diff options
| author | Tom Lendacky <thomas.lendacky@amd.com> | 2018-07-03 12:11:33 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-17 21:03:48 +0200 |
| commit | f2ccfbe47112074bcaeeb11e61f9b51f354f33d9 (patch) | |
| tree | 925dae4fb48c5edc2a8d8943c12adbef0fb77b0d | |
| parent | 93aff32d53fd3d1377414855f7275cab16fbb31e (diff) | |
| download | linux-f2ccfbe47112074bcaeeb11e61f9b51f354f33d9.tar.gz | |
crypto: ccp - Fix command completion detection race
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>
| -rw-r--r-- | drivers/crypto/ccp/psp-dev.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c index 603db3d45b1a6..051b8c6bae647 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; |