| Message ID | CA+v9cxYuFArVUh9gc-be-Lmy4TOTxp72VaCC4QeCEE3p1j2Ykg@mail.gmail.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
Le samedi 24 septembre 2011 à 23:57 +0800, Huajun Li a écrit : > While preparing flow caches, once fail may cause potential memory leak , fix it. > > Signed-off-by: Huajun Li <huajun.li.lee@gmail.com> > --- > net/core/flow.c | 19 ++++++++++++++++++- > 1 files changed, 18 insertions(+), 1 deletions(-) > > diff --git a/net/core/flow.c b/net/core/flow.c > index ba3e617..2dcaa03 100644 > --- a/net/core/flow.c > +++ b/net/core/flow.c > @@ -420,7 +420,7 @@ static int __init flow_cache_init(struct flow_cache *fc) > > for_each_online_cpu(i) { > if (flow_cache_cpu_prepare(fc, i)) > - return -ENOMEM; > + goto err; > } > fc->hotcpu_notifier = (struct notifier_block){ > .notifier_call = flow_cache_cpu, > @@ -433,6 +433,23 @@ static int __init flow_cache_init(struct flow_cache *fc) > add_timer(&fc->rnd_timer); > > return 0; > +err: > + if (fc->percpu) { > + free_percpu(fc->percpu); > + fc->percpu = NULL; > + } > + > + /* > + * Check each possible CPUs rather than online ones because they may be > + * offline before the notifier is registered. > + */ Please remove this comment. > + for_each_possible_cpu(i) { > + struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, i); > + kfree(fcp->hash_table); > + fcp->hash_table = NULL; > + } You access fc->percpu after freeing it... > + > + return -ENOMEM; > } > > static int __init flow_cache_init_global(void) Previous to 2.6.37 (commit 83b6b1f5d134), a memory allocation at this stage was panicing the box, so no worry about mem leak :) Now I wonder if a proper patch would not print a nice message in flow_cache_init_global() if flow_cache_init() returns an error, instead of silently panicing or something worse... Before submitting a new patch, could you test this case (injecting a memalloc error in flow_cache_cpu_prepare() for example. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Eric, thanks for your comment. 2011/9/26 Eric Dumazet <eric.dumazet@gmail.com>: > Le samedi 24 septembre 2011 à 23:57 +0800, Huajun Li a écrit : >> While preparing flow caches, once fail may cause potential memory leak , fix it. >> >> Signed-off-by: Huajun Li <huajun.li.lee@gmail.com> >> --- >> net/core/flow.c | 19 ++++++++++++++++++- >> 1 files changed, 18 insertions(+), 1 deletions(-) >> >> diff --git a/net/core/flow.c b/net/core/flow.c >> index ba3e617..2dcaa03 100644 >> --- a/net/core/flow.c >> +++ b/net/core/flow.c >> @@ -420,7 +420,7 @@ static int __init flow_cache_init(struct flow_cache *fc) >> >> for_each_online_cpu(i) { >> if (flow_cache_cpu_prepare(fc, i)) >> - return -ENOMEM; >> + goto err; >> } >> fc->hotcpu_notifier = (struct notifier_block){ >> .notifier_call = flow_cache_cpu, >> @@ -433,6 +433,23 @@ static int __init flow_cache_init(struct flow_cache *fc) >> add_timer(&fc->rnd_timer); >> >> return 0; >> +err: >> + if (fc->percpu) { >> + free_percpu(fc->percpu); >> + fc->percpu = NULL; >> + } >> + >> + /* >> + * Check each possible CPUs rather than online ones because they may be >> + * offline before the notifier is registered. >> + */ > > Please remove this comment. > Sure. > >> + for_each_possible_cpu(i) { >> + struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, i); >> + kfree(fcp->hash_table); >> + fcp->hash_table = NULL; >> + } > > You access fc->percpu after freeing it... > Yes, need change the order to free memory. >> + >> + return -ENOMEM; >> } >> >> static int __init flow_cache_init_global(void) > > Previous to 2.6.37 (commit 83b6b1f5d134), a memory allocation at this > stage was panicing the box, so no worry about mem leak :) > > Now I wonder if a proper patch would not print a nice message in > flow_cache_init_global() if flow_cache_init() returns an error, instead > of silently panicing or something worse... > There prints err msg in flow_cache_cpu_prepare(L369) if fails to allocate memory. Do you mean it should give more detail error info, right ? > Before submitting a new patch, could you test this case (injecting a > memalloc error in flow_cache_cpu_prepare() for example. > Will test it further if new patch comes. ;) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2011/9/26 Eric Dumazet <eric.dumazet@gmail.com>: > Le samedi 24 septembre 2011 à 23:57 +0800, Huajun Li a écrit : >> While preparing flow caches, once fail may cause potential memory leak , fix it. >> >> Signed-off-by: Huajun Li <huajun.li.lee@gmail.com> >> --- >> net/core/flow.c | 19 ++++++++++++++++++- >> 1 files changed, 18 insertions(+), 1 deletions(-) >> >> diff --git a/net/core/flow.c b/net/core/flow.c >> index ba3e617..2dcaa03 100644 >> --- a/net/core/flow.c >> +++ b/net/core/flow.c >> @@ -420,7 +420,7 @@ static int __init flow_cache_init(struct flow_cache *fc) >> >> for_each_online_cpu(i) { >> if (flow_cache_cpu_prepare(fc, i)) >> - return -ENOMEM; >> + goto err; >> } >> fc->hotcpu_notifier = (struct notifier_block){ >> .notifier_call = flow_cache_cpu, >> @@ -433,6 +433,23 @@ static int __init flow_cache_init(struct flow_cache *fc) >> add_timer(&fc->rnd_timer); >> >> return 0; >> +err: >> + if (fc->percpu) { >> + free_percpu(fc->percpu); >> + fc->percpu = NULL; >> + } >> + >> + /* >> + * Check each possible CPUs rather than online ones because they may be >> + * offline before the notifier is registered. >> + */ > > Please remove this comment. > > >> + for_each_possible_cpu(i) { >> + struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, i); >> + kfree(fcp->hash_table); >> + fcp->hash_table = NULL; >> + } > > You access fc->percpu after freeing it... > >> + >> + return -ENOMEM; >> } >> >> static int __init flow_cache_init_global(void) > > Previous to 2.6.37 (commit 83b6b1f5d134), a memory allocation at this > stage was panicing the box, so no worry about mem leak :) > To emulate memory allocation fail case, I added code to return '-ENOMEM' from flow_cache_cpu_prepare(...) even if it could allocate memory correctly, but did not find panic on my box, maybe the latest code changed greatly than 2.6.37. :) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Le mardi 27 septembre 2011 à 17:58 +0800, Huajun Li a écrit : > To emulate memory allocation fail case, I added code to return > '-ENOMEM' from flow_cache_cpu_prepare(...) even if it could allocate > memory correctly, but did not find panic on my box, maybe the latest > code changed greatly than 2.6.37. :) To panic the box, you need to leave a NULL pointer somewhere and dereference it later, when code assumes it cant be NULL ;) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/core/flow.c b/net/core/flow.c index ba3e617..2dcaa03 100644 --- a/net/core/flow.c +++ b/net/core/flow.c @@ -420,7 +420,7 @@ static int __init flow_cache_init(struct flow_cache *fc) for_each_online_cpu(i) { if (flow_cache_cpu_prepare(fc, i)) - return -ENOMEM; + goto err; } fc->hotcpu_notifier = (struct notifier_block){ .notifier_call = flow_cache_cpu, @@ -433,6 +433,23 @@ static int __init flow_cache_init(struct flow_cache *fc) add_timer(&fc->rnd_timer); return 0; +err: + if (fc->percpu) { + free_percpu(fc->percpu); + fc->percpu = NULL; + } + + /* + * Check each possible CPUs rather than online ones because they may be + * offline before the notifier is registered. + */ + for_each_possible_cpu(i) { + struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, i); + kfree(fcp->hash_table); + fcp->hash_table = NULL; + } + + return -ENOMEM; } static int __init flow_cache_init_global(void)
While preparing flow caches, once fail may cause potential memory leak , fix it. Signed-off-by: Huajun Li <huajun.li.lee@gmail.com> --- net/core/flow.c | 19 ++++++++++++++++++- 1 files changed, 18 insertions(+), 1 deletions(-)