[PATCH v4 0/2] lib/string_helpers: Introduce parse_int_array_user()
Continuation of recent upstream discussion [1] regarding user string tokenization.
First, parse_int_array_user() is introduced to allow for splitting specified user string into a sequence of integers. Makes use of get_options() internally so the parsing logic is not duplicated.
With that done, redundant parts of the sound driver are removed.
Originally similar functionality was added for the SOF sound driver. As more users are on the horizon, it is desirable to update existing string_helpers code and provide a unified solution.
Changes in v4: - renamed the function to parse_int_array_user() - at the name several local variable names have been reworded to match the above
Changes in v3: - relocated tokenize_user_input() implementation to string_helpers as requested by Matthew
Changes in v2: - reused get_options() so no parsing logic is duplicated - simplified __user variant with help of memdup_user_nul() Both suggested by Andy, thanks for thourough review
[1]: https://lore.kernel.org/alsa-devel/20220707091301.1282291-1-cezary.rojewski@...
Cezary Rojewski (2): lib/string_helpers: Introduce parse_int_array_user() ASoC: SOF: Remove strsplit_u32() and tokenize_input()
include/linux/string_helpers.h | 2 + lib/string_helpers.c | 45 +++++++++++++ sound/soc/sof/sof-client-probes.c | 104 ++++++------------------------ 3 files changed, 65 insertions(+), 86 deletions(-)
Add new helper function to allow for splitting specified user string into a sequence of integers. Internally it makes use of get_options() so the returned sequence contains the integers extracted plus an additional element that begins the sequence and specifies the integers count.
Suggested-by: Andy Shevchenko andy.shevchenko@gmail.com Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Signed-off-by: Cezary Rojewski cezary.rojewski@intel.com --- include/linux/string_helpers.h | 2 ++ lib/string_helpers.c | 45 ++++++++++++++++++++++++++++++++++ 2 files changed, 47 insertions(+)
diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h index 4d72258d42fd..dc2e726fd820 100644 --- a/include/linux/string_helpers.h +++ b/include/linux/string_helpers.h @@ -21,6 +21,8 @@ enum string_size_units { void string_get_size(u64 size, u64 blk_size, enum string_size_units units, char *buf, int len);
+int parse_int_array_user(const char __user *from, size_t count, int **array); + #define UNESCAPE_SPACE BIT(0) #define UNESCAPE_OCTAL BIT(1) #define UNESCAPE_HEX BIT(2) diff --git a/lib/string_helpers.c b/lib/string_helpers.c index 5ed3beb066e6..d0c8f6ecf84c 100644 --- a/lib/string_helpers.c +++ b/lib/string_helpers.c @@ -131,6 +131,51 @@ void string_get_size(u64 size, u64 blk_size, const enum string_size_units units, } EXPORT_SYMBOL(string_get_size);
+/** + * parse_int_array_user - Split string into a sequence of integers + * @from: The user space buffer to read from + * @ppos: The current position in the buffer + * @count: The maximum number of bytes to read + * @tkns: Returned pointer to sequence of integers + * + * On success @tkns is allocated and initialized with a sequence of + * integers extracted from the @from plus an additional element that + * begins the sequence and specifies the integers count. + * + * Caller takes responsibility for freeing @tkns when it is no longer + * needed. + */ +int parse_int_array_user(const char __user *from, size_t count, int **array) +{ + int *ints, nints; + char *buf; + int ret = 0; + + buf = memdup_user_nul(from, count); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + get_options(buf, 0, &nints); + if (!nints) { + ret = -ENOENT; + goto free_buf; + } + + ints = kcalloc(nints + 1, sizeof(*ints), GFP_KERNEL); + if (!ints) { + ret = -ENOMEM; + goto free_buf; + } + + get_options(buf, nints + 1, ints); + *array = ints; + +free_buf: + kfree(buf); + return ret; +} +EXPORT_SYMBOL(parse_int_array_user); + static bool unescape_space(char **src, char **dst) { char *p = *dst, *q = *src;
On 9/2/2022 2:29 PM, Cezary Rojewski wrote:
Add new helper function to allow for splitting specified user string into a sequence of integers. Internally it makes use of get_options() so the returned sequence contains the integers extracted plus an additional element that begins the sequence and specifies the integers count.
Suggested-by: Andy Shevchenko andy.shevchenko@gmail.com Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Signed-off-by: Cezary Rojewski cezary.rojewski@intel.com
include/linux/string_helpers.h | 2 ++ lib/string_helpers.c | 45 ++++++++++++++++++++++++++++++++++ 2 files changed, 47 insertions(+)
diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h index 4d72258d42fd..dc2e726fd820 100644 --- a/include/linux/string_helpers.h +++ b/include/linux/string_helpers.h @@ -21,6 +21,8 @@ enum string_size_units { void string_get_size(u64 size, u64 blk_size, enum string_size_units units, char *buf, int len);
+int parse_int_array_user(const char __user *from, size_t count, int **array);
- #define UNESCAPE_SPACE BIT(0) #define UNESCAPE_OCTAL BIT(1) #define UNESCAPE_HEX BIT(2)
diff --git a/lib/string_helpers.c b/lib/string_helpers.c index 5ed3beb066e6..d0c8f6ecf84c 100644 --- a/lib/string_helpers.c +++ b/lib/string_helpers.c @@ -131,6 +131,51 @@ void string_get_size(u64 size, u64 blk_size, const enum string_size_units units, } EXPORT_SYMBOL(string_get_size);
+/**
- parse_int_array_user - Split string into a sequence of integers
- @from: The user space buffer to read from
- @ppos: The current position in the buffer
There is no such parameter?
- @count: The maximum number of bytes to read
- @tkns: Returned pointer to sequence of integers
s/tkns/array/ ?
- On success @tkns is allocated and initialized with a sequence of
ditto
- integers extracted from the @from plus an additional element that
- begins the sequence and specifies the integers count.
- Caller takes responsibility for freeing @tkns when it is no longer
ditto
- needed.
- */
+int parse_int_array_user(const char __user *from, size_t count, int **array) +{
- int *ints, nints;
- char *buf;
- int ret = 0;
- buf = memdup_user_nul(from, count);
- if (IS_ERR(buf))
return PTR_ERR(buf);- get_options(buf, 0, &nints);
- if (!nints) {
ret = -ENOENT;goto free_buf;- }
- ints = kcalloc(nints + 1, sizeof(*ints), GFP_KERNEL);
- if (!ints) {
ret = -ENOMEM;goto free_buf;- }
- get_options(buf, nints + 1, ints);
- *array = ints;
+free_buf:
- kfree(buf);
- return ret;
+} +EXPORT_SYMBOL(parse_int_array_user);
- static bool unescape_space(char **src, char **dst) { char *p = *dst, *q = *src;
On 2022-09-02 2:23 PM, Amadeusz Sławiński wrote:
On 9/2/2022 2:29 PM, Cezary Rojewski wrote:
...
+/**
- parse_int_array_user - Split string into a sequence of integers
- @from: The user space buffer to read from
- @ppos: The current position in the buffer
There is no such parameter?
- @count: The maximum number of bytes to read
- @tkns: Returned pointer to sequence of integers
s/tkns/array/ ?
- On success @tkns is allocated and initialized with a sequence of
ditto
- integers extracted from the @from plus an additional element that
- begins the sequence and specifies the integers count.
- Caller takes responsibility for freeing @tkns when it is no longer
ditto
- needed.
- */
+int parse_int_array_user(const char __user *from, size_t count, int **array)
Ack. Will send an update shortly.
Regards, Czarek
Make use of global integer-array parsing helper instead of the internal one as both serve same purpose. With that, both strsplit_u32() and tokenize_input() become unused so remove them.
Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Signed-off-by: Cezary Rojewski cezary.rojewski@intel.com --- sound/soc/sof/sof-client-probes.c | 104 ++++++------------------------ 1 file changed, 18 insertions(+), 86 deletions(-)
diff --git a/sound/soc/sof/sof-client-probes.c b/sound/soc/sof/sof-client-probes.c index eb246b823461..aad7fdc665d7 100644 --- a/sound/soc/sof/sof-client-probes.c +++ b/sound/soc/sof/sof-client-probes.c @@ -12,6 +12,8 @@ #include <linux/debugfs.h> #include <linux/module.h> #include <linux/pm_runtime.h> +#include <linux/string_helpers.h> + #include <sound/soc.h> #include <sound/sof/header.h> #include "sof-client.h" @@ -410,79 +412,6 @@ static const struct snd_compress_ops sof_probes_compressed_ops = { .copy = sof_probes_compr_copy, };
-/** - * strsplit_u32 - Split string into sequence of u32 tokens - * @buf: String to split into tokens. - * @delim: String containing delimiter characters. - * @tkns: Returned u32 sequence pointer. - * @num_tkns: Returned number of tokens obtained. - */ -static int strsplit_u32(char *buf, const char *delim, u32 **tkns, size_t *num_tkns) -{ - char *s; - u32 *data, *tmp; - size_t count = 0; - size_t cap = 32; - int ret = 0; - - *tkns = NULL; - *num_tkns = 0; - data = kcalloc(cap, sizeof(*data), GFP_KERNEL); - if (!data) - return -ENOMEM; - - while ((s = strsep(&buf, delim)) != NULL) { - ret = kstrtouint(s, 0, data + count); - if (ret) - goto exit; - if (++count >= cap) { - cap *= 2; - tmp = krealloc(data, cap * sizeof(*data), GFP_KERNEL); - if (!tmp) { - ret = -ENOMEM; - goto exit; - } - data = tmp; - } - } - - if (!count) - goto exit; - *tkns = kmemdup(data, count * sizeof(*data), GFP_KERNEL); - if (!(*tkns)) { - ret = -ENOMEM; - goto exit; - } - *num_tkns = count; - -exit: - kfree(data); - return ret; -} - -static int tokenize_input(const char __user *from, size_t count, - loff_t *ppos, u32 **tkns, size_t *num_tkns) -{ - char *buf; - int ret; - - buf = kmalloc(count + 1, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - ret = simple_write_to_buffer(buf, count, ppos, from, count); - if (ret != count) { - ret = ret >= 0 ? -EIO : ret; - goto exit; - } - - buf[count] = '\0'; - ret = strsplit_u32(buf, ",", tkns, num_tkns); -exit: - kfree(buf); - return ret; -} - static ssize_t sof_probes_dfs_points_read(struct file *file, char __user *to, size_t count, loff_t *ppos) { @@ -548,8 +477,8 @@ sof_probes_dfs_points_write(struct file *file, const char __user *from, struct sof_probes_priv *priv = cdev->data; struct device *dev = &cdev->auxdev.dev; struct sof_probe_point_desc *desc; - size_t num_tkns, bytes; - u32 *tkns; + u32 num_elems, *array; + size_t bytes; int ret, err;
if (priv->extractor_stream_tag == SOF_PROBES_INVALID_NODE_ID) { @@ -557,16 +486,18 @@ sof_probes_dfs_points_write(struct file *file, const char __user *from, return -ENOENT; }
- ret = tokenize_input(from, count, ppos, &tkns, &num_tkns); + ret = parse_int_array_user(from, count, (int **)&array); if (ret < 0) return ret; - bytes = sizeof(*tkns) * num_tkns; - if (!num_tkns || (bytes % sizeof(*desc))) { + + num_elems = *array; + bytes = sizeof(*array) * num_elems; + if (!num_elems || (bytes % sizeof(*desc))) { ret = -EINVAL; goto exit; }
- desc = (struct sof_probe_point_desc *)tkns; + desc = (struct sof_probe_point_desc *)&array[1];
ret = pm_runtime_resume_and_get(dev); if (ret < 0 && ret != -EACCES) { @@ -583,7 +514,7 @@ sof_probes_dfs_points_write(struct file *file, const char __user *from, if (err < 0) dev_err_ratelimited(dev, "debugfs write failed to idle %d\n", err); exit: - kfree(tkns); + kfree(array); return ret; }
@@ -603,8 +534,7 @@ sof_probes_dfs_points_remove_write(struct file *file, const char __user *from, struct sof_client_dev *cdev = file->private_data; struct sof_probes_priv *priv = cdev->data; struct device *dev = &cdev->auxdev.dev; - size_t num_tkns; - u32 *tkns; + u32 num_elems, *array; int ret, err;
if (priv->extractor_stream_tag == SOF_PROBES_INVALID_NODE_ID) { @@ -612,10 +542,12 @@ sof_probes_dfs_points_remove_write(struct file *file, const char __user *from, return -ENOENT; }
- ret = tokenize_input(from, count, ppos, &tkns, &num_tkns); + ret = parse_int_array_user(from, count, (int **)&array); if (ret < 0) return ret; - if (!num_tkns) { + + num_elems = *array; + if (!num_elems) { ret = -EINVAL; goto exit; } @@ -626,7 +558,7 @@ sof_probes_dfs_points_remove_write(struct file *file, const char __user *from, goto exit; }
- ret = sof_probes_points_remove(cdev, tkns, num_tkns); + ret = sof_probes_points_remove(cdev, &array[1], num_elems); if (!ret) ret = count;
@@ -635,7 +567,7 @@ sof_probes_dfs_points_remove_write(struct file *file, const char __user *from, if (err < 0) dev_err_ratelimited(dev, "debugfs write failed to idle %d\n", err); exit: - kfree(tkns); + kfree(array); return ret; }
participants (2)
-
Amadeusz Sławiński -
Cezary Rojewski