Re: [PATCH 1/1] stp: rt: replace spin_lock with stp style lock and use STP_ALLOC_FLAGS

[yzhu1 <Yanjun dot Zhu at windriver dot com>]

Hi, Shukla

I am a beginner. To fix bug, I made this patch. Please comment it.

Thanks a lot.
Zhu Yanjun

On 10/22/2015 03:46 PM, Zhu Yanjun wrote:
> -rt mode spin lock lead to __might_sleep calltrace.
> Replacing spin lock with stp type raw lock and
> changing STP_ALLOC_SLEEP_FLAGS to STP_ALLOC_FLAGS solves the problem.
>
> Call Trace:
>   [<ffffffff818d83f1>] dump_stack+0x19/0x1b
>   [<ffffffff81070e3f>] __might_sleep+0xef/0x160
>   [<ffffffff818de710>] rt_spin_lock+0x20/0x50
>   [<ffffffff81178699>] d_path+0x79/0x1a0
>   [<ffffffffa0047be9>] __stp_get_mm_path.constprop.79+0x49/0x90 [stap_f5bb3e3c9b162aab5a51afc2375fe9cf_2073]
>   [<ffffffffa004d01b>] __stp_utrace_attach_match_tsk.isra.53+0x7b/0x1b0 [stap_f5bb3e3c9b162aab5a51afc2375fe9cf_2073]
>   [<ffffffffa004d18c>] __stp_utrace_task_finder_report_exec+0x3c/0x50 [stap_f5bb3e3c9b162aab5a51afc2375fe9cf_2073]
>   [<ffffffffa0047b59>] utrace_report_exec+0xb9/0x100 [stap_f5bb3e3c9b162aab5a51afc2375fe9cf_2073]
>   [<ffffffff811674b2>] search_binary_handler+0x332/0x380
>   [<ffffffff81168d0c>] do_execve_common.isra.24+0x55c/0x640
>   [<ffffffff81168e08>] do_execve+0x18/0x20
>   [<ffffffff81169082>] SyS_execve+0x32/0x50
>   [<ffffffff818e6979>] stub_execve+0x69/0xa0
>
> Signed-off-by: Zhu Yanjun <yanjun.zhu@windriver.com>
> ---
>   runtime/linux/alloc.c |   27 ++++++++++++++++-----------
>   1 file changed, 16 insertions(+), 11 deletions(-)
>
> diff --git a/runtime/linux/alloc.c b/runtime/linux/alloc.c
> index 7e7e5ce..914cf2b 100644
> --- a/runtime/linux/alloc.c
> +++ b/runtime/linux/alloc.c
> @@ -12,6 +12,7 @@
>   #define _STAPLINUX_ALLOC_C_
>   
>   #include <linux/percpu.h>
> +#include "stp_helper_lock.h"
>   
>   static int _stp_allocated_net_memory = 0;
>   /* Default, and should be "safe" from anywhere. */
> @@ -19,7 +20,11 @@ static int _stp_allocated_net_memory = 0;
>   			 & ~__GFP_WAIT)
>   /* May only be used in context that can sleep. __GFP_NORETRY is to
>      suppress the oom-killer from kicking in. */
> +#ifndef CONFIG_PREEMPT_RT_FULL
>   #define STP_ALLOC_SLEEP_FLAGS (GFP_KERNEL | __GFP_NORETRY)
> +#else
> +#define STP_ALLOC_SLEEP_FLAGS STP_ALLOC_FLAGS
> +#endif
>   
>   /* #define DEBUG_MEM */
>   /*
> @@ -40,7 +45,7 @@ static int _stp_allocated_net_memory = 0;
>   static int _stp_allocated_memory = 0;
>   
>   #ifdef DEBUG_MEM
> -static DEFINE_SPINLOCK(_stp_mem_lock);
> +static STP_DEFINE_SPINLOCK(_stp_mem_lock);
>   
>   #define MEM_MAGIC 0xc11cf77f
>   #define MEM_FENCE_SIZE 32
> @@ -108,9 +113,9 @@ static void *_stp_mem_debug_setup(void *addr, size_t size, enum _stp_memtype typ
>   	m->type = type;
>   	m->len = size;
>   	m->addr = addr;
> -	spin_lock(&_stp_mem_lock);
> +	stp_spin_lock(&_stp_mem_lock);
>   	list_add(p, &_stp_mem_list);
> -	spin_unlock(&_stp_mem_lock);
> +	stp_spin_unlock(&_stp_mem_lock);
>   	return addr;
>   }
>   
> @@ -122,9 +127,9 @@ static void _stp_mem_debug_percpu(struct _stp_mem_entry *m, void *addr, size_t s
>   	m->type = MEM_PERCPU;
>   	m->len = size;
>   	m->addr = addr;
> -	spin_lock(&_stp_mem_lock);
> +	stp_spin_lock(&_stp_mem_lock);
>   	list_add(p, &_stp_mem_list);
> -	spin_unlock(&_stp_mem_lock);	
> +	stp_spin_unlock(&_stp_mem_lock);	
>   }
>   
>   static void _stp_mem_debug_free(void *addr, enum _stp_memtype type)
> @@ -133,7 +138,7 @@ static void _stp_mem_debug_free(void *addr, enum _stp_memtype type)
>   	struct list_head *p, *tmp;
>   	struct _stp_mem_entry *m = NULL;
>   
> -	spin_lock(&_stp_mem_lock);
> +	stp_spin_lock(&_stp_mem_lock);
>   	list_for_each_safe(p, tmp, &_stp_mem_list) {
>   		m = list_entry(p, struct _stp_mem_entry, list);
>   		if (m->addr == addr) {
> @@ -142,7 +147,7 @@ static void _stp_mem_debug_free(void *addr, enum _stp_memtype type)
>   			break;
>   		}
>   	}
> -	spin_unlock(&_stp_mem_lock);
> +	stp_spin_unlock(&_stp_mem_lock);
>   	if (!found) {
>   		printk("SYSTEMTAP ERROR: Free of unallocated memory %p type=%s\n",
>   		       addr, _stp_malloc_types[type].free);
> @@ -184,7 +189,7 @@ static void _stp_mem_debug_validate(void *addr)
>   	struct list_head *p, *tmp;
>   	struct _stp_mem_entry *m = NULL;
>   
> -	spin_lock(&_stp_mem_lock);
> +	stp_spin_lock(&_stp_mem_lock);
>   	list_for_each_safe(p, tmp, &_stp_mem_list) {
>   		m = list_entry(p, struct _stp_mem_entry, list);
>   		if (m->addr == addr) {
> @@ -192,7 +197,7 @@ static void _stp_mem_debug_validate(void *addr)
>   			break;
>   		}
>   	}
> -	spin_unlock(&_stp_mem_lock);
> +	stp_spin_unlock(&_stp_mem_lock);
>   	if (!found) {
>   		printk("SYSTEMTAP ERROR: Couldn't validate memory %p\n",
>   		       addr);
> @@ -551,7 +556,7 @@ static void _stp_mem_debug_done(void)
>   	struct list_head *p, *tmp;
>   	struct _stp_mem_entry *m;
>   
> -	spin_lock(&_stp_mem_lock);
> +	stp_spin_lock(&_stp_mem_lock);
>   	list_for_each_safe(p, tmp, &_stp_mem_list) {
>   		m = list_entry(p, struct _stp_mem_entry, list);
>   		list_del(p);
> @@ -583,7 +588,7 @@ static void _stp_mem_debug_done(void)
>   		}
>   	}
>   done:
> -	spin_unlock(&_stp_mem_lock);
> +	stp_spin_unlock(&_stp_mem_lock);
>   
>   	return;
>