From 32a9ff9cc55b42543a84bca90b070df92af72671 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 19 Jun 2009 10:41:19 +0200 Subject: lib/checksum.c: fix endianess bug The new generic checksum code has a small dependency on endianess and worked only on big-endian systems. I could not find a nice efficient way to express this, so I added an #ifdef. Using 'result += le16_to_cpu(*buff);' would have worked as well, but would be slightly less efficient on big-endian systems and IMHO would not be clearer. Also fix a bug that prevents this from working on 64-bit machines. If you have a 64-bit CPU and want to use the generic checksum code, you should probably do some more optimizations anyway, but at least the code should not break. Reported-by: Mike Frysinger Signed-off-by: Arnd Bergmann --- lib/checksum.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/checksum.c b/lib/checksum.c index 12e5a1c91cda..b2e2fd468461 100644 --- a/lib/checksum.c +++ b/lib/checksum.c @@ -55,7 +55,11 @@ static unsigned int do_csum(const unsigned char *buff, int len) goto out; odd = 1 & (unsigned long) buff; if (odd) { +#ifdef __LITTLE_ENDIAN result = *buff; +#else + result += (*buff << 8); +#endif len--; buff++; } @@ -71,7 +75,7 @@ static unsigned int do_csum(const unsigned char *buff, int len) if (count) { unsigned long carry = 0; do { - unsigned long w = *(unsigned long *) buff; + unsigned long w = *(unsigned int *) buff; count--; buff += 4; result += carry; @@ -87,7 +91,11 @@ static unsigned int do_csum(const unsigned char *buff, int len) } } if (len & 1) +#ifdef __LITTLE_ENDIAN + result += *buff; +#else result += (*buff << 8); +#endif result = from32to16(result); if (odd) result = ((result >> 8) & 0xff) | ((result & 0xff) << 8); -- cgit v1.2.3 From bf96d1e3e7a35a17cea255048ffb3243bd9c8123 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Tue, 23 Jun 2009 14:40:27 +0100 Subject: kmemleak: Do not force the slab debugging Kconfig options Selecting DEBUG_SLAB or SLUB_DEBUG by the KMEMLEAK menu entry may cause issues with other dependencies (KMEMCHECK). These configuration options aren't strictly needed by kmemleak but they may increase the chances of finding leaks. This patch also updates the KMEMLEAK config entry help text. Signed-off-by: Catalin Marinas Acked-by: Pekka Enberg --- lib/Kconfig.debug | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 23067ab1a73c..4c32b1a1a06e 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -340,8 +340,6 @@ config DEBUG_KMEMLEAK bool "Kernel memory leak detector" depends on DEBUG_KERNEL && EXPERIMENTAL && (X86 || ARM) && \ !MEMORY_HOTPLUG - select DEBUG_SLAB if SLAB - select SLUB_DEBUG if SLUB select DEBUG_FS if SYSFS select STACKTRACE if STACKTRACE_SUPPORT select KALLSYMS @@ -355,6 +353,9 @@ config DEBUG_KMEMLEAK allocations. See Documentation/kmemleak.txt for more details. + Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances + of finding leaks due to the slab objects poisoning. + In order to access the kmemleak file, debugfs needs to be mounted (usually at /sys/kernel/debug). -- cgit v1.2.3 From a9d9058abab4ac17b79d500506e6c74bd16cecdc Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Thu, 25 Jun 2009 10:16:11 +0100 Subject: kmemleak: Allow the early log buffer to be configurable. (feature suggested by Sergey Senozhatsky) Kmemleak needs to track all the memory allocations but some of these happen before kmemleak is initialised. These are stored in an internal buffer which may be exceeded in some kernel configurations. This patch adds a configuration option with a default value of 400 and also removes the stack dump when the early log buffer is exceeded. Signed-off-by: Catalin Marinas Acked-by: Sergey Senozhatsky --- Documentation/kmemleak.txt | 4 ++++ lib/Kconfig.debug | 12 ++++++++++++ mm/kmemleak.c | 5 +++-- 3 files changed, 19 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/Documentation/kmemleak.txt b/Documentation/kmemleak.txt index 0112da3b9ab8..f655308064d7 100644 --- a/Documentation/kmemleak.txt +++ b/Documentation/kmemleak.txt @@ -41,6 +41,10 @@ Memory scanning parameters can be modified at run-time by writing to the Kmemleak can also be disabled at boot-time by passing "kmemleak=off" on the kernel command line. +Memory may be allocated or freed before kmemleak is initialised and +these actions are stored in an early log buffer. The size of this buffer +is configured via the CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE option. + Basic Algorithm --------------- diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 4c32b1a1a06e..12327b2bb785 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -359,6 +359,18 @@ config DEBUG_KMEMLEAK In order to access the kmemleak file, debugfs needs to be mounted (usually at /sys/kernel/debug). +config DEBUG_KMEMLEAK_EARLY_LOG_SIZE + int "Maximum kmemleak early log entries" + depends on DEBUG_KMEMLEAK + range 200 2000 + default 400 + help + Kmemleak must track all the memory allocations to avoid + reporting false positives. Since memory may be allocated or + freed before kmemleak is initialised, an early log buffer is + used to store these actions. If kmemleak reports "early log + buffer exceeded", please increase this value. + config DEBUG_KMEMLEAK_TEST tristate "Simple test for the kernel memory leak detector" depends on DEBUG_KMEMLEAK diff --git a/mm/kmemleak.c b/mm/kmemleak.c index c96f2c8700aa..17096d1b59b2 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -235,7 +235,7 @@ struct early_log { }; /* early logging buffer and current position */ -static struct early_log early_log[200]; +static struct early_log early_log[CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE]; static int crt_early_log; static void kmemleak_disable(void); @@ -696,7 +696,8 @@ static void log_early(int op_type, const void *ptr, size_t size, struct early_log *log; if (crt_early_log >= ARRAY_SIZE(early_log)) { - kmemleak_stop("Early log buffer exceeded\n"); + pr_warning("Early log buffer exceeded\n"); + kmemleak_disable(); return; } -- cgit v1.2.3