From: Tom Lendacky Date: Tue, 3 Jul 2018 17:11:33 +0000 (-0500) Subject: crypto: ccp - Fix command completion detection race X-Git-Tag: microblaze-v5.0-rc1~469^2~68 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=f426d2b20f1cd63818873593031593e15c3db20b;p=linux-2.6-microblaze.git crypto: ccp - Fix command completion detection race The wait_event() function is used to detect command completion. The interrupt handler will set the wait condition variable when the interrupt is triggered. However, the variable used for wait_event() is initialized after the command has been submitted, which can create a race condition with the interrupt handler and result in the wait_event() never returning. Move the initialization of the wait condition variable to just before command submission. Fixes: 200664d5237f ("crypto: ccp: Add Secure Encrypted Virtualization (SEV) command support") Cc: # 4.16.x- Signed-off-by: Tom Lendacky Reviewed-by: Brijesh Singh Acked-by: Gary R Hook Acked-by: Gary R Hook Signed-off-by: Herbert Xu --- diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c index ff478d826d7d..973d683f80ee 100644 --- a/drivers/crypto/ccp/psp-dev.c +++ b/drivers/crypto/ccp/psp-dev.c @@ -84,8 +84,6 @@ done: static void sev_wait_cmd_ioc(struct psp_device *psp, unsigned int *reg) { - psp->sev_int_rcvd = 0; - wait_event(psp->sev_int_queue, psp->sev_int_rcvd); *reg = ioread32(psp->io_regs + PSP_CMDRESP); } @@ -148,6 +146,8 @@ static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret) iowrite32(phys_lsb, psp->io_regs + PSP_CMDBUFF_ADDR_LO); iowrite32(phys_msb, psp->io_regs + PSP_CMDBUFF_ADDR_HI); + psp->sev_int_rcvd = 0; + reg = cmd; reg <<= PSP_CMDRESP_CMD_SHIFT; reg |= PSP_CMDRESP_IOC;