From 5e2fb7c598c6ae2481ca65d3a730b7fc29fdefbb Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 3 Mar 2017 11:59:34 +0000 Subject: [PATCH] hw/misc/imx6_src: Don't crash trying to reset missing CPUs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit 4881658a4b introduced a call to arm_get_cpu_by_id(), and Coverity noticed that we weren't checking that it didn't return NULL (CID 1371652). Normally this won't happen (because all 4 CPUs are expected to exist), but it's possible the user requested fewer CPUs on the command line. Handle this possibility by silently doing nothing, which is the same behaviour as before commit 4881658a4b and also how we handle the other CPU operations (since we ignore the INVALID_PARAM returns from arm_set_cpu_on() and friends). There is a slight behavioural difference to the pre-4881658a4b situation: the "reset this core" bit will remain set rather than not being permitted to be set. The imx6 datasheet is unclear about the behaviour in this odd corner case, so we opt for the simpler code rather than complicated logic to maintain identical behaviour. Signed-off-by: Peter Maydell Message-id: 1488542374-1256-1-git-send-email-peter.maydell@linaro.org Reviewed-by: Alex Bennée --- hw/misc/imx6_src.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/hw/misc/imx6_src.c b/hw/misc/imx6_src.c index edbb756c3652..cfb08710fbd6 100644 --- a/hw/misc/imx6_src.c +++ b/hw/misc/imx6_src.c @@ -143,13 +143,17 @@ static void imx6_defer_clear_reset_bit(int cpuid, unsigned long reset_shift) { struct SRCSCRResetInfo *ri; + CPUState *cpu = arm_get_cpu_by_id(cpuid); + + if (!cpu) { + return; + } ri = g_malloc(sizeof(struct SRCSCRResetInfo)); ri->s = s; ri->reset_bit = reset_shift; - async_run_on_cpu(arm_get_cpu_by_id(cpuid), imx6_clear_reset_bit, - RUN_ON_CPU_HOST_PTR(ri)); + async_run_on_cpu(cpu, imx6_clear_reset_bit, RUN_ON_CPU_HOST_PTR(ri)); }