Re: [PATCH net v2] net/sched: act_gact: properly init 'goto chain'

2018-10-20 Thread Davide Caratti 
hello Cong and Jamal,

On Fri, 2018-10-19 at 13:40 -0700, Cong Wang wrote:
> On Thu, Oct 18, 2018 at 8:30 AM Davide Caratti  wrote:
> > The alternative is, we systematically forbid usage of 'goto chain' in
> > tcfg_paction, so that:
> > 
> > # tc f a dev v0 egress matchall action  random determ goto chain 
> > 4 5
> > 
> > is systematically rejected with -EINVAL. This comand never worked, so we
> > are not breaking anything in userspace.

> This is exactly why I asked you if we really need to support it. :)
> 
> If no one finds it useful, disallowing it is a good solution here, as
> we don't need
> to introduce any additional code to handle filter chains.

On Thu, 2018-10-18 at 08:52 -0400, Jamal Hadi Salim wrote:

> Rejection is a good solution[1].
> Would be helpful to set an ext_ack to something like
> "only one goto chain is supported currently"

OK to forbid 'goto chain' on fallback actions for gact and police: I just
sent out a small series for that, feedbacks are welcome.

@David: this patch is no more needed, it can be dropped from patchwork.

thanks!
regards,
-- 
davide

Re: [PATCH net v2] net/sched: act_gact: properly init 'goto chain'

2018-10-19 Thread Cong Wang 
On Thu, Oct 18, 2018 at 8:30 AM Davide Caratti  wrote:
> The alternative is, we systematically forbid usage of 'goto chain' in
> tcfg_paction, so that:
>
> # tc f a dev v0 egress matchall action  random determ goto chain 4 5
>
> is systematically rejected with -EINVAL. This comand never worked, so we
> are not breaking anything in userspace.

This is exactly why I asked you if we really need to support it. :)

If no one finds it useful, disallowing it is a good solution here, as
we don't need
to introduce any additional code to handle filter chains.

Re: [PATCH net v2] net/sched: act_gact: properly init 'goto chain'

2018-10-18 Thread Davide Caratti 
hello Jamal,

On Thu, 2018-10-18 at 08:52 -0400, Jamal Hadi Salim wrote:
> Rejection is a good solution[1].
> Would be helpful to set an ext_ack to something like
> "only one goto chain is supported currently"

ok, that's material for a v3, if you / Cong / others are ok with the other
hunks.

On Thu, 2018-10-18 at 08:52 -0400, Jamal Hadi Salim wrote:
> I didnt follow why you needed to introduce tcfg_caction...

it's a trick (maybe an abuse, up to you to decide): when the user does

 # tc f a dev v0 egress matchall action pass random determ goto chain 4 5

tcfg_caction contains 'pass', tcfg_paction and tcf_action both contain
'goto chain 4'. On the opposite, when the user does

 # tc f a dev v0 egress matchall action goto chain 4 random determ drop 5

tcfg_caction and tcf_action both contain 'goto chain 4', and tcf_paction
contains 'drop'. In this way, the 'goto chain' is always stored in
tcf_action, so that TC generic code can always initialize a->goto_chain.
(we need tcf_caction, becaue tcf_gact_dump() and helpers in tc_gact.h need
to read the control action on the left of "random")

The alternative is, we systematically forbid usage of 'goto chain' in
tcfg_paction, so that:

# tc f a dev v0 egress matchall action  random determ goto chain 4 5

is systematically rejected with -EINVAL. This comand never worked, so we
are not breaking anything in userspace.

thanks for reviewing!
-- 
davide

Re: [PATCH net v2] net/sched: act_gact: properly init 'goto chain'

2018-10-18 Thread Jamal Hadi Salim 

On 2018-10-18 8:05 a.m., Davide Caratti wrote:

the following script:

  # tc f a dev v0 egress chain 4 matchall action simple sdata "A triumph!"
  # tc f a dev v0 egress matchall action pass random determ goto chain 4 5

produces the following crash:

  BUG: unable to handle kernel NULL pointer dereference at 
  PGD 0 P4D 0
  Oops:  [#1] SMP PTI
  CPU: 9 PID: 0 Comm: swapper/9 Not tainted 4.19.0-rc6.chainfix + #472
  Hardware name: Supermicro SYS-6027R-72RF/X9DRH-7TF/7F/iTF/iF, BIOS 3.0  
07/26/2013
  RIP: 0010:tcf_action_exec+0xb8/0x100
  Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 
41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 
10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
  RSP: 0018:9af96f843bf8 EFLAGS: 00010246
  RAX: 202a RBX: 9af9679cf200 RCX: 005a
  RDX:  RSI: 0001 RDI: 9af585e006c0
  RBP: 9af96f843ca0 R08: 1600 R09: 
  R10:  R11:  R12: 9af968db4400
  R13: 9af968db4408 R14: 0001 R15: 9af585e006c0
  FS:  () GS:9af96f84() knlGS:
  CS:  0010 DS:  ES:  CR0: 80050033
  CR2:  CR3: 00025980a001 CR4: 001606e0
  Call Trace:
   
   tcf_classify+0x89/0x140
   __dev_queue_xmit+0x413/0x8a0
   ? ip6_finish_output2+0x336/0x520
   ip6_finish_output2+0x336/0x520
   ? ip6_output+0x68/0x110
   ip6_output+0x68/0x110
   ? ip6_fragment+0x9e0/0x9e0
   mld_sendpack+0x175/0x220
   ? mld_gq_timer_expire+0x40/0x40
   mld_dad_timer_expire+0x25/0x80
   call_timer_fn+0x2b/0x120
   run_timer_softirq+0x3e8/0x440
   ? tick_sched_timer+0x37/0x70
   ? __hrtimer_run_queues+0x118/0x290
   __do_softirq+0xe3/0x2bd
   irq_exit+0xe3/0xf0
   smp_apic_timer_interrupt+0x74/0x130
   apic_timer_interrupt+0xf/0x20
   
  RIP: 0010:cpuidle_enter_state+0xa5/0x320
  Code: 71 82 5f 7e e8 bc 25 ab ff 48 89 c3 0f 1f 44 00 00 31 ff e8 3d 36 ab ff 80 7c 
24 07 00 0f 85 28 02 00 00 fb 66 0f 1f 44 00 00 <4c> 29 f3 48 ba cf f7 53 e3 a5 
9b c4 20 48 89 d8 48 c1 fb 3f 48 f7
  RSP: 0018:afa1832cbe90 EFLAGS: 0246 ORIG_RAX: ff13
  RAX: 9af96f862600 RBX: 003ede349ac5 RCX: 001f
  RDX: 003ede349ac5 RSI: 313b14ef RDI: 
  RBP: cfa17fa40a00 R08: 9af96f85cdc0 R09: afc8
  R10: afa1832cbe70 R11: afc8 R12: 0004
  R13: 82578bd8 R14: 003ec085dc50 R15: 
   do_idle+0x200/0x280
   cpu_startup_entry+0x6f/0x80
   start_secondary+0x1a7/0x200
   secondary_startup_64+0xa4/0xb0
  Modules linked in: act_gact act_simple cls_matchall sch_ingress veth 
intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm 
irqbypass crct10dif_pclmul crc32_pclmul ipmi_ssif ghash_clmulni_intel pcbc 
aesni_intel ipmi_si iTCO_wdt crypto_simd iTCO_vendor_support cryptd mei_me 
ipmi_devintf glue_helper mei joydev ipmi_msghandler pcc_cpufreq sg lpc_ich 
pcspkr i2c_i801 ioatdma wmi ip_tables xfs libcrc32c mlx4_en sd_mod mgag200 
drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm isci drm 
libsas igb ahci libahci scsi_transport_sas mlx4_core be2net crc32c_intel dca 
libata i2c_algo_bit i2c_core megaraid_sas devlink dm_mirror dm_region_hash 
dm_log dm_mod
  CR2: 

when CONFIG_GACT_PROB is enabled, gact allows users to specify a fallback
control action, that is stored in the action private data. 'goto chain x'
never worked for that case, since goto_chain was never initialized. There
is only one goto_chain handle per action: ensure that gact never contains
more than one 'goto chain' in a rule. If the fallback control action is a
'goto chain', copy it to tcf_action to ensure that goto_chain is properly
initialized.

v2: - fix breakage of TDC tests when 'p_parm' is not specified
 - reject 'goto action' if it is specified twice in the same gact rule

Fixes: db50514f9a9c ("net: sched: add termination action to allow goto chain")
Signed-off-by: Davide Caratti 
---
  include/net/tc_act/tc_gact.h | 11 +--
  net/sched/act_gact.c | 19 ++-
  2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/include/net/tc_act/tc_gact.h b/include/net/tc_act/tc_gact.h
index ef8dd0db70ce..0cbeb77349bc 100644
--- a/include/net/tc_act/tc_gact.h
+++ b/include/net/tc_act/tc_gact.h
@@ -10,12 +10,19 @@ struct tcf_gact {
  #ifdef CONFIG_GACT_PROB
u16 tcfg_ptype;
u16 tcfg_pval;
+   int tcfg_caction;
int tcfg_paction;
atomic_tpackets;
  #endif
  };
  #define to_gact(a) ((struct tcf_gact *)a)
  
+#ifdef CONFIG_GACT_PROB

+#define GACT_PRIMARY_ACTION(g) ((g)->tcfg_caction)
+#else
+#define GACT_PRIMARY_ACTION(g) ((g)->tcf_action)
+#endif
+
  static inline

[PATCH net v2] net/sched: act_gact: properly init 'goto chain'

2018-10-18 Thread Davide Caratti 
the following script:

 # tc f a dev v0 egress chain 4 matchall action simple sdata "A triumph!"
 # tc f a dev v0 egress matchall action pass random determ goto chain 4 5

produces the following crash:

 BUG: unable to handle kernel NULL pointer dereference at 
 PGD 0 P4D 0
 Oops:  [#1] SMP PTI
 CPU: 9 PID: 0 Comm: swapper/9 Not tainted 4.19.0-rc6.chainfix + #472
 Hardware name: Supermicro SYS-6027R-72RF/X9DRH-7TF/7F/iTF/iF, BIOS 3.0  
07/26/2013
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 
5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 
83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:9af96f843bf8 EFLAGS: 00010246
 RAX: 202a RBX: 9af9679cf200 RCX: 005a
 RDX:  RSI: 0001 RDI: 9af585e006c0
 RBP: 9af96f843ca0 R08: 1600 R09: 
 R10:  R11:  R12: 9af968db4400
 R13: 9af968db4408 R14: 0001 R15: 9af585e006c0
 FS:  () GS:9af96f84() knlGS:
 CS:  0010 DS:  ES:  CR0: 80050033
 CR2:  CR3: 00025980a001 CR4: 001606e0
 Call Trace:
  
  tcf_classify+0x89/0x140
  __dev_queue_xmit+0x413/0x8a0
  ? ip6_finish_output2+0x336/0x520
  ip6_finish_output2+0x336/0x520
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? ip6_fragment+0x9e0/0x9e0
  mld_sendpack+0x175/0x220
  ? mld_gq_timer_expire+0x40/0x40
  mld_dad_timer_expire+0x25/0x80
  call_timer_fn+0x2b/0x120
  run_timer_softirq+0x3e8/0x440
  ? tick_sched_timer+0x37/0x70
  ? __hrtimer_run_queues+0x118/0x290
  __do_softirq+0xe3/0x2bd
  irq_exit+0xe3/0xf0
  smp_apic_timer_interrupt+0x74/0x130
  apic_timer_interrupt+0xf/0x20
  
 RIP: 0010:cpuidle_enter_state+0xa5/0x320
 Code: 71 82 5f 7e e8 bc 25 ab ff 48 89 c3 0f 1f 44 00 00 31 ff e8 3d 36 ab ff 
80 7c 24 07 00 0f 85 28 02 00 00 fb 66 0f 1f 44 00 00 <4c> 29 f3 48 ba cf f7 53 
e3 a5 9b c4 20 48 89 d8 48 c1 fb 3f 48 f7
 RSP: 0018:afa1832cbe90 EFLAGS: 0246 ORIG_RAX: ff13
 RAX: 9af96f862600 RBX: 003ede349ac5 RCX: 001f
 RDX: 003ede349ac5 RSI: 313b14ef RDI: 
 RBP: cfa17fa40a00 R08: 9af96f85cdc0 R09: afc8
 R10: afa1832cbe70 R11: afc8 R12: 0004
 R13: 82578bd8 R14: 003ec085dc50 R15: 
  do_idle+0x200/0x280
  cpu_startup_entry+0x6f/0x80
  start_secondary+0x1a7/0x200
  secondary_startup_64+0xa4/0xb0
 Modules linked in: act_gact act_simple cls_matchall sch_ingress veth 
intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm 
irqbypass crct10dif_pclmul crc32_pclmul ipmi_ssif ghash_clmulni_intel pcbc 
aesni_intel ipmi_si iTCO_wdt crypto_simd iTCO_vendor_support cryptd mei_me 
ipmi_devintf glue_helper mei joydev ipmi_msghandler pcc_cpufreq sg lpc_ich 
pcspkr i2c_i801 ioatdma wmi ip_tables xfs libcrc32c mlx4_en sd_mod mgag200 
drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm isci drm 
libsas igb ahci libahci scsi_transport_sas mlx4_core be2net crc32c_intel dca 
libata i2c_algo_bit i2c_core megaraid_sas devlink dm_mirror dm_region_hash 
dm_log dm_mod
 CR2: 

when CONFIG_GACT_PROB is enabled, gact allows users to specify a fallback
control action, that is stored in the action private data. 'goto chain x'
never worked for that case, since goto_chain was never initialized. There
is only one goto_chain handle per action: ensure that gact never contains
more than one 'goto chain' in a rule. If the fallback control action is a
'goto chain', copy it to tcf_action to ensure that goto_chain is properly
initialized.

v2: - fix breakage of TDC tests when 'p_parm' is not specified
- reject 'goto action' if it is specified twice in the same gact rule

Fixes: db50514f9a9c ("net: sched: add termination action to allow goto chain")
Signed-off-by: Davide Caratti 
---
 include/net/tc_act/tc_gact.h | 11 +--
 net/sched/act_gact.c | 19 ++-
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/include/net/tc_act/tc_gact.h b/include/net/tc_act/tc_gact.h
index ef8dd0db70ce..0cbeb77349bc 100644
--- a/include/net/tc_act/tc_gact.h
+++ b/include/net/tc_act/tc_gact.h
@@ -10,12 +10,19 @@ struct tcf_gact {
 #ifdef CONFIG_GACT_PROB
u16 tcfg_ptype;
u16 tcfg_pval;
+   int tcfg_caction;
int tcfg_paction;
atomic_tpackets;
 #endif
 };
 #define to_gact(a) ((struct tcf_gact *)a)
 
+#ifdef CONFIG_GACT_PROB
+#define GACT_PRIMARY_ACTION(g) ((g)->tcfg_caction)
+#else
+#define GACT_PRIMARY_ACTION(g) ((g)->tcf_action)
+#endif
+
 static inline bool __is_tcf_gact_act(const struct tc_action *a, int act,
 bool is_ext)
 {