From e2e40f2c1ed433c5e224525c8c862fd32e5d3df2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 22 Feb 2015 08:58:50 -0800 Subject: fs: move struct kiocb to fs.h struct kiocb now is a generic I/O container, so move it to fs.h. Also do a #include diet for aio.h while we're at it. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro --- kernel/sysctl.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 88ea2d6e0031..83d907afb4a6 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -19,6 +19,7 @@ */ #include +#include #include #include #include -- cgit v1.2.3 From 195daf665a6299de98a4da3843fed2dd9de19d3a Mon Sep 17 00:00:00 2001 From: Ulrich Obergfell Date: Tue, 14 Apr 2015 15:44:13 -0700 Subject: watchdog: enable the new user interface of the watchdog mechanism With the current user interface of the watchdog mechanism it is only possible to disable or enable both lockup detectors at the same time. This series introduces new kernel parameters and changes the semantics of some existing kernel parameters, so that the hard lockup detector and the soft lockup detector can be disabled or enabled individually. With this series applied, the user interface is as follows. - parameters in /proc/sys/kernel . soft_watchdog This is a new parameter to control and examine the run state of the soft lockup detector. . nmi_watchdog The semantics of this parameter have changed. It can now be used to control and examine the run state of the hard lockup detector. . watchdog This parameter is still available to control the run state of both lockup detectors at the same time. If this parameter is examined, it shows the logical OR of soft_watchdog and nmi_watchdog. . watchdog_thresh The semantics of this parameter are not affected by the patch. - kernel command line parameters . nosoftlockup The semantics of this parameter have changed. It can now be used to disable the soft lockup detector at boot time. . nmi_watchdog=0 or nmi_watchdog=1 Disable or enable the hard lockup detector at boot time. The patch introduces '=1' as a new option. . nowatchdog The semantics of this parameter are not affected by the patch. It is still available to disable both lockup detectors at boot time. Also, remove the proc_dowatchdog() function which is no longer needed. [dzickus@redhat.com: wrote changelog] [dzickus@redhat.com: update documentation for kernel params and sysctl] Signed-off-by: Ulrich Obergfell Signed-off-by: Don Zickus Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/kernel-parameters.txt | 6 ++- Documentation/sysctl/kernel.txt | 62 +++++++++++++++++++++++----- include/linux/nmi.h | 2 - kernel/sysctl.c | 35 +++++++++++----- kernel/watchdog.c | 81 ++++++++----------------------------- 5 files changed, 97 insertions(+), 89 deletions(-) (limited to 'kernel/sysctl.c') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 01aa47d3b6ab..71eecb263250 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2236,8 +2236,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels Format: [panic,][nopanic,][num] - Valid num: 0 + Valid num: 0 or 1 0 - turn nmi_watchdog off + 1 - turn nmi_watchdog on When panic is specified, panic when an NMI watchdog timeout occurs (or 'nopanic' to override the opposite default). @@ -2464,7 +2465,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nousb [USB] Disable the USB subsystem - nowatchdog [KNL] Disable the lockup detector (NMI watchdog). + nowatchdog [KNL] Disable both lockup detectors, i.e. + soft-lockup and NMI watchdog (hard-lockup). nowb [ARM] diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 83ab25660fc9..99d7eb3a1416 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -77,12 +77,14 @@ show up in /proc/sys/kernel: - shmmax [ sysv ipc ] - shmmni - softlockup_all_cpu_backtrace +- soft_watchdog - stop-a [ SPARC only ] - sysrq ==> Documentation/sysrq.txt - sysctl_writes_strict - tainted - threads-max - unknown_nmi_panic +- watchdog - watchdog_thresh - version @@ -417,16 +419,23 @@ successful IPC object allocation. nmi_watchdog: -Enables/Disables the NMI watchdog on x86 systems. When the value is -non-zero the NMI watchdog is enabled and will continuously test all -online cpus to determine whether or not they are still functioning -properly. Currently, passing "nmi_watchdog=" parameter at boot time is -required for this function to work. +This parameter can be used to control the NMI watchdog +(i.e. the hard lockup detector) on x86 systems. -If LAPIC NMI watchdog method is in use (nmi_watchdog=2 kernel -parameter), the NMI watchdog shares registers with oprofile. By -disabling the NMI watchdog, oprofile may have more registers to -utilize. + 0 - disable the hard lockup detector + 1 - enable the hard lockup detector + +The hard lockup detector monitors each CPU for its ability to respond to +timer interrupts. The mechanism utilizes CPU performance counter registers +that are programmed to generate Non-Maskable Interrupts (NMIs) periodically +while a CPU is busy. Hence, the alternative name 'NMI watchdog'. + +The NMI watchdog is disabled by default if the kernel is running as a guest +in a KVM virtual machine. This default can be overridden by adding + + nmi_watchdog=1 + +to the guest kernel command line (see Documentation/kernel-parameters.txt). ============================================================== @@ -816,6 +825,22 @@ NMI. ============================================================== +soft_watchdog + +This parameter can be used to control the soft lockup detector. + + 0 - disable the soft lockup detector + 1 - enable the soft lockup detector + +The soft lockup detector monitors CPUs for threads that are hogging the CPUs +without rescheduling voluntarily, and thus prevent the 'watchdog/N' threads +from running. The mechanism depends on the CPUs ability to respond to timer +interrupts which are needed for the 'watchdog/N' threads to be woken up by +the watchdog timer function, otherwise the NMI watchdog - if enabled - can +detect a hard lockup condition. + +============================================================== + tainted: Non-zero if the kernel has been tainted. Numeric values, which @@ -858,6 +883,25 @@ example. If a system hangs up, try pressing the NMI switch. ============================================================== +watchdog: + +This parameter can be used to disable or enable the soft lockup detector +_and_ the NMI watchdog (i.e. the hard lockup detector) at the same time. + + 0 - disable both lockup detectors + 1 - enable both lockup detectors + +The soft lockup detector and the NMI watchdog can also be disabled or +enabled individually, using the soft_watchdog and nmi_watchdog parameters. +If the watchdog parameter is read, for example by executing + + cat /proc/sys/kernel/watchdog + +the output of this command (0 or 1) shows the logical OR of soft_watchdog +and nmi_watchdog. + +============================================================== + watchdog_thresh: This value can be used to control the frequency of hrtimer and NMI diff --git a/include/linux/nmi.h b/include/linux/nmi.h index 5b5450585b8a..0426357297d5 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -82,8 +82,6 @@ extern int proc_soft_watchdog(struct ctl_table *, int , void __user *, size_t *, loff_t *); extern int proc_watchdog_thresh(struct ctl_table *, int , void __user *, size_t *, loff_t *); -extern int proc_dowatchdog(struct ctl_table *, int , - void __user *, size_t *, loff_t *); #endif #ifdef CONFIG_HAVE_ACPI_APEI_NMI diff --git a/kernel/sysctl.c b/kernel/sysctl.c index ce410bb9f2e1..245e7dcc3741 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -846,7 +846,7 @@ static struct ctl_table kern_table[] = { .data = &watchdog_user_enabled, .maxlen = sizeof (int), .mode = 0644, - .proc_handler = proc_dowatchdog, + .proc_handler = proc_watchdog, .extra1 = &zero, .extra2 = &one, }, @@ -855,10 +855,32 @@ static struct ctl_table kern_table[] = { .data = &watchdog_thresh, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dowatchdog, + .proc_handler = proc_watchdog_thresh, .extra1 = &zero, .extra2 = &sixty, }, + { + .procname = "nmi_watchdog", + .data = &nmi_watchdog_enabled, + .maxlen = sizeof (int), + .mode = 0644, + .proc_handler = proc_nmi_watchdog, + .extra1 = &zero, +#if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR) + .extra2 = &one, +#else + .extra2 = &zero, +#endif + }, + { + .procname = "soft_watchdog", + .data = &soft_watchdog_enabled, + .maxlen = sizeof (int), + .mode = 0644, + .proc_handler = proc_soft_watchdog, + .extra1 = &zero, + .extra2 = &one, + }, { .procname = "softlockup_panic", .data = &softlockup_panic, @@ -879,15 +901,6 @@ static struct ctl_table kern_table[] = { .extra2 = &one, }, #endif /* CONFIG_SMP */ - { - .procname = "nmi_watchdog", - .data = &watchdog_user_enabled, - .maxlen = sizeof (int), - .mode = 0644, - .proc_handler = proc_dowatchdog, - .extra1 = &zero, - .extra2 = &one, - }, #endif #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) { diff --git a/kernel/watchdog.c b/kernel/watchdog.c index fd2b6dc14486..63d702885686 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -110,15 +110,9 @@ static int __init hardlockup_panic_setup(char *str) else if (!strncmp(str, "nopanic", 7)) hardlockup_panic = 0; else if (!strncmp(str, "0", 1)) - watchdog_user_enabled = 0; - else if (!strncmp(str, "1", 1) || !strncmp(str, "2", 1)) { - /* - * Setting 'nmi_watchdog=1' or 'nmi_watchdog=2' (legacy option) - * has the same effect. - */ - watchdog_user_enabled = 1; - watchdog_enable_hardlockup_detector(true); - } + watchdog_enabled &= ~NMI_WATCHDOG_ENABLED; + else if (!strncmp(str, "1", 1)) + watchdog_enabled |= NMI_WATCHDOG_ENABLED; return 1; } __setup("nmi_watchdog=", hardlockup_panic_setup); @@ -137,19 +131,18 @@ __setup("softlockup_panic=", softlockup_panic_setup); static int __init nowatchdog_setup(char *str) { - watchdog_user_enabled = 0; + watchdog_enabled = 0; return 1; } __setup("nowatchdog", nowatchdog_setup); -/* deprecated */ static int __init nosoftlockup_setup(char *str) { - watchdog_user_enabled = 0; + watchdog_enabled &= ~SOFT_WATCHDOG_ENABLED; return 1; } __setup("nosoftlockup", nosoftlockup_setup); -/* */ + #ifdef CONFIG_SMP static int __init softlockup_all_cpu_backtrace_setup(char *str) { @@ -264,10 +257,11 @@ static int is_softlockup(unsigned long touch_ts) { unsigned long now = get_timestamp(); - /* Warn about unreasonable delays: */ - if (time_after(now, touch_ts + get_softlockup_thresh())) - return now - touch_ts; - + if (watchdog_enabled & SOFT_WATCHDOG_ENABLED) { + /* Warn about unreasonable delays. */ + if (time_after(now, touch_ts + get_softlockup_thresh())) + return now - touch_ts; + } return 0; } @@ -532,6 +526,10 @@ static int watchdog_nmi_enable(unsigned int cpu) struct perf_event_attr *wd_attr; struct perf_event *event = per_cpu(watchdog_ev, cpu); + /* nothing to do if the hard lockup detector is disabled */ + if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED)) + goto out; + /* * Some kernels need to default hard lockup detection to * 'disabled', for example a guest on a hypervisor. @@ -856,59 +854,12 @@ out: mutex_unlock(&watchdog_proc_mutex); return err; } - -/* - * proc handler for /proc/sys/kernel/nmi_watchdog,watchdog_thresh - */ - -int proc_dowatchdog(struct ctl_table *table, int write, - void __user *buffer, size_t *lenp, loff_t *ppos) -{ - int err, old_thresh, old_enabled; - bool old_hardlockup; - - mutex_lock(&watchdog_proc_mutex); - old_thresh = ACCESS_ONCE(watchdog_thresh); - old_enabled = ACCESS_ONCE(watchdog_user_enabled); - old_hardlockup = watchdog_hardlockup_detector_is_enabled(); - - err = proc_dointvec_minmax(table, write, buffer, lenp, ppos); - if (err || !write) - goto out; - - set_sample_period(); - /* - * Watchdog threads shouldn't be enabled if they are - * disabled. The 'watchdog_running' variable check in - * watchdog_*_all_cpus() function takes care of this. - */ - if (watchdog_user_enabled && watchdog_thresh) { - /* - * Prevent a change in watchdog_thresh accidentally overriding - * the enablement of the hardlockup detector. - */ - if (watchdog_user_enabled != old_enabled) - watchdog_enable_hardlockup_detector(true); - err = watchdog_enable_all_cpus(old_thresh != watchdog_thresh); - } else - watchdog_disable_all_cpus(); - - /* Restore old values on failure */ - if (err) { - watchdog_thresh = old_thresh; - watchdog_user_enabled = old_enabled; - watchdog_enable_hardlockup_detector(old_hardlockup); - } -out: - mutex_unlock(&watchdog_proc_mutex); - return err; -} #endif /* CONFIG_SYSCTL */ void __init lockup_detector_init(void) { set_sample_period(); - if (watchdog_user_enabled) + if (watchdog_enabled) watchdog_enable_all_cpus(false); } -- cgit v1.2.3 From 5bbe3547aa3ba5242366a322a28996872301b703 Mon Sep 17 00:00:00 2001 From: Eric B Munson Date: Wed, 15 Apr 2015 16:13:20 -0700 Subject: mm: allow compaction of unevictable pages Currently, pages which are marked as unevictable are protected from compaction, but not from other types of migration. The POSIX real time extension explicitly states that mlock() will prevent a major page fault, but the spirit of this is that mlock() should give a process the ability to control sources of latency, including minor page faults. However, the mlock manpage only explicitly says that a locked page will not be written to swap and this can cause some confusion. The compaction code today does not give a developer who wants to avoid swap but wants to have large contiguous areas available any method to achieve this state. This patch introduces a sysctl for controlling compaction behavior with respect to the unevictable lru. Users who demand no page faults after a page is present can set compact_unevictable_allowed to 0 and users who need the large contiguous areas can enable compaction on locked memory by leaving the default value of 1. To illustrate this problem I wrote a quick test program that mmaps a large number of 1MB files filled with random data. These maps are created locked and read only. Then every other mmap is unmapped and I attempt to allocate huge pages to the static huge page pool. When the compact_unevictable_allowed sysctl is 0, I cannot allocate hugepages after fragmenting memory. When the value is set to 1, allocations succeed. Signed-off-by: Eric B Munson Acked-by: Michal Hocko Acked-by: Vlastimil Babka Acked-by: Christoph Lameter Acked-by: David Rientjes Acked-by: Rik van Riel Cc: Vlastimil Babka Cc: Thomas Gleixner Cc: Christoph Lameter Cc: Peter Zijlstra Cc: Mel Gorman Cc: David Rientjes Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/sysctl/vm.txt | 11 +++++++++++ include/linux/compaction.h | 1 + kernel/sysctl.c | 9 +++++++++ mm/compaction.c | 7 +++++++ 4 files changed, 28 insertions(+) (limited to 'kernel/sysctl.c') diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 902b4574acfb..9832ec52f859 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -21,6 +21,7 @@ Currently, these files are in /proc/sys/vm: - admin_reserve_kbytes - block_dump - compact_memory +- compact_unevictable_allowed - dirty_background_bytes - dirty_background_ratio - dirty_bytes @@ -106,6 +107,16 @@ huge pages although processes will also directly compact memory as required. ============================================================== +compact_unevictable_allowed + +Available only when CONFIG_COMPACTION is set. When set to 1, compaction is +allowed to examine the unevictable lru (mlocked pages) for pages to compact. +This should be used on systems where stalls for minor page faults are an +acceptable trade for large contiguous free memory. Set to 0 to prevent +compaction from moving pages that are unevictable. Default value is 1. + +============================================================== + dirty_background_bytes Contains the amount of dirty memory at which the background kernel diff --git a/include/linux/compaction.h b/include/linux/compaction.h index a014559e4a49..aa8f61cf3a19 100644 --- a/include/linux/compaction.h +++ b/include/linux/compaction.h @@ -34,6 +34,7 @@ extern int sysctl_compaction_handler(struct ctl_table *table, int write, extern int sysctl_extfrag_threshold; extern int sysctl_extfrag_handler(struct ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos); +extern int sysctl_compact_unevictable_allowed; extern int fragmentation_index(struct zone *zone, unsigned int order); extern unsigned long try_to_compact_pages(gfp_t gfp_mask, unsigned int order, diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8c0eabd41886..42b7fc2860c1 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1335,6 +1335,15 @@ static struct ctl_table vm_table[] = { .extra1 = &min_extfrag_threshold, .extra2 = &max_extfrag_threshold, }, + { + .procname = "compact_unevictable_allowed", + .data = &sysctl_compact_unevictable_allowed, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = &zero, + .extra2 = &one, + }, #endif /* CONFIG_COMPACTION */ { diff --git a/mm/compaction.c b/mm/compaction.c index a18201a8124e..570426edcadf 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1046,6 +1046,12 @@ typedef enum { ISOLATE_SUCCESS, /* Pages isolated, migrate */ } isolate_migrate_t; +/* + * Allow userspace to control policy on scanning the unevictable LRU for + * compactable pages. + */ +int sysctl_compact_unevictable_allowed __read_mostly = 1; + /* * Isolate all pages that can be migrated from the first suitable block, * starting at the block pointed to by the migrate scanner pfn within @@ -1057,6 +1063,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, unsigned long low_pfn, end_pfn; struct page *page; const isolate_mode_t isolate_mode = + (sysctl_compact_unevictable_allowed ? ISOLATE_UNEVICTABLE : 0) | (cc->mode == MIGRATE_ASYNC ? ISOLATE_ASYNC_MIGRATE : 0); /* -- cgit v1.2.3 From 16db3d3f1170fb0efca652c9378ce7c5f5cb4232 Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Thu, 16 Apr 2015 12:47:50 -0700 Subject: kernel/sysctl.c: threads-max observe limits Users can change the maximum number of threads by writing to /proc/sys/kernel/threads-max. With the patch the value entered is checked against the same limits that apply when fork_init is called. Signed-off-by: Heinrich Schuchardt Cc: Oleg Nesterov Cc: Ingo Molnar Cc: Guenter Roeck Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/sysctl.h | 3 +++ kernel/fork.c | 31 +++++++++++++++++++++++++++++-- kernel/sysctl.c | 6 ++---- 3 files changed, 34 insertions(+), 6 deletions(-) (limited to 'kernel/sysctl.c') diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index b7361f831226..795d5fea5697 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -212,4 +212,7 @@ static inline void setup_sysctl_set(struct ctl_table_set *p, #endif /* CONFIG_SYSCTL */ +int sysctl_max_threads(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, loff_t *ppos); + #endif /* _LINUX_SYSCTL_H */ diff --git a/kernel/fork.c b/kernel/fork.c index c7f2e1a4187a..8807a129711b 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -74,6 +74,7 @@ #include #include #include +#include #include #include @@ -266,7 +267,7 @@ void __init __weak arch_task_cache_init(void) { } /* * set_max_threads */ -static void set_max_threads(void) +static void set_max_threads(unsigned int max_threads_suggested) { u64 threads; @@ -280,6 +281,9 @@ static void set_max_threads(void) threads = div64_u64((u64) totalram_pages * (u64) PAGE_SIZE, (u64) THREAD_SIZE * 8UL); + if (threads > max_threads_suggested) + threads = max_threads_suggested; + max_threads = clamp_t(u64, threads, MIN_THREADS, MAX_THREADS); } @@ -298,7 +302,7 @@ void __init fork_init(void) /* do the arch specific task caches init */ arch_task_cache_init(); - set_max_threads(); + set_max_threads(MAX_THREADS); init_task.signal->rlim[RLIMIT_NPROC].rlim_cur = max_threads/2; init_task.signal->rlim[RLIMIT_NPROC].rlim_max = max_threads/2; @@ -2020,3 +2024,26 @@ int unshare_files(struct files_struct **displaced) task_unlock(task); return 0; } + +int sysctl_max_threads(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + struct ctl_table t; + int ret; + int threads = max_threads; + int min = MIN_THREADS; + int max = MAX_THREADS; + + t = *table; + t.data = &threads; + t.extra1 = &min; + t.extra2 = &max; + + ret = proc_dointvec_minmax(&t, write, buffer, lenp, ppos); + if (ret || !write) + return ret; + + set_max_threads(threads); + + return 0; +} diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 42b7fc2860c1..3c0998426b57 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -93,11 +93,9 @@ #include #endif - #if defined(CONFIG_SYSCTL) /* External variables not in a header file. */ -extern int max_threads; extern int suid_dumpable; #ifdef CONFIG_COREDUMP extern int core_uses_pid; @@ -710,10 +708,10 @@ static struct ctl_table kern_table[] = { #endif { .procname = "threads-max", - .data = &max_threads, + .data = NULL, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec, + .proc_handler = sysctl_max_threads, }, { .procname = "random", -- cgit v1.2.3 From 230633d109e35b0a24277498e773edeb79b4a331 Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Thu, 16 Apr 2015 12:48:07 -0700 Subject: kernel/sysctl.c: detect overflows when converting to int When converting unsigned long to int overflows may occur. These currently are not detected when writing to the sysctl file system. E.g. on a system where int has 32 bits and long has 64 bits echo 0x800001234 > /proc/sys/kernel/threads-max has the same effect as echo 0x1234 > /proc/sys/kernel/threads-max The patch adds the missing check in do_proc_dointvec_conv. With the patch an overflow will result in an error EINVAL when writing to the the sysctl file system. Signed-off-by: Heinrich Schuchardt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 3c0998426b57..2082b1a88fb9 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1981,7 +1981,15 @@ static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp, int write, void *data) { if (write) { - *valp = *negp ? -*lvalp : *lvalp; + if (*negp) { + if (*lvalp > (unsigned long) INT_MAX + 1) + return -EINVAL; + *valp = -*lvalp; + } else { + if (*lvalp > (unsigned long) INT_MAX) + return -EINVAL; + *valp = *lvalp; + } } else { int val = *valp; if (val < 0) { -- cgit v1.2.3