diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 66 | ||||
| -rw-r--r-- | lib/cpumask.c | 9 | ||||
| -rw-r--r-- | lib/mpi/longlong.h | 4 | ||||
| -rw-r--r-- | lib/rhashtable.c | 1 | ||||
| -rw-r--r-- | lib/strnlen_user.c | 12 | ||||
| -rw-r--r-- | lib/swiotlb.c | 5 |
6 files changed, 84 insertions, 13 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index ba2b0c87e65b..b908048f8d6a 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1233,6 +1233,7 @@ config RCU_TORTURE_TEST depends on DEBUG_KERNEL select TORTURE_TEST select SRCU + select TASKS_RCU default n help This option provides a kernel module that runs torture tests @@ -1261,12 +1262,38 @@ config RCU_TORTURE_TEST_RUNNABLE Say N here if you want the RCU torture tests to start only after being manually enabled via /proc. +config RCU_TORTURE_TEST_SLOW_PREINIT + bool "Slow down RCU grace-period pre-initialization to expose races" + depends on RCU_TORTURE_TEST + help + This option delays grace-period pre-initialization (the + propagation of CPU-hotplug changes up the rcu_node combining + tree) for a few jiffies between initializing each pair of + consecutive rcu_node structures. This helps to expose races + involving grace-period pre-initialization, in other words, it + makes your kernel less stable. It can also greatly increase + grace-period latency, especially on systems with large numbers + of CPUs. This is useful when torture-testing RCU, but in + almost no other circumstance. + + Say Y here if you want your system to crash and hang more often. + Say N if you want a sane system. + +config RCU_TORTURE_TEST_SLOW_PREINIT_DELAY + int "How much to slow down RCU grace-period pre-initialization" + range 0 5 + default 3 + depends on RCU_TORTURE_TEST_SLOW_PREINIT + help + This option specifies the number of jiffies to wait between + each rcu_node structure pre-initialization step. + config RCU_TORTURE_TEST_SLOW_INIT bool "Slow down RCU grace-period initialization to expose races" depends on RCU_TORTURE_TEST help - This option makes grace-period initialization block for a - few jiffies between initializing each pair of consecutive + This option delays grace-period initialization for a few + jiffies between initializing each pair of consecutive rcu_node structures. This helps to expose races involving grace-period initialization, in other words, it makes your kernel less stable. It can also greatly increase grace-period @@ -1286,6 +1313,30 @@ config RCU_TORTURE_TEST_SLOW_INIT_DELAY This option specifies the number of jiffies to wait between each rcu_node structure initialization. +config RCU_TORTURE_TEST_SLOW_CLEANUP + bool "Slow down RCU grace-period cleanup to expose races" + depends on RCU_TORTURE_TEST + help + This option delays grace-period cleanup for a few jiffies + between cleaning up each pair of consecutive rcu_node + structures. This helps to expose races involving grace-period + cleanup, in other words, it makes your kernel less stable. + It can also greatly increase grace-period latency, especially + on systems with large numbers of CPUs. This is useful when + torture-testing RCU, but in almost no other circumstance. + + Say Y here if you want your system to crash and hang more often. + Say N if you want a sane system. + +config RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY + int "How much to slow down RCU grace-period cleanup" + range 0 5 + default 3 + depends on RCU_TORTURE_TEST_SLOW_CLEANUP + help + This option specifies the number of jiffies to wait between + each rcu_node structure cleanup operation. + config RCU_CPU_STALL_TIMEOUT int "RCU CPU stall timeout in seconds" depends on RCU_STALL_COMMON @@ -1322,6 +1373,17 @@ config RCU_TRACE Say Y here if you want to enable RCU tracing Say N if you are unsure. +config RCU_EQS_DEBUG + bool "Use this when adding any sort of NO_HZ support to your arch" + depends on DEBUG_KERNEL + help + This option provides consistency checks in RCU's handling of + NO_HZ. These checks have proven quite helpful in detecting + bugs in arch-specific NO_HZ code. + + Say N here if you need ultimate kernel/user switch latencies + Say Y if you are unsure + endmenu # "RCU Debugging" config DEBUG_BLOCK_EXT_DEVT diff --git a/lib/cpumask.c b/lib/cpumask.c index 5f627084f2e9..5a70f6196f57 100644 --- a/lib/cpumask.c +++ b/lib/cpumask.c @@ -16,11 +16,10 @@ int cpumask_next_and(int n, const struct cpumask *src1p, const struct cpumask *src2p) { - struct cpumask tmp; - - if (cpumask_and(&tmp, src1p, src2p)) - return cpumask_next(n, &tmp); - return nr_cpu_ids; + while ((n = cpumask_next(n, src1p)) < nr_cpu_ids) + if (cpumask_test_cpu(n, src2p)) + break; + return n; } EXPORT_SYMBOL(cpumask_next_and); diff --git a/lib/mpi/longlong.h b/lib/mpi/longlong.h index aac511417ad1..a89d041592c8 100644 --- a/lib/mpi/longlong.h +++ b/lib/mpi/longlong.h @@ -639,7 +639,7 @@ do { \ ************** MIPS ***************** ***************************************/ #if defined(__mips__) && W_TYPE_SIZE == 32 -#if __GNUC__ >= 4 && __GNUC_MINOR__ >= 4 +#if (__GNUC__ >= 5) || (__GNUC__ >= 4 && __GNUC_MINOR__ >= 4) #define umul_ppmm(w1, w0, u, v) \ do { \ UDItype __ll = (UDItype)(u) * (v); \ @@ -671,7 +671,7 @@ do { \ ************** MIPS/64 ************** ***************************************/ #if (defined(__mips) && __mips >= 3) && W_TYPE_SIZE == 64 -#if __GNUC__ >= 4 && __GNUC_MINOR__ >= 4 +#if (__GNUC__ >= 5) || (__GNUC__ >= 4 && __GNUC_MINOR__ >= 4) #define umul_ppmm(w1, w0, u, v) \ do { \ typedef unsigned int __ll_UTItype __attribute__((mode(TI))); \ diff --git a/lib/rhashtable.c b/lib/rhashtable.c index 4396434e4715..8609378e6505 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -26,6 +26,7 @@ #include <linux/random.h> #include <linux/rhashtable.h> #include <linux/err.h> +#include <linux/export.h> #define HASH_DEFAULT_SIZE 64UL #define HASH_MIN_SIZE 4U diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c index 36c15a2889e4..3a5f2b366d84 100644 --- a/lib/strnlen_user.c +++ b/lib/strnlen_user.c @@ -57,7 +57,8 @@ static inline long do_strnlen_user(const char __user *src, unsigned long count, return res + find_zero(data) + 1 - align; } res += sizeof(unsigned long); - if (unlikely(max < sizeof(unsigned long))) + /* We already handled 'unsigned long' bytes. Did we do it all ? */ + if (unlikely(max <= sizeof(unsigned long))) break; max -= sizeof(unsigned long); if (unlikely(__get_user(c,(unsigned long __user *)(src+res)))) @@ -90,8 +91,15 @@ static inline long do_strnlen_user(const char __user *src, unsigned long count, * Get the size of a NUL-terminated string in user space. * * Returns the size of the string INCLUDING the terminating NUL. - * If the string is too long, returns 'count+1'. + * If the string is too long, returns a number larger than @count. User + * has to check the return value against "> count". * On exception (or invalid count), returns 0. + * + * NOTE! You should basically never use this function. There is + * almost never any valid case for using the length of a user space + * string, since the string can be changed at any time by other + * threads. Use "strncpy_from_user()" instead to get a stable copy + * of the string. */ long strnlen_user(const char __user *str, long count) { diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 4abda074ea45..3c365ab6cf5f 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -537,8 +537,9 @@ EXPORT_SYMBOL_GPL(swiotlb_tbl_map_single); * Allocates bounce buffer and returns its kernel virtual address. */ -phys_addr_t map_single(struct device *hwdev, phys_addr_t phys, size_t size, - enum dma_data_direction dir) +static phys_addr_t +map_single(struct device *hwdev, phys_addr_t phys, size_t size, + enum dma_data_direction dir) { dma_addr_t start_dma_addr = phys_to_dma(hwdev, io_tlb_start); |