Re: [PATCH v1 1/5] crypto: ccp: Fix command completion detection race
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: # 4.16.x-
Signed-off-by: Tom Lendacky
---
Reviewed-by: Brijesh Singh
Acked-by: Gary R Hook
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;
Re: [PATCH v1 1/5] crypto: ccp: Fix command completion detection race
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: # 4.16.x-
Signed-off-by: Tom Lendacky
Acked-by: Gary R Hook
---
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;
Re: [PATCH v1 1/5] crypto: ccp: Fix command completion detection race
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: # 4.16.x-
Signed-off-by: Tom Lendacky
---
Reviewed-by: Brijesh Singh
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;
[PATCH v1 1/5] 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
---
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;
