summaryrefslogtreecommitdiff
path: root/drivers/crypto/ccp
diff options
context:
space:
mode:
authorTom Lendacky <thomas.lendacky@amd.com>2018-07-03 12:11:33 -0500
committerHerbert Xu <herbert@gondor.apana.org.au>2018-07-13 18:26:48 +0800
commitf426d2b20f1cd63818873593031593e15c3db20b (patch)
tree3aab62b69acd62c556f1fe7a6a79d60fdf969b9a /drivers/crypto/ccp
parent5c324a2ffa06f8b6fda59a77c6807acb9f45cfee (diff)
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: <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>
Diffstat (limited to 'drivers/crypto/ccp')
-rw-r--r--drivers/crypto/ccp/psp-dev.c4
1 files changed, 2 insertions, 2 deletions
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;