lkml.org 
[lkml]   [2021]   [Jan]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] kdb: Make memory allocations more robust
Date
Currently kdb uses in_interrupt() to determine whether it's library
code has been called from the kgdb trap handler or from a saner calling
context such as driver init. This approach is broken because
in_interrupt() alone isn't able to determine kgdb trap handler entry via
normal task context such as [1].

We can improve this by adding check for in_dbg_master() instead which
explicitly determines if we are running in debugger context.

[1] $ echo g > /proc/sysrq-trigger

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
---

Changes in v2:
- Get rid of redundant in_atomic() check.

kernel/debug/kdb/kdb_private.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index 7a4a181..344eb0d 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -231,7 +231,7 @@ extern struct task_struct *kdb_curr_task(int);

#define kdb_task_has_cpu(p) (task_curr(p))

-#define GFP_KDB (in_interrupt() ? GFP_ATOMIC : GFP_KERNEL)
+#define GFP_KDB (in_dbg_master() ? GFP_ATOMIC : GFP_KERNEL)

extern void *debug_kmalloc(size_t size, gfp_t flags);
extern void debug_kfree(void *);
--
2.7.4
\
 
 \ /
  Last update: 2021-01-22 11:36    [W:0.034 / U:1.608 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site