Re: [PATCH] drivers: stm: correct the index in master array release
Chunyan Zhangwrites: > On Tue, Feb 9, 2016 at 6:12 PM, Alexander Shishkin > wrote: >> Chunyan Zhang writes: >> >>> It would be broken if stm_data->sw_start isn't zero, because that >>> stp_master_free() get the 'master' with __stm_master()/stm_master(), >>> in which the masterID is the second input parameter minus >>> stm_data->sw_start. So freeing STM masters has to start from >>> stm_data->sw_start. >> >> No, it won't. stm_master_free() handles nonexistent masters correctly. >> It does make sense to shrink the loop in stm_unregister_device() to >> avoid going through the [0..sw_start) range, since stm_master() returns >> NULL for those, but not for the reasons given in this patch description. > > Let's assume sw_start = 64, sw_end = 79, sw_nmasters should be 16, if > the loop goes through [0..16), the existed masters will not be freed. Ah yes, you're right, of course. I'll add this fix to the queue with a proper description. Thanks, -- Alex
Re: [PATCH] drivers: stm: correct the index in master array release
Chunyan Zhang writes: > On Tue, Feb 9, 2016 at 6:12 PM, Alexander Shishkin > wrote: >> Chunyan Zhang writes: >> >>> It would be broken if stm_data->sw_start isn't zero, because that >>> stp_master_free() get the 'master' with __stm_master()/stm_master(), >>> in which the masterID is the second input parameter minus >>> stm_data->sw_start. So freeing STM masters has to start from >>> stm_data->sw_start. >> >> No, it won't. stm_master_free() handles nonexistent masters correctly. >> It does make sense to shrink the loop in stm_unregister_device() to >> avoid going through the [0..sw_start) range, since stm_master() returns >> NULL for those, but not for the reasons given in this patch description. > > Let's assume sw_start = 64, sw_end = 79, sw_nmasters should be 16, if > the loop goes through [0..16), the existed masters will not be freed. Ah yes, you're right, of course. I'll add this fix to the queue with a proper description. Thanks, -- Alex
Re: [PATCH] drivers: stm: correct the index in master array release
On Tue, Feb 9, 2016 at 6:12 PM, Alexander Shishkin wrote: > Chunyan Zhang writes: > >> It would be broken if stm_data->sw_start isn't zero, because that >> stp_master_free() get the 'master' with __stm_master()/stm_master(), >> in which the masterID is the second input parameter minus >> stm_data->sw_start. So freeing STM masters has to start from >> stm_data->sw_start. > > No, it won't. stm_master_free() handles nonexistent masters correctly. > It does make sense to shrink the loop in stm_unregister_device() to > avoid going through the [0..sw_start) range, since stm_master() returns > NULL for those, but not for the reasons given in this patch description. Let's assume sw_start = 64, sw_end = 79, sw_nmasters should be 16, if the loop goes through [0..16), the existed masters will not be freed. That's what I wanted to address in this patch. I meant the number of loop in stm_unregister_device() is correct, but the start index isn't. Sorry for not describing clear enough in the patch logs. Thanks, Chunyan > > Regards, > -- > Alex
Re: [PATCH] drivers: stm: correct the index in master array release
On Tue, Feb 9, 2016 at 6:12 PM, Alexander Shishkinwrote: > Chunyan Zhang writes: > >> It would be broken if stm_data->sw_start isn't zero, because that >> stp_master_free() get the 'master' with __stm_master()/stm_master(), >> in which the masterID is the second input parameter minus >> stm_data->sw_start. So freeing STM masters has to start from >> stm_data->sw_start. > > No, it won't. stm_master_free() handles nonexistent masters correctly. > It does make sense to shrink the loop in stm_unregister_device() to > avoid going through the [0..sw_start) range, since stm_master() returns > NULL for those, but not for the reasons given in this patch description. Let's assume sw_start = 64, sw_end = 79, sw_nmasters should be 16, if the loop goes through [0..16), the existed masters will not be freed. That's what I wanted to address in this patch. I meant the number of loop in stm_unregister_device() is correct, but the start index isn't. Sorry for not describing clear enough in the patch logs. Thanks, Chunyan > > Regards, > -- > Alex
Re: [PATCH] drivers: stm: correct the index in master array release
Chunyan Zhang writes: > It would be broken if stm_data->sw_start isn't zero, because that > stp_master_free() get the 'master' with __stm_master()/stm_master(), > in which the masterID is the second input parameter minus > stm_data->sw_start. So freeing STM masters has to start from > stm_data->sw_start. No, it won't. stm_master_free() handles nonexistent masters correctly. It does make sense to shrink the loop in stm_unregister_device() to avoid going through the [0..sw_start) range, since stm_master() returns NULL for those, but not for the reasons given in this patch description. Regards, -- Alex
Re: [PATCH] drivers: stm: correct the index in master array release
Chunyan Zhangwrites: > It would be broken if stm_data->sw_start isn't zero, because that > stp_master_free() get the 'master' with __stm_master()/stm_master(), > in which the masterID is the second input parameter minus > stm_data->sw_start. So freeing STM masters has to start from > stm_data->sw_start. No, it won't. stm_master_free() handles nonexistent masters correctly. It does make sense to shrink the loop in stm_unregister_device() to avoid going through the [0..sw_start) range, since stm_master() returns NULL for those, but not for the reasons given in this patch description. Regards, -- Alex
[PATCH] drivers: stm: correct the index in master array release
It would be broken if stm_data->sw_start isn't zero, because that stp_master_free() get the 'master' with __stm_master()/stm_master(), in which the masterID is the second input parameter minus stm_data->sw_start. So freeing STM masters has to start from stm_data->sw_start. Signed-off-by: Chunyan Zhang --- drivers/hwtracing/stm/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index da53b5d..80e7b5e 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -718,7 +718,7 @@ void stm_unregister_device(struct stm_data *stm_data) stp_policy_unbind(stm->policy); mutex_unlock(>policy_mutex); - for (i = 0; i < stm->sw_nmasters; i++) + for (i = stm->data->sw_start; i <= stm->data->sw_end; i++) stp_master_free(stm, i); device_unregister(>dev); -- 1.9.1
[PATCH] drivers: stm: correct the index in master array release
It would be broken if stm_data->sw_start isn't zero, because that stp_master_free() get the 'master' with __stm_master()/stm_master(), in which the masterID is the second input parameter minus stm_data->sw_start. So freeing STM masters has to start from stm_data->sw_start. Signed-off-by: Chunyan Zhang--- drivers/hwtracing/stm/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index da53b5d..80e7b5e 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -718,7 +718,7 @@ void stm_unregister_device(struct stm_data *stm_data) stp_policy_unbind(stm->policy); mutex_unlock(>policy_mutex); - for (i = 0; i < stm->sw_nmasters; i++) + for (i = stm->data->sw_start; i <= stm->data->sw_end; i++) stp_master_free(stm, i); device_unregister(>dev); -- 1.9.1