2022-01-30 14:34:32

by Wang, Haiyue

Subject: [PATCH v1] gve: fix the wrong AdminQ buffer queue index check

The 'tail' and 'head' are 'unsigned int' type free-running count, when
'head' is overflow, the 'int i (= tail) < u32 head' will be false:

Only '- loop 0: idx = 63' result is shown, so it needs to use 'int' type
to compare, it can handle the overflow correctly.

typedef uint32_t u32;

int main()
{
u32 tail, head;
int stail, shead;
int i, loop;

tail = 0xffffffff;
head = 0x00000000;

for (i = tail, loop = 0; i < head; i++) {
unsigned int idx = i & 63;

printf("+ loop %d: idx = %u\n", loop++, idx);
}

stail = tail;
shead = head;
for (i = stail, loop = 0; i < shead; i++) {
unsigned int idx = i & 63;

printf("- loop %d: idx = %u\n", loop++, idx);
}

return 0;
}

Fixes: 5cdad90de62c ("gve: Batch AQ commands for creating and destroying queues.")

Signed-off-by: Haiyue Wang <[email protected]>
---
drivers/net/ethernet/google/gve/gve_adminq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/google/gve/gve_adminq.c b/drivers/net/ethernet/google/gve/gve_adminq.c
index 2ad7f57f7e5b..f7621ab672b9 100644
--- a/drivers/net/ethernet/google/gve/gve_adminq.c
+++ b/drivers/net/ethernet/google/gve/gve_adminq.c
@@ -301,7 +301,7 @@ static int gve_adminq_parse_err(struct gve_priv *priv, u32 status)
*/
static int gve_adminq_kick_and_wait(struct gve_priv *priv)
{
- u32 tail, head;
+ int tail, head;
int i;

tail = ioread32be(&priv->reg_bar0->adminq_event_counter);
--
2.35.0

2022-01-31 07:26:25

by Wang, Haiyue

Subject: [PATCH v2] gve: fix the wrong AdminQ buffer queue index check

The 'tail' and 'head' are 'unsigned int' type free-running count, when
'head' is overflow, the 'int i (= tail) < u32 head' will be false:

Only '- loop 0: idx = 63' result is shown, so it needs to use 'int' type
to compare, it can handle the overflow correctly.

typedef uint32_t u32;

int main()
{
u32 tail, head;
int stail, shead;
int i, loop;

tail = 0xffffffff;
head = 0x00000000;

for (i = tail, loop = 0; i < head; i++) {
unsigned int idx = i & 63;

printf("+ loop %d: idx = %u\n", loop++, idx);
}

stail = tail;
shead = head;
for (i = stail, loop = 0; i < shead; i++) {
unsigned int idx = i & 63;

printf("- loop %d: idx = %u\n", loop++, idx);
}

return 0;
}

Fixes: 5cdad90de62c ("gve: Batch AQ commands for creating and destroying queues.")
Signed-off-by: Haiyue Wang <[email protected]>
---
v2: Fix empty lines surround the Fixes tag
---
drivers/net/ethernet/google/gve/gve_adminq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/google/gve/gve_adminq.c b/drivers/net/ethernet/google/gve/gve_adminq.c
index 2ad7f57f7e5b..f7621ab672b9 100644
--- a/drivers/net/ethernet/google/gve/gve_adminq.c
+++ b/drivers/net/ethernet/google/gve/gve_adminq.c
@@ -301,7 +301,7 @@ static int gve_adminq_parse_err(struct gve_priv *priv, u32 status)
*/
static int gve_adminq_kick_and_wait(struct gve_priv *priv)
{
- u32 tail, head;
+ int tail, head;
int i;

tail = ioread32be(&priv->reg_bar0->adminq_event_counter);
--
2.35.0

2022-01-31 11:11:21

by patchwork-bot+netdevbpf

Subject: Re: [PATCH v2] gve: fix the wrong AdminQ buffer queue index check

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller <[email protected]>:

On Fri, 28 Jan 2022 18:47:14 +0800 you wrote:
> The 'tail' and 'head' are 'unsigned int' type free-running count, when
> 'head' is overflow, the 'int i (= tail) < u32 head' will be false:
>
> Only '- loop 0: idx = 63' result is shown, so it needs to use 'int' type
> to compare, it can handle the overflow correctly.
>
> typedef uint32_t u32;
>
> [...]

Here is the summary with links:
- [v2] gve: fix the wrong AdminQ buffer queue index check
https://git.kernel.org/netdev/net/c/1f84a9450d75

You are awesome, thank you!
--
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