Implement ->proc_write_buf() for smp_affinity, smp_affinity_list and default_smp_affinity so procfs copies in what is written before it pins the entry, and parse the masks from that copy. A list of CPUs can be longer than a page on large machines, so the files take as much as memdup_user_nul() could copy in before. Anything larger fails with -EINVAL instead of -ENOMEM.
Signed-off-by: Christian Brauner (Amutable) <[email protected]> --- kernel/irq/proc.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index aa3d5544cfc1..fe683457a088 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -9,6 +9,7 @@ #include <linux/gfp.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> +#include <linux/slab.h> #include <linux/interrupt.h> #include <linux/kernel.h> #include <linux/kernel_stat.h> @@ -134,8 +135,11 @@ static inline int irq_select_affinity_usr(unsigned int irq) } #endif +/* lists of CPUs can outgrow a page, take what memdup_user_nul() took */ +#define IRQ_AFFINITY_WRITE_SIZE (KMALLOC_MAX_SIZE - 1) + static ssize_t write_irq_affinity(int type, struct file *file, - const char __user *buffer, size_t count, loff_t *pos) + char *buffer, size_t count, loff_t *pos) { unsigned int irq = (int)(long)pde_data(file_inode(file)); cpumask_var_t new_value; @@ -148,9 +152,9 @@ static ssize_t write_irq_affinity(int type, struct file *file, return -ENOMEM; if (type) - err = cpumask_parselist_user(buffer, count, new_value); + err = cpulist_parse(buffer, new_value); else - err = cpumask_parse_user(buffer, count, new_value); + err = cpumask_parse(buffer, new_value); if (err) goto free_cpumask; @@ -177,25 +181,27 @@ free_cpumask: } static ssize_t irq_affinity_proc_write(struct file *file, - const char __user *buffer, size_t count, loff_t *pos) + char *buffer, size_t count, loff_t *pos) { return write_irq_affinity(0, file, buffer, count, pos); } static ssize_t irq_affinity_list_proc_write(struct file *file, - const char __user *buffer, size_t count, loff_t *pos) + char *buffer, size_t count, loff_t *pos) { return write_irq_affinity(1, file, buffer, count, pos); } static const struct proc_ops irq_affinity_proc_ops = { .proc_show = irq_affinity_proc_show, - .proc_write = irq_affinity_proc_write, + .proc_write_buf = irq_affinity_proc_write, + .proc_write_size = IRQ_AFFINITY_WRITE_SIZE, }; static const struct proc_ops irq_affinity_list_proc_ops = { .proc_show = irq_affinity_list_proc_show, - .proc_write = irq_affinity_list_proc_write, + .proc_write_buf = irq_affinity_list_proc_write, + .proc_write_size = IRQ_AFFINITY_WRITE_SIZE, }; #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK @@ -217,7 +223,7 @@ static int default_affinity_show(struct seq_file *m, void *v) } static ssize_t default_affinity_write(struct file *file, - const char __user *buffer, size_t count, loff_t *ppos) + char *buffer, size_t count, loff_t *ppos) { cpumask_var_t new_value; int err; @@ -225,7 +231,7 @@ static ssize_t default_affinity_write(struct file *file, if (!zalloc_cpumask_var(&new_value, GFP_KERNEL)) return -ENOMEM; - err = cpumask_parse_user(buffer, count, new_value); + err = cpumask_parse(buffer, new_value); if (err) goto out; @@ -249,7 +255,8 @@ out: static const struct proc_ops default_affinity_proc_ops = { .proc_show = default_affinity_show, - .proc_write = default_affinity_write, + .proc_write_buf = default_affinity_write, + .proc_write_size = IRQ_AFFINITY_WRITE_SIZE, }; static int irq_node_proc_show(struct seq_file *m, void *v) -- 2.53.0
