4.18-stable review patch. If anyone has any objections, please let me know.
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From: Tom Lendacky thomas.lendacky@amd.com
commit f426d2b20f1cd63818873593031593e15c3db20b upstream.
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: stable@vger.kernel.org # 4.16.x- Signed-off-by: Tom Lendacky thomas.lendacky@amd.com Reviewed-by: Brijesh Singh brijesh.singh@amd.com Acked-by: Gary R Hook gary.hook@amd.com Acked-by: Gary R Hook gary.hook@amd.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/crypto/ccp/psp-dev.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- 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, 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;