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authorHelge Deller <deller@gmx.de>2013-05-07 19:28:52 +0000
committerHelge Deller <deller@gmx.de>2013-05-07 21:34:07 +0200
commit9372450cc22d185f708e5cc3557cf991be4b7dc5 (patch)
treef537999c1134549b14fce04a020e6e4d23d03d4c /arch/parisc/include
parentc207a76bf155cb5cf24cf849c08f6555e9180594 (diff)
parisc: add kernel stack overflow check
Add the CONFIG_DEBUG_STACKOVERFLOW config option to enable checks to detect kernel stack overflows. Stack overflows can not be detected reliable since we do not want to introduce too much overhead. Instead, during irq processing in do_cpu_irq_mask() we check kernel stack usage of the interrupted kernel process. Kernel threads can be easily detected by checking the value of space register 7 (sr7) which is zero when running inside the kernel. Since THREAD_SIZE is 16k and PAGE_SIZE is 4k, reduce the alignment of the init thread to the lower value (PAGE_SIZE) in the kernel vmlinux.ld.S linker script. Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'arch/parisc/include')
-rw-r--r--arch/parisc/include/asm/thread_info.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/parisc/include/asm/thread_info.h b/arch/parisc/include/asm/thread_info.h
index 6182832e5b6c..540c88fa8f86 100644
--- a/arch/parisc/include/asm/thread_info.h
+++ b/arch/parisc/include/asm/thread_info.h
@@ -40,7 +40,7 @@ struct thread_info {
/* thread information allocation */
-#define THREAD_SIZE_ORDER 2
+#define THREAD_SIZE_ORDER 2 /* PA-RISC requires at least 16k stack */
/* Be sure to hunt all references to this down when you change the size of
* the kernel stack */
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)