From 32927393dc1ccd60fb2bdc05b9e8e88753761469 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 24 Apr 2020 08:43:38 +0200 Subject: sysctl: pass kernel pointers to ->proc_handler Instead of having all the sysctl handlers deal with user pointers, which is rather hairy in terms of the BPF interaction, copy the input to and from userspace in common code. This also means that the strings are always NUL-terminated by the common code, making the API a little bit safer. As most handler just pass through the data to one of the common handlers a lot of the changes are mechnical. Signed-off-by: Christoph Hellwig Acked-by: Andrey Ignatov Signed-off-by: Al Viro --- kernel/events/callchain.c | 2 +- kernel/events/core.c | 6 ++---- 2 files changed, 3 insertions(+), 5 deletions(-) (limited to 'kernel/events') diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c index c2b41a263166..bdb1533ada81 100644 --- a/kernel/events/callchain.c +++ b/kernel/events/callchain.c @@ -236,7 +236,7 @@ exit_put: * sysctl_perf_event_max_contexts_per_stack. */ int perf_event_max_stack_handler(struct ctl_table *table, int write, - void __user *buffer, size_t *lenp, loff_t *ppos) + void *buffer, size_t *lenp, loff_t *ppos) { int *value = table->data; int new_value = *value, ret; diff --git a/kernel/events/core.c b/kernel/events/core.c index bc9b98a9af9a..f86d46f2c4d9 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -437,8 +437,7 @@ static void update_perf_cpu_limits(void) static bool perf_rotate_context(struct perf_cpu_context *cpuctx); int perf_proc_update_handler(struct ctl_table *table, int write, - void __user *buffer, size_t *lenp, - loff_t *ppos) + void *buffer, size_t *lenp, loff_t *ppos) { int ret; int perf_cpu = sysctl_perf_cpu_time_max_percent; @@ -462,8 +461,7 @@ int perf_proc_update_handler(struct ctl_table *table, int write, int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, - void __user *buffer, size_t *lenp, - loff_t *ppos) + void *buffer, size_t *lenp, loff_t *ppos) { int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); -- cgit v1.2.3