diff options
Diffstat (limited to 'arch/powerpc/platforms')
-rw-r--r-- | arch/powerpc/platforms/pseries/papr-sysparm.c | 158 |
1 files changed, 156 insertions, 2 deletions
diff --git a/arch/powerpc/platforms/pseries/papr-sysparm.c b/arch/powerpc/platforms/pseries/papr-sysparm.c index a1e7aeac7416..7063ce8884e4 100644 --- a/arch/powerpc/platforms/pseries/papr-sysparm.c +++ b/arch/powerpc/platforms/pseries/papr-sysparm.c @@ -2,14 +2,20 @@ #define pr_fmt(fmt) "papr-sysparm: " fmt +#include <linux/anon_inodes.h> #include <linux/bug.h> +#include <linux/file.h> +#include <linux/fs.h> #include <linux/init.h> #include <linux/kernel.h> +#include <linux/miscdevice.h> #include <linux/printk.h> #include <linux/slab.h> -#include <asm/rtas.h> +#include <linux/uaccess.h> +#include <asm/machdep.h> #include <asm/papr-sysparm.h> #include <asm/rtas-work-area.h> +#include <asm/rtas.h> struct papr_sysparm_buf *papr_sysparm_buf_alloc(void) { @@ -87,7 +93,6 @@ static bool papr_sysparm_buf_can_submit(const struct papr_sysparm_buf *buf) * * Return: 0 on success, -errno otherwise. @buf is unmodified on error. */ - int papr_sysparm_get(papr_sysparm_t param, struct papr_sysparm_buf *buf) { const s32 token = rtas_function_token(RTAS_FN_IBM_GET_SYSTEM_PARAMETER); @@ -196,3 +201,152 @@ int papr_sysparm_set(papr_sysparm_t param, const struct papr_sysparm_buf *buf) return ret; } + +static struct papr_sysparm_buf * +papr_sysparm_buf_from_user(const struct papr_sysparm_io_block __user *user_iob) +{ + struct papr_sysparm_buf *kern_spbuf; + long err; + u16 len; + + /* + * The length of valid data that userspace claims to be in + * user_iob->data[]. + */ + if (get_user(len, &user_iob->length)) + return ERR_PTR(-EFAULT); + + static_assert(sizeof(user_iob->data) >= PAPR_SYSPARM_MAX_INPUT); + static_assert(sizeof(kern_spbuf->val) >= PAPR_SYSPARM_MAX_INPUT); + + if (len > PAPR_SYSPARM_MAX_INPUT) + return ERR_PTR(-EINVAL); + + kern_spbuf = papr_sysparm_buf_alloc(); + if (!kern_spbuf) + return ERR_PTR(-ENOMEM); + + papr_sysparm_buf_set_length(kern_spbuf, len); + + if (len > 0 && copy_from_user(kern_spbuf->val, user_iob->data, len)) { + err = -EFAULT; + goto free_sysparm_buf; + } + + return kern_spbuf; + +free_sysparm_buf: + papr_sysparm_buf_free(kern_spbuf); + return ERR_PTR(err); +} + +static int papr_sysparm_buf_to_user(const struct papr_sysparm_buf *kern_spbuf, + struct papr_sysparm_io_block __user *user_iob) +{ + u16 len_out = papr_sysparm_buf_get_length(kern_spbuf); + + if (put_user(len_out, &user_iob->length)) + return -EFAULT; + + static_assert(sizeof(user_iob->data) >= PAPR_SYSPARM_MAX_OUTPUT); + static_assert(sizeof(kern_spbuf->val) >= PAPR_SYSPARM_MAX_OUTPUT); + + if (copy_to_user(user_iob->data, kern_spbuf->val, PAPR_SYSPARM_MAX_OUTPUT)) + return -EFAULT; + + return 0; +} + +static long papr_sysparm_ioctl_get(struct papr_sysparm_io_block __user *user_iob) +{ + struct papr_sysparm_buf *kern_spbuf; + papr_sysparm_t param; + long ret; + + if (get_user(param.token, &user_iob->parameter)) + return -EFAULT; + + kern_spbuf = papr_sysparm_buf_from_user(user_iob); + if (IS_ERR(kern_spbuf)) + return PTR_ERR(kern_spbuf); + + ret = papr_sysparm_get(param, kern_spbuf); + if (ret) + goto free_sysparm_buf; + + ret = papr_sysparm_buf_to_user(kern_spbuf, user_iob); + if (ret) + goto free_sysparm_buf; + + ret = 0; + +free_sysparm_buf: + papr_sysparm_buf_free(kern_spbuf); + return ret; +} + + +static long papr_sysparm_ioctl_set(struct papr_sysparm_io_block __user *user_iob) +{ + struct papr_sysparm_buf *kern_spbuf; + papr_sysparm_t param; + long ret; + + if (get_user(param.token, &user_iob->parameter)) + return -EFAULT; + + kern_spbuf = papr_sysparm_buf_from_user(user_iob); + if (IS_ERR(kern_spbuf)) + return PTR_ERR(kern_spbuf); + + ret = papr_sysparm_set(param, kern_spbuf); + if (ret) + goto free_sysparm_buf; + + ret = 0; + +free_sysparm_buf: + papr_sysparm_buf_free(kern_spbuf); + return ret; +} + +static long papr_sysparm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) +{ + void __user *argp = (__force void __user *)arg; + long ret; + + switch (ioctl) { + case PAPR_SYSPARM_IOC_GET: + ret = papr_sysparm_ioctl_get(argp); + break; + case PAPR_SYSPARM_IOC_SET: + if (filp->f_mode & FMODE_WRITE) + ret = papr_sysparm_ioctl_set(argp); + else + ret = -EBADF; + break; + default: + ret = -ENOIOCTLCMD; + break; + } + return ret; +} + +static const struct file_operations papr_sysparm_ops = { + .unlocked_ioctl = papr_sysparm_ioctl, +}; + +static struct miscdevice papr_sysparm_dev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "papr-sysparm", + .fops = &papr_sysparm_ops, +}; + +static __init int papr_sysparm_init(void) +{ + if (!rtas_function_implemented(RTAS_FN_IBM_GET_SYSTEM_PARAMETER)) + return -ENODEV; + + return misc_register(&papr_sysparm_dev); +} +machine_device_initcall(pseries, papr_sysparm_init); |