_irq+0xd8/0x154 [<805897b0>] start_kernel+0x220/0x36c Kernel panic - not syncing: Attempted to kill the idle task! This patch fixes the problem Signed-off-by: Markos Chandras <markos.chandras@xxxxxxxxxx> Reviewed-by: James Hogan <james.hogan@xxxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxx Patchwork: https://patchwork.linux-mips.org/patch/7118/ Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/mips/kernel/irq-msc01.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/mips/kernel/irq-msc01.c +++ b/arch/mips/kernel/irq-msc01.c @@ -131,7 +131,7 @@ void __init init_msc_irqs(unsigned long board_bind_eic_interrupt = &msc_bind_eic_interrupt; - for (; nirq >= 0; nirq--, imp++) { + for (; nirq > 0; nirq--, imp++) { int n = imp->im_irq; switch (imp->im_type) {
