* [PATCH net-next v3 1/2] pktgen: Automate flag enumeration for unknown flag handling
@ 2023-09-15 12:23 Liang Chen
2023-09-15 12:23 ` [PATCH net-next v3 2/2] pktgen: Introducing 'SHARED' flag for testing with non-shared skb Liang Chen
0 siblings, 1 reply; 4+ messages in thread
From: Liang Chen @ 2023-09-15 12:23 UTC (permalink / raw)
To: davem, edumazet, kuba, pabeni, benjamin.poirier; +Cc: netdev, liangchen.linux
When specifying an unknown flag, it will print all available flags.
Currently, these flags are provided as fixed strings, which requires
manual updates when flags change. Replacing it with automated flag
enumeration.
Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
---
net/core/pktgen.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index f56b8d697014..ffd659dbd6c3 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -1318,6 +1318,7 @@ static ssize_t pktgen_if_write(struct file *file,
return count;
}
if (!strcmp(name, "flag")) {
+ unsigned int n;
__u32 flag;
char f[32];
bool disable = false;
@@ -1339,18 +1340,19 @@ static ssize_t pktgen_if_write(struct file *file,
else
pkt_dev->flags |= flag;
} else {
- sprintf(pg_result,
- "Flag -:%s:- unknown\nAvailable flags, (prepend ! to un-set flag):\n%s",
- f,
- "IPSRC_RND, IPDST_RND, UDPSRC_RND, UDPDST_RND, "
- "MACSRC_RND, MACDST_RND, TXSIZE_RND, IPV6, "
- "MPLS_RND, VID_RND, SVID_RND, FLOW_SEQ, "
- "QUEUE_MAP_RND, QUEUE_MAP_CPU, UDPCSUM, "
- "NO_TIMESTAMP, "
-#ifdef CONFIG_XFRM
- "IPSEC, "
+ pg_result += sprintf(pg_result,
+ "Flag -:%s:- unknown\n%s", f,
+ "Available flags, (prepend ! to un-set flag):\n");
+ for (n = 0; n < NR_PKT_FLAGS; n++) {
+#ifndef CONFIG_XFRM
+ if (!strcmp("IPSEC", pkt_flag_names[n]))
+ continue;
#endif
- "NODE_ALLOC\n");
+ pg_result += sprintf(pg_result, "%s, ", pkt_flag_names[n]);
+ }
+ /* Remove the comma and whitespace at the end */
+ *(pg_result - 2) = '\n';
+
return count;
}
sprintf(pg_result, "OK: flags=0x%x", pkt_dev->flags);
--
2.40.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH net-next v3 2/2] pktgen: Introducing 'SHARED' flag for testing with non-shared skb
2023-09-15 12:23 [PATCH net-next v3 1/2] pktgen: Automate flag enumeration for unknown flag handling Liang Chen
@ 2023-09-15 12:23 ` Liang Chen
2023-09-16 0:45 ` Benjamin Poirier
0 siblings, 1 reply; 4+ messages in thread
From: Liang Chen @ 2023-09-15 12:23 UTC (permalink / raw)
To: davem, edumazet, kuba, pabeni, benjamin.poirier; +Cc: netdev, liangchen.linux
Currently, skbs generated by pktgen always have their reference count
incremented before transmission, causing their reference count to be
always greater than 1, leading to two issues:
1. Only the code paths for shared skbs can be tested.
2. In certain situations, skbs can only be released by pktgen.
To enhance testing comprehensiveness, we are introducing the "SHARED"
flag to indicate whether an SKB is shared. This flag is enabled by
default, aligning with the current behavior. However, disabling this
flag allows skbs with a reference count of 1 to be transmitted.
So we can test non-shared skbs and code paths where skbs are released
within the stack.
Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
---
Changes from v2:
- Lifted the check on 'count' when 'not shared' is configured.
- Fixed a use-after-free problem when sending failed
---
Documentation/networking/pktgen.rst | 12 ++++++++
net/core/pktgen.c | 47 ++++++++++++++++++++++++-----
2 files changed, 51 insertions(+), 8 deletions(-)
diff --git a/Documentation/networking/pktgen.rst b/Documentation/networking/pktgen.rst
index 1225f0f63ff0..c945218946e1 100644
--- a/Documentation/networking/pktgen.rst
+++ b/Documentation/networking/pktgen.rst
@@ -178,6 +178,7 @@ Examples::
IPSEC # IPsec encapsulation (needs CONFIG_XFRM)
NODE_ALLOC # node specific memory allocation
NO_TIMESTAMP # disable timestamping
+ SHARED # enable shared SKB
pgset 'flag ![name]' Clear a flag to determine behaviour.
Note that you might need to use single quote in
interactive mode, so that your shell wouldn't expand
@@ -288,6 +289,16 @@ To avoid breaking existing testbed scripts for using AH type and tunnel mode,
you can use "pgset spi SPI_VALUE" to specify which transformation mode
to employ.
+Disable shared SKB
+==================
+By default, SKBs sent by pktgen are shared (user count > 1).
+To test with non-shared SKBs, remove the "SHARED" flag by simply setting::
+
+ pg_set "flag !SHARED"
+
+However, if the "clone_skb" or "burst" parameters are configured, the skb
+still needs to be held by pktgen for further access. Hence the skb must be
+shared.
Current commands and configuration options
==========================================
@@ -357,6 +368,7 @@ Current commands and configuration options
IPSEC
NODE_ALLOC
NO_TIMESTAMP
+ SHARED
spi (ipsec)
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index ffd659dbd6c3..5cc69feec7d7 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -200,6 +200,7 @@
pf(VID_RND) /* Random VLAN ID */ \
pf(SVID_RND) /* Random SVLAN ID */ \
pf(NODE) /* Node memory alloc*/ \
+ pf(SHARED) /* Shared SKB */ \
#define pf(flag) flag##_SHIFT,
enum pkt_flags {
@@ -1198,7 +1199,8 @@ static ssize_t pktgen_if_write(struct file *file,
((pkt_dev->xmit_mode == M_NETIF_RECEIVE) ||
!(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))
return -ENOTSUPP;
- if (value > 0 && pkt_dev->n_imix_entries > 0)
+ if (value > 0 && (pkt_dev->n_imix_entries > 0 ||
+ !(pkt_dev->flags & F_SHARED)))
return -EINVAL;
i += len;
@@ -1257,6 +1259,10 @@ static ssize_t pktgen_if_write(struct file *file,
((pkt_dev->xmit_mode == M_START_XMIT) &&
(!(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))))
return -ENOTSUPP;
+
+ if ((value > 1) && !(pkt_dev->flags & F_SHARED))
+ return -EINVAL;
+
pkt_dev->burst = value < 1 ? 1 : value;
sprintf(pg_result, "OK: burst=%u", pkt_dev->burst);
return count;
@@ -1335,10 +1341,18 @@ static ssize_t pktgen_if_write(struct file *file,
flag = pktgen_read_flag(f, &disable);
if (flag) {
- if (disable)
+ if (disable) {
+ /* If "clone_skb", or "burst" parameters are
+ * configured, it means that the skb still needs to be
+ * referenced by the pktgen, so the skb must be shared.
+ */
+ if (flag == F_SHARED && (pkt_dev->clone_skb ||
+ pkt_dev->burst > 1))
+ return -EINVAL;
pkt_dev->flags &= ~flag;
- else
+ } else {
pkt_dev->flags |= flag;
+ }
} else {
pg_result += sprintf(pg_result,
"Flag -:%s:- unknown\n%s", f,
@@ -3485,7 +3499,8 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
if (pkt_dev->xmit_mode == M_NETIF_RECEIVE) {
skb = pkt_dev->skb;
skb->protocol = eth_type_trans(skb, skb->dev);
- refcount_add(burst, &skb->users);
+ if (pkt_dev->flags & F_SHARED)
+ refcount_add(burst, &skb->users);
local_bh_disable();
do {
ret = netif_receive_skb(skb);
@@ -3493,6 +3508,10 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
pkt_dev->errors++;
pkt_dev->sofar++;
pkt_dev->seq_num++;
+ if (unlikely(!(pkt_dev->flags & F_SHARED))) {
+ pkt_dev->skb = NULL;
+ break;
+ }
if (refcount_read(&skb->users) != burst) {
/* skb was queued by rps/rfs or taps,
* so cannot reuse this skb
@@ -3511,9 +3530,14 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
goto out; /* Skips xmit_mode M_START_XMIT */
} else if (pkt_dev->xmit_mode == M_QUEUE_XMIT) {
local_bh_disable();
- refcount_inc(&pkt_dev->skb->users);
+ if (pkt_dev->flags & F_SHARED)
+ refcount_inc(&pkt_dev->skb->users);
ret = dev_queue_xmit(pkt_dev->skb);
+
+ if (!(pkt_dev->flags & F_SHARED) && dev_xmit_complete(ret))
+ pkt_dev->skb = NULL;
+
switch (ret) {
case NET_XMIT_SUCCESS:
pkt_dev->sofar++;
@@ -3551,11 +3575,15 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
pkt_dev->last_ok = 0;
goto unlock;
}
- refcount_add(burst, &pkt_dev->skb->users);
+ if (pkt_dev->flags & F_SHARED)
+ refcount_add(burst, &pkt_dev->skb->users);
xmit_more:
ret = netdev_start_xmit(pkt_dev->skb, odev, txq, --burst > 0);
+ if (!(pkt_dev->flags & F_SHARED) && dev_xmit_complete(ret))
+ pkt_dev->skb = NULL;
+
switch (ret) {
case NETDEV_TX_OK:
pkt_dev->last_ok = 1;
@@ -3577,7 +3605,8 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
fallthrough;
case NETDEV_TX_BUSY:
/* Retry it next time */
- refcount_dec(&(pkt_dev->skb->users));
+ if (!(pkt_dev->flags & F_SHARED))
+ refcount_dec(&(pkt_dev->skb->users));
pkt_dev->last_ok = 0;
}
if (unlikely(burst))
@@ -3590,7 +3619,8 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
/* If pkt_dev->count is zero, then run forever */
if ((pkt_dev->count != 0) && (pkt_dev->sofar >= pkt_dev->count)) {
- pktgen_wait_for_skb(pkt_dev);
+ if (pkt_dev->skb)
+ pktgen_wait_for_skb(pkt_dev);
/* Done with this */
pktgen_stop_device(pkt_dev);
@@ -3773,6 +3803,7 @@ static int pktgen_add_device(struct pktgen_thread *t, const char *ifname)
pkt_dev->svlan_id = 0xffff;
pkt_dev->burst = 1;
pkt_dev->node = NUMA_NO_NODE;
+ pkt_dev->flags = F_SHARED; /* SKB shared by default */
err = pktgen_setup_dev(t->net, pkt_dev, ifname);
if (err)
--
2.40.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH net-next v3 2/2] pktgen: Introducing 'SHARED' flag for testing with non-shared skb
2023-09-15 12:23 ` [PATCH net-next v3 2/2] pktgen: Introducing 'SHARED' flag for testing with non-shared skb Liang Chen
@ 2023-09-16 0:45 ` Benjamin Poirier
2023-09-16 3:20 ` Liang Chen
0 siblings, 1 reply; 4+ messages in thread
From: Benjamin Poirier @ 2023-09-16 0:45 UTC (permalink / raw)
To: Liang Chen; +Cc: davem, edumazet, kuba, pabeni, netdev
On 2023-09-15 20:23 +0800, Liang Chen wrote:
> Currently, skbs generated by pktgen always have their reference count
> incremented before transmission, causing their reference count to be
> always greater than 1, leading to two issues:
> 1. Only the code paths for shared skbs can be tested.
> 2. In certain situations, skbs can only be released by pktgen.
> To enhance testing comprehensiveness, we are introducing the "SHARED"
> flag to indicate whether an SKB is shared. This flag is enabled by
> default, aligning with the current behavior. However, disabling this
> flag allows skbs with a reference count of 1 to be transmitted.
> So we can test non-shared skbs and code paths where skbs are released
> within the stack.
>
> Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
>
> ---
> Changes from v2:
> - Lifted the check on 'count' when 'not shared' is configured.
> - Fixed a use-after-free problem when sending failed
> ---
> Documentation/networking/pktgen.rst | 12 ++++++++
> net/core/pktgen.c | 47 ++++++++++++++++++++++++-----
> 2 files changed, 51 insertions(+), 8 deletions(-)
>
> diff --git a/Documentation/networking/pktgen.rst b/Documentation/networking/pktgen.rst
> index 1225f0f63ff0..c945218946e1 100644
> --- a/Documentation/networking/pktgen.rst
> +++ b/Documentation/networking/pktgen.rst
> @@ -178,6 +178,7 @@ Examples::
> IPSEC # IPsec encapsulation (needs CONFIG_XFRM)
> NODE_ALLOC # node specific memory allocation
> NO_TIMESTAMP # disable timestamping
> + SHARED # enable shared SKB
> pgset 'flag ![name]' Clear a flag to determine behaviour.
> Note that you might need to use single quote in
> interactive mode, so that your shell wouldn't expand
> @@ -288,6 +289,16 @@ To avoid breaking existing testbed scripts for using AH type and tunnel mode,
> you can use "pgset spi SPI_VALUE" to specify which transformation mode
> to employ.
>
> +Disable shared SKB
> +==================
> +By default, SKBs sent by pktgen are shared (user count > 1).
> +To test with non-shared SKBs, remove the "SHARED" flag by simply setting::
> +
> + pg_set "flag !SHARED"
> +
> +However, if the "clone_skb" or "burst" parameters are configured, the skb
> +still needs to be held by pktgen for further access. Hence the skb must be
> +shared.
>
> Current commands and configuration options
> ==========================================
> @@ -357,6 +368,7 @@ Current commands and configuration options
> IPSEC
> NODE_ALLOC
> NO_TIMESTAMP
> + SHARED
>
> spi (ipsec)
>
> diff --git a/net/core/pktgen.c b/net/core/pktgen.c
> index ffd659dbd6c3..5cc69feec7d7 100644
> --- a/net/core/pktgen.c
> +++ b/net/core/pktgen.c
> @@ -200,6 +200,7 @@
> pf(VID_RND) /* Random VLAN ID */ \
> pf(SVID_RND) /* Random SVLAN ID */ \
> pf(NODE) /* Node memory alloc*/ \
> + pf(SHARED) /* Shared SKB */ \
>
> #define pf(flag) flag##_SHIFT,
> enum pkt_flags {
> @@ -1198,7 +1199,8 @@ static ssize_t pktgen_if_write(struct file *file,
> ((pkt_dev->xmit_mode == M_NETIF_RECEIVE) ||
> !(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))
> return -ENOTSUPP;
> - if (value > 0 && pkt_dev->n_imix_entries > 0)
> + if (value > 0 && (pkt_dev->n_imix_entries > 0 ||
> + !(pkt_dev->flags & F_SHARED)))
> return -EINVAL;
>
> i += len;
> @@ -1257,6 +1259,10 @@ static ssize_t pktgen_if_write(struct file *file,
> ((pkt_dev->xmit_mode == M_START_XMIT) &&
> (!(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))))
> return -ENOTSUPP;
> +
> + if ((value > 1) && !(pkt_dev->flags & F_SHARED))
> + return -EINVAL;
> +
Make sure to run checkpatch and check the patchwork results. There are
some points to correct:
https://patchwork.kernel.org/project/netdevbpf/patch/20230915122317.100390-2-liangchen.linux@gmail.com/
> pkt_dev->burst = value < 1 ? 1 : value;
> sprintf(pg_result, "OK: burst=%u", pkt_dev->burst);
> return count;
> @@ -1335,10 +1341,18 @@ static ssize_t pktgen_if_write(struct file *file,
> flag = pktgen_read_flag(f, &disable);
>
> if (flag) {
> - if (disable)
> + if (disable) {
> + /* If "clone_skb", or "burst" parameters are
> + * configured, it means that the skb still needs to be
> + * referenced by the pktgen, so the skb must be shared.
> + */
> + if (flag == F_SHARED && (pkt_dev->clone_skb ||
> + pkt_dev->burst > 1))
> + return -EINVAL;
> pkt_dev->flags &= ~flag;
> - else
> + } else {
> pkt_dev->flags |= flag;
> + }
> } else {
> pg_result += sprintf(pg_result,
> "Flag -:%s:- unknown\n%s", f,
> @@ -3485,7 +3499,8 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
> if (pkt_dev->xmit_mode == M_NETIF_RECEIVE) {
> skb = pkt_dev->skb;
> skb->protocol = eth_type_trans(skb, skb->dev);
> - refcount_add(burst, &skb->users);
> + if (pkt_dev->flags & F_SHARED)
> + refcount_add(burst, &skb->users);
> local_bh_disable();
> do {
> ret = netif_receive_skb(skb);
> @@ -3493,6 +3508,10 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
> pkt_dev->errors++;
> pkt_dev->sofar++;
> pkt_dev->seq_num++;
> + if (unlikely(!(pkt_dev->flags & F_SHARED))) {
> + pkt_dev->skb = NULL;
> + break;
> + }
> if (refcount_read(&skb->users) != burst) {
> /* skb was queued by rps/rfs or taps,
> * so cannot reuse this skb
> @@ -3511,9 +3530,14 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
> goto out; /* Skips xmit_mode M_START_XMIT */
> } else if (pkt_dev->xmit_mode == M_QUEUE_XMIT) {
> local_bh_disable();
> - refcount_inc(&pkt_dev->skb->users);
> + if (pkt_dev->flags & F_SHARED)
> + refcount_inc(&pkt_dev->skb->users);
>
> ret = dev_queue_xmit(pkt_dev->skb);
> +
> + if (!(pkt_dev->flags & F_SHARED) && dev_xmit_complete(ret))
> + pkt_dev->skb = NULL;
> +
> switch (ret) {
> case NET_XMIT_SUCCESS:
> pkt_dev->sofar++;
> @@ -3551,11 +3575,15 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
> pkt_dev->last_ok = 0;
> goto unlock;
> }
> - refcount_add(burst, &pkt_dev->skb->users);
> + if (pkt_dev->flags & F_SHARED)
> + refcount_add(burst, &pkt_dev->skb->users);
>
> xmit_more:
> ret = netdev_start_xmit(pkt_dev->skb, odev, txq, --burst > 0);
>
> + if (!(pkt_dev->flags & F_SHARED) && dev_xmit_complete(ret))
> + pkt_dev->skb = NULL;
> +
> switch (ret) {
> case NETDEV_TX_OK:
> pkt_dev->last_ok = 1;
> @@ -3577,7 +3605,8 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
> fallthrough;
> case NETDEV_TX_BUSY:
> /* Retry it next time */
> - refcount_dec(&(pkt_dev->skb->users));
> + if (!(pkt_dev->flags & F_SHARED))
> + refcount_dec(&(pkt_dev->skb->users));
With "flag !SHARED", this leads to a refcount underflow if the driver
returns NETDEV_TX_BUSY.
It looks like the condition is inverted, no?
I tested it by hacking e1000_xmit_frame() to return NETDEV_TX_BUSY right
at the beginning.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net-next v3 2/2] pktgen: Introducing 'SHARED' flag for testing with non-shared skb
2023-09-16 0:45 ` Benjamin Poirier
@ 2023-09-16 3:20 ` Liang Chen
0 siblings, 0 replies; 4+ messages in thread
From: Liang Chen @ 2023-09-16 3:20 UTC (permalink / raw)
To: Benjamin Poirier; +Cc: davem, edumazet, kuba, pabeni, netdev
On Sat, Sep 16, 2023 at 8:45 AM Benjamin Poirier
<benjamin.poirier@gmail.com> wrote:
>
> On 2023-09-15 20:23 +0800, Liang Chen wrote:
> > Currently, skbs generated by pktgen always have their reference count
> > incremented before transmission, causing their reference count to be
> > always greater than 1, leading to two issues:
> > 1. Only the code paths for shared skbs can be tested.
> > 2. In certain situations, skbs can only be released by pktgen.
> > To enhance testing comprehensiveness, we are introducing the "SHARED"
> > flag to indicate whether an SKB is shared. This flag is enabled by
> > default, aligning with the current behavior. However, disabling this
> > flag allows skbs with a reference count of 1 to be transmitted.
> > So we can test non-shared skbs and code paths where skbs are released
> > within the stack.
> >
> > Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
> >
> > ---
> > Changes from v2:
> > - Lifted the check on 'count' when 'not shared' is configured.
> > - Fixed a use-after-free problem when sending failed
> > ---
> > Documentation/networking/pktgen.rst | 12 ++++++++
> > net/core/pktgen.c | 47 ++++++++++++++++++++++++-----
> > 2 files changed, 51 insertions(+), 8 deletions(-)
> >
> > diff --git a/Documentation/networking/pktgen.rst b/Documentation/networking/pktgen.rst
> > index 1225f0f63ff0..c945218946e1 100644
> > --- a/Documentation/networking/pktgen.rst
> > +++ b/Documentation/networking/pktgen.rst
> > @@ -178,6 +178,7 @@ Examples::
> > IPSEC # IPsec encapsulation (needs CONFIG_XFRM)
> > NODE_ALLOC # node specific memory allocation
> > NO_TIMESTAMP # disable timestamping
> > + SHARED # enable shared SKB
> > pgset 'flag ![name]' Clear a flag to determine behaviour.
> > Note that you might need to use single quote in
> > interactive mode, so that your shell wouldn't expand
> > @@ -288,6 +289,16 @@ To avoid breaking existing testbed scripts for using AH type and tunnel mode,
> > you can use "pgset spi SPI_VALUE" to specify which transformation mode
> > to employ.
> >
> > +Disable shared SKB
> > +==================
> > +By default, SKBs sent by pktgen are shared (user count > 1).
> > +To test with non-shared SKBs, remove the "SHARED" flag by simply setting::
> > +
> > + pg_set "flag !SHARED"
> > +
> > +However, if the "clone_skb" or "burst" parameters are configured, the skb
> > +still needs to be held by pktgen for further access. Hence the skb must be
> > +shared.
> >
> > Current commands and configuration options
> > ==========================================
> > @@ -357,6 +368,7 @@ Current commands and configuration options
> > IPSEC
> > NODE_ALLOC
> > NO_TIMESTAMP
> > + SHARED
> >
> > spi (ipsec)
> >
> > diff --git a/net/core/pktgen.c b/net/core/pktgen.c
> > index ffd659dbd6c3..5cc69feec7d7 100644
> > --- a/net/core/pktgen.c
> > +++ b/net/core/pktgen.c
> > @@ -200,6 +200,7 @@
> > pf(VID_RND) /* Random VLAN ID */ \
> > pf(SVID_RND) /* Random SVLAN ID */ \
> > pf(NODE) /* Node memory alloc*/ \
> > + pf(SHARED) /* Shared SKB */ \
> >
> > #define pf(flag) flag##_SHIFT,
> > enum pkt_flags {
> > @@ -1198,7 +1199,8 @@ static ssize_t pktgen_if_write(struct file *file,
> > ((pkt_dev->xmit_mode == M_NETIF_RECEIVE) ||
> > !(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))
> > return -ENOTSUPP;
> > - if (value > 0 && pkt_dev->n_imix_entries > 0)
> > + if (value > 0 && (pkt_dev->n_imix_entries > 0 ||
> > + !(pkt_dev->flags & F_SHARED)))
> > return -EINVAL;
> >
> > i += len;
> > @@ -1257,6 +1259,10 @@ static ssize_t pktgen_if_write(struct file *file,
> > ((pkt_dev->xmit_mode == M_START_XMIT) &&
> > (!(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))))
> > return -ENOTSUPP;
> > +
> > + if ((value > 1) && !(pkt_dev->flags & F_SHARED))
> > + return -EINVAL;
> > +
>
> Make sure to run checkpatch and check the patchwork results. There are
> some points to correct:
> https://patchwork.kernel.org/project/netdevbpf/patch/20230915122317.100390-2-liangchen.linux@gmail.com/
>
Sure. Will do.
> > pkt_dev->burst = value < 1 ? 1 : value;
> > sprintf(pg_result, "OK: burst=%u", pkt_dev->burst);
> > return count;
> > @@ -1335,10 +1341,18 @@ static ssize_t pktgen_if_write(struct file *file,
> > flag = pktgen_read_flag(f, &disable);
> >
> > if (flag) {
> > - if (disable)
> > + if (disable) {
> > + /* If "clone_skb", or "burst" parameters are
> > + * configured, it means that the skb still needs to be
> > + * referenced by the pktgen, so the skb must be shared.
> > + */
> > + if (flag == F_SHARED && (pkt_dev->clone_skb ||
> > + pkt_dev->burst > 1))
> > + return -EINVAL;
> > pkt_dev->flags &= ~flag;
> > - else
> > + } else {
> > pkt_dev->flags |= flag;
> > + }
> > } else {
> > pg_result += sprintf(pg_result,
> > "Flag -:%s:- unknown\n%s", f,
> > @@ -3485,7 +3499,8 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
> > if (pkt_dev->xmit_mode == M_NETIF_RECEIVE) {
> > skb = pkt_dev->skb;
> > skb->protocol = eth_type_trans(skb, skb->dev);
> > - refcount_add(burst, &skb->users);
> > + if (pkt_dev->flags & F_SHARED)
> > + refcount_add(burst, &skb->users);
> > local_bh_disable();
> > do {
> > ret = netif_receive_skb(skb);
> > @@ -3493,6 +3508,10 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
> > pkt_dev->errors++;
> > pkt_dev->sofar++;
> > pkt_dev->seq_num++;
> > + if (unlikely(!(pkt_dev->flags & F_SHARED))) {
> > + pkt_dev->skb = NULL;
> > + break;
> > + }
> > if (refcount_read(&skb->users) != burst) {
> > /* skb was queued by rps/rfs or taps,
> > * so cannot reuse this skb
> > @@ -3511,9 +3530,14 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
> > goto out; /* Skips xmit_mode M_START_XMIT */
> > } else if (pkt_dev->xmit_mode == M_QUEUE_XMIT) {
> > local_bh_disable();
> > - refcount_inc(&pkt_dev->skb->users);
> > + if (pkt_dev->flags & F_SHARED)
> > + refcount_inc(&pkt_dev->skb->users);
> >
> > ret = dev_queue_xmit(pkt_dev->skb);
> > +
> > + if (!(pkt_dev->flags & F_SHARED) && dev_xmit_complete(ret))
> > + pkt_dev->skb = NULL;
> > +
> > switch (ret) {
> > case NET_XMIT_SUCCESS:
> > pkt_dev->sofar++;
> > @@ -3551,11 +3575,15 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
> > pkt_dev->last_ok = 0;
> > goto unlock;
> > }
> > - refcount_add(burst, &pkt_dev->skb->users);
> > + if (pkt_dev->flags & F_SHARED)
> > + refcount_add(burst, &pkt_dev->skb->users);
> >
> > xmit_more:
> > ret = netdev_start_xmit(pkt_dev->skb, odev, txq, --burst > 0);
> >
> > + if (!(pkt_dev->flags & F_SHARED) && dev_xmit_complete(ret))
> > + pkt_dev->skb = NULL;
> > +
> > switch (ret) {
> > case NETDEV_TX_OK:
> > pkt_dev->last_ok = 1;
> > @@ -3577,7 +3605,8 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
> > fallthrough;
> > case NETDEV_TX_BUSY:
> > /* Retry it next time */
> > - refcount_dec(&(pkt_dev->skb->users));
> > + if (!(pkt_dev->flags & F_SHARED))
> > + refcount_dec(&(pkt_dev->skb->users));
>
> With "flag !SHARED", this leads to a refcount underflow if the driver
> returns NETDEV_TX_BUSY.
>
> It looks like the condition is inverted, no?
>
Yeah, my bad. Sorry about that. Thanks!
> I tested it by hacking e1000_xmit_frame() to return NETDEV_TX_BUSY right
> at the beginning.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-09-16 3:20 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-09-15 12:23 [PATCH net-next v3 1/2] pktgen: Automate flag enumeration for unknown flag handling Liang Chen
2023-09-15 12:23 ` [PATCH net-next v3 2/2] pktgen: Introducing 'SHARED' flag for testing with non-shared skb Liang Chen
2023-09-16 0:45 ` Benjamin Poirier
2023-09-16 3:20 ` Liang Chen
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