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s390/cio: fix accidental interrupt enabling during resume 

Since commit 9f3d6d7 chsc_get_channel_measurement_chars is called with
interrupts disabled during resume from hibernate. Since this function
used spin_unlock_irq, interrupts have been enabled accidentally. Fix
this by using the irqsave variant.

Since we can't guarantee the IRQ-enablement state for all (future/
external) callers, change the locking in related functions to prevent
similar bugs in the future.

Fixes: 9f3d6d7 ("s390/cio: update measurement characteristics")
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Sebastian Ott 2016-09-28 13:36:19 +02:00 committed by Martin Schwidefsky
parent 871f8bf0c4
commit d53c51f261
1 changed files with 12 additions and 8 deletions
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20
drivers/s390/cio/chsc.c
View File

@ -95,12 +95,13 @@ struct chsc_ssd_area {
int chsc_get_ssd_info(struct subchannel_id schid, struct chsc_ssd_info *ssd)
{
struct chsc_ssd_area *ssd_area;
unsigned long flags;
int ccode;
int ret;
int i;
int mask;
spin_lock_irq(&chsc_page_lock);
spin_lock_irqsave(&chsc_page_lock, flags);
memset(chsc_page, 0, PAGE_SIZE);
ssd_area = chsc_page;
ssd_area->request.length = 0x0010;
@ -144,7 +145,7 @@ int chsc_get_ssd_info(struct subchannel_id schid, struct chsc_ssd_info *ssd)
ssd->fla[i] = ssd_area->fla[i];
}
out:
spin_unlock_irq(&chsc_page_lock);
spin_unlock_irqrestore(&chsc_page_lock, flags);
return ret;
}
@ -832,9 +833,10 @@ int __chsc_do_secm(struct channel_subsystem *css, int enable)
u32 fmt : 4;
u32 : 16;
} __attribute__ ((packed)) *secm_area;
unsigned long flags;
int ret, ccode;
spin_lock_irq(&chsc_page_lock);
spin_lock_irqsave(&chsc_page_lock, flags);
memset(chsc_page, 0, PAGE_SIZE);
secm_area = chsc_page;
secm_area->request.length = 0x0050;
@ -864,7 +866,7 @@ int __chsc_do_secm(struct channel_subsystem *css, int enable)
CIO_CRW_EVENT(2, "chsc: secm failed (rc=%04x)\n",
secm_area->response.code);
out:
spin_unlock_irq(&chsc_page_lock);
spin_unlock_irqrestore(&chsc_page_lock, flags);
return ret;
}
@ -992,6 +994,7 @@ chsc_initialize_cmg_chars(struct channel_path *chp, u8 cmcv,
int chsc_get_channel_measurement_chars(struct channel_path *chp)
{
unsigned long flags;
int ccode, ret;
struct {
@ -1021,7 +1024,7 @@ int chsc_get_channel_measurement_chars(struct channel_path *chp)
if (!css_chsc_characteristics.scmc || !css_chsc_characteristics.secm)
return -EINVAL;
spin_lock_irq(&chsc_page_lock);
spin_lock_irqsave(&chsc_page_lock, flags);
memset(chsc_page, 0, PAGE_SIZE);
scmc_area = chsc_page;
scmc_area->request.length = 0x0010;
@ -1053,7 +1056,7 @@ int chsc_get_channel_measurement_chars(struct channel_path *chp)
chsc_initialize_cmg_chars(chp, scmc_area->cmcv,
(struct cmg_chars *) &scmc_area->data);
out:
spin_unlock_irq(&chsc_page_lock);
spin_unlock_irqrestore(&chsc_page_lock, flags);
return ret;
}
@ -1134,6 +1137,7 @@ struct css_chsc_char css_chsc_characteristics;
int __init
chsc_determine_css_characteristics(void)
{
unsigned long flags;
int result;
struct {
struct chsc_header request;
@ -1146,7 +1150,7 @@ chsc_determine_css_characteristics(void)
u32 chsc_char[508];
} __attribute__ ((packed)) *scsc_area;
spin_lock_irq(&chsc_page_lock);
spin_lock_irqsave(&chsc_page_lock, flags);
memset(chsc_page, 0, PAGE_SIZE);
scsc_area = chsc_page;
scsc_area->request.length = 0x0010;
@ -1168,7 +1172,7 @@ chsc_determine_css_characteristics(void)
CIO_CRW_EVENT(2, "chsc: scsc failed (rc=%04x)\n",
scsc_area->response.code);
exit:
spin_unlock_irq(&chsc_page_lock);
spin_unlock_irqrestore(&chsc_page_lock, flags);
return result;
}