| Message ID | 20180703171133.3225.66397.stgit@tlendack-t1.amdoffice.net (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Herbert Xu |
| Headers | show |
On 07/03/2018 12:11 PM, Tom Lendacky wrote: > 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> > drivers/crypto/ccp/psp-dev.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c > index ff478d8..973d683 100644 > --- a/drivers/crypto/ccp/psp-dev.c > +++ b/drivers/crypto/ccp/psp-dev.c > @@ -84,8 +84,6 @@ static irqreturn_t psp_irq_handler(int irq, void *data) > > 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; >
On 07/03/2018 12:11 PM, Tom Lendacky wrote: > 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> Acked-by: Gary R Hook <gary.hook@amd.com> > --- > drivers/crypto/ccp/psp-dev.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c > index ff478d8..973d683 100644 > --- a/drivers/crypto/ccp/psp-dev.c > +++ b/drivers/crypto/ccp/psp-dev.c > @@ -84,8 +84,6 @@ static irqreturn_t psp_irq_handler(int irq, void *data) > > 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; >
On 07/05/2018 10:43 AM, Brijesh Singh wrote: > > > On 07/03/2018 12:11 PM, Tom Lendacky wrote: >> 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> > > >> drivers/crypto/ccp/psp-dev.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c >> index ff478d8..973d683 100644 >> --- a/drivers/crypto/ccp/psp-dev.c >> +++ b/drivers/crypto/ccp/psp-dev.c >> @@ -84,8 +84,6 @@ static irqreturn_t psp_irq_handler(int irq, void *data) >> 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; >>
diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c index ff478d8..973d683 100644 --- a/drivers/crypto/ccp/psp-dev.c +++ b/drivers/crypto/ccp/psp-dev.c @@ -84,8 +84,6 @@ static irqreturn_t psp_irq_handler(int irq, void *data) 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;
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> --- drivers/crypto/ccp/psp-dev.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)