6.6-stable review patch. If anyone has any objections, please let me know.
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From: Kathiravan Thirumoorthy quic_kathirav@quicinc.com
commit 3337a6fea25370d3d244ec6bb38c71ee86fcf837 upstream.
Per the "SMC calling convention specification", the 64-bit calling convention can only be used when the client is 64-bit. Whereas the 32-bit calling convention can be used by either a 32-bit or a 64-bit client.
Currently during SCM probe, irrespective of the client, 64-bit calling convention is made, which is incorrect and may lead to the undefined behaviour when the client is 32-bit. Let's fix it.
Cc: stable@vger.kernel.org Fixes: 9a434cee773a ("firmware: qcom_scm: Dynamically support SMCCC and legacy conventions") Reviewed-By: Elliot Berman quic_eberman@quicinc.com Signed-off-by: Kathiravan Thirumoorthy quic_kathirav@quicinc.com Link: https://lore.kernel.org/r/20230925-scm-v3-1-8790dff6a749@quicinc.com Signed-off-by: Bjorn Andersson andersson@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/firmware/qcom_scm.c | 7 +++++++ 1 file changed, 7 insertions(+)
--- a/drivers/firmware/qcom_scm.c +++ b/drivers/firmware/qcom_scm.c @@ -168,6 +168,12 @@ static enum qcom_scm_convention __get_co return qcom_scm_convention;
/* + * Per the "SMC calling convention specification", the 64-bit calling + * convention can only be used when the client is 64-bit, otherwise + * system will encounter the undefined behaviour. + */ +#if IS_ENABLED(CONFIG_ARM64) + /* * Device isn't required as there is only one argument - no device * needed to dma_map_single to secure world */ @@ -187,6 +193,7 @@ static enum qcom_scm_convention __get_co forced = true; goto found; } +#endif
probed_convention = SMC_CONVENTION_ARM_32; ret = __scm_smc_call(NULL, &desc, probed_convention, &res, true);