From 329409aeda064c4aff00c51f837fcd3bbdaeeba6 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Fri, 8 Dec 2006 02:39:48 -0800 Subject: [PATCH] fault injection: stacktrace filtering This patch provides stacktrace filtering feature. The stacktrace filter allows failing only for the caller you are interested in. For example someone may want to inject kmalloc() failures into only e100 module. they want to inject not only direct kmalloc() call, but also indirect allocation, too. - e100_poll --> netif_receive_skb --> packet_rcv_spkt --> skb_clone --> kmem_cache_alloc This patch enables to detect function calls like this by stacktrace and inject failures. The script Documentaion/fault-injection/failmodule.sh helps it. The range of text section of loaded e100 is expected to be [/sys/module/e100/sections/.text, /sys/module/e100/sections/.exit.text) So failmodule.sh stores these values into /debug/failslab/address-start and /debug/failslab/address-end. The maximum stacktrace depth is specified by /debug/failslab/stacktrace-depth. Please see the example that demonstrates how to inject slab allocation failures only for a specific module in Documentation/fault-injection/fault-injection.txt [dwm@meer.net: reject failure if any caller lies within specified range] Signed-off-by: Akinobu Mita Signed-off-by: Don Mullis Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/fault-injection/fault-injection.txt | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'Documentation/fault-injection') diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt index cf075c20eda..6d6e5ac5ea9 100644 --- a/Documentation/fault-injection/fault-injection.txt +++ b/Documentation/fault-injection/fault-injection.txt @@ -73,13 +73,17 @@ configuration of fault-injection capabilities. Any positive value limits failures to only processes indicated by /proc//make-it-fail==1. -- /debug/*/address-start: -- /debug/*/address-end: +- /debug/*/require-start: +- /debug/*/require-end: +- /debug/*/reject-start: +- /debug/*/reject-end: specifies the range of virtual addresses tested during stacktrace walking. Failure is injected only if some caller - in the walked stacktrace lies within this range. - Default is [0,ULONG_MAX) (whole of virtual address space). + in the walked stacktrace lies within the required range, and + none lies within the rejected range. + Default required range is [0,ULONG_MAX) (whole of virtual address space). + Default rejected range is [0,0). - /debug/*/stacktrace-depth: -- cgit v1.2.3