From 8ecc2951534af10e04ddb5e5ff5c6d217b79f5c2 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Fri, 15 Jan 2010 17:01:12 -0800 Subject: kfifo: use void * pointers for user buffers The pointers to user buffers are currently unsigned char *, which requires a lot of casting in the caller for any non-char typed buffers. Use void * instead. Signed-off-by: Andi Kleen Acked-by: Stefani Seibold Cc: Roland Dreier Cc: Dmitry Torokhov Cc: Andy Walls Cc: Vikram Dhillon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kfifo.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'kernel/kfifo.c') diff --git a/kernel/kfifo.c b/kernel/kfifo.c index e92d519f93b..ab615e69505 100644 --- a/kernel/kfifo.c +++ b/kernel/kfifo.c @@ -28,7 +28,7 @@ #include #include -static void _kfifo_init(struct kfifo *fifo, unsigned char *buffer, +static void _kfifo_init(struct kfifo *fifo, void *buffer, unsigned int size) { fifo->buffer = buffer; @@ -44,7 +44,7 @@ static void _kfifo_init(struct kfifo *fifo, unsigned char *buffer, * @size: the size of the internal buffer, this have to be a power of 2. * */ -void kfifo_init(struct kfifo *fifo, unsigned char *buffer, unsigned int size) +void kfifo_init(struct kfifo *fifo, void *buffer, unsigned int size) { /* size must be a power of 2 */ BUG_ON(!is_power_of_2(size)); @@ -235,7 +235,7 @@ EXPORT_SYMBOL(__kfifo_in_n); * Note that with only one concurrent reader and one concurrent * writer, you don't need extra locking to use these functions. */ -unsigned int kfifo_in(struct kfifo *fifo, const unsigned char *from, +unsigned int kfifo_in(struct kfifo *fifo, const void *from, unsigned int len) { len = min(kfifo_avail(fifo), len); @@ -277,7 +277,7 @@ EXPORT_SYMBOL(__kfifo_out_n); * Note that with only one concurrent reader and one concurrent * writer, you don't need extra locking to use these functions. */ -unsigned int kfifo_out(struct kfifo *fifo, unsigned char *to, unsigned int len) +unsigned int kfifo_out(struct kfifo *fifo, void *to, unsigned int len) { len = min(kfifo_len(fifo), len); -- cgit v1.2.3-18-g5258 From 64ce1037c5434b1d036cd99ecaee6e00496bc2e9 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Fri, 15 Jan 2010 17:01:15 -0800 Subject: kfifo: sanitize *_user error handling Right now for kfifo_*_user it's not easily possible to distingush between a user copy failing and the FIFO not containing enough data. The problem is that both conditions are multiplexed into the same return code. Avoid this by moving the "copy length" into a separate output parameter and only return 0/-EFAULT in the main return value. I didn't fully adapt the weird "record" variants, those seem to be unused anyways and were rather messy (should they be just removed?) I would appreciate some double checking if I did all the conversions correctly. Signed-off-by: Andi Kleen Cc: Stefani Seibold Cc: Roland Dreier Cc: Dmitry Torokhov Cc: Andy Walls Cc: Vikram Dhillon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kfifo.c | 76 +++++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 49 insertions(+), 27 deletions(-) (limited to 'kernel/kfifo.c') diff --git a/kernel/kfifo.c b/kernel/kfifo.c index ab615e69505..b50bb622e8b 100644 --- a/kernel/kfifo.c +++ b/kernel/kfifo.c @@ -159,8 +159,9 @@ static inline void __kfifo_out_data(struct kfifo *fifo, memcpy(to + l, fifo->buffer, len - l); } -static inline unsigned int __kfifo_from_user_data(struct kfifo *fifo, - const void __user *from, unsigned int len, unsigned int off) +static inline int __kfifo_from_user_data(struct kfifo *fifo, + const void __user *from, unsigned int len, unsigned int off, + unsigned *lenout) { unsigned int l; int ret; @@ -177,16 +178,20 @@ static inline unsigned int __kfifo_from_user_data(struct kfifo *fifo, /* first put the data starting from fifo->in to buffer end */ l = min(len, fifo->size - off); ret = copy_from_user(fifo->buffer + off, from, l); - - if (unlikely(ret)) - return ret + len - l; + if (unlikely(ret)) { + *lenout = ret; + return -EFAULT; + } + *lenout = l; /* then put the rest (if any) at the beginning of the buffer */ - return copy_from_user(fifo->buffer, from + l, len - l); + ret = copy_from_user(fifo->buffer, from + l, len - l); + *lenout += ret ? ret : len - l; + return ret ? -EFAULT : 0; } -static inline unsigned int __kfifo_to_user_data(struct kfifo *fifo, - void __user *to, unsigned int len, unsigned int off) +static inline int __kfifo_to_user_data(struct kfifo *fifo, + void __user *to, unsigned int len, unsigned int off, unsigned *lenout) { unsigned int l; int ret; @@ -203,12 +208,21 @@ static inline unsigned int __kfifo_to_user_data(struct kfifo *fifo, /* first get the data from fifo->out until the end of the buffer */ l = min(len, fifo->size - off); ret = copy_to_user(to, fifo->buffer + off, l); - - if (unlikely(ret)) - return ret + len - l; + *lenout = l; + if (unlikely(ret)) { + *lenout -= ret; + return -EFAULT; + } /* then get the rest (if any) from the beginning of the buffer */ - return copy_to_user(to + l, fifo->buffer, len - l); + len -= l; + ret = copy_to_user(to + l, fifo->buffer, len); + if (unlikely(ret)) { + *lenout += len - ret; + return -EFAULT; + } + *lenout += len; + return 0; } unsigned int __kfifo_in_n(struct kfifo *fifo, @@ -299,10 +313,13 @@ EXPORT_SYMBOL(__kfifo_out_generic); unsigned int __kfifo_from_user_n(struct kfifo *fifo, const void __user *from, unsigned int len, unsigned int recsize) { + unsigned total; + if (kfifo_avail(fifo) < len + recsize) return len + 1; - return __kfifo_from_user_data(fifo, from, len, recsize); + __kfifo_from_user_data(fifo, from, len, recsize, &total); + return total; } EXPORT_SYMBOL(__kfifo_from_user_n); @@ -313,18 +330,21 @@ EXPORT_SYMBOL(__kfifo_from_user_n); * @len: the length of the data to be added. * * This function copies at most @len bytes from the @from into the - * FIFO depending and returns the number of copied bytes. + * FIFO depending and returns -EFAULT/0. * * Note that with only one concurrent reader and one concurrent * writer, you don't need extra locking to use these functions. */ -unsigned int kfifo_from_user(struct kfifo *fifo, - const void __user *from, unsigned int len) +int kfifo_from_user(struct kfifo *fifo, + const void __user *from, unsigned int len, unsigned *total) { + int ret; len = min(kfifo_avail(fifo), len); - len -= __kfifo_from_user_data(fifo, from, len, 0); + ret = __kfifo_from_user_data(fifo, from, len, 0, total); + if (ret) + return ret; __kfifo_add_in(fifo, len); - return len; + return 0; } EXPORT_SYMBOL(kfifo_from_user); @@ -339,17 +359,17 @@ unsigned int __kfifo_to_user_n(struct kfifo *fifo, void __user *to, unsigned int len, unsigned int reclen, unsigned int recsize) { - unsigned int ret; + unsigned int ret, total; if (kfifo_len(fifo) < reclen + recsize) return len; - ret = __kfifo_to_user_data(fifo, to, reclen, recsize); + ret = __kfifo_to_user_data(fifo, to, reclen, recsize, &total); if (likely(ret == 0)) __kfifo_add_out(fifo, reclen + recsize); - return ret; + return total; } EXPORT_SYMBOL(__kfifo_to_user_n); @@ -358,20 +378,22 @@ EXPORT_SYMBOL(__kfifo_to_user_n); * @fifo: the fifo to be used. * @to: where the data must be copied. * @len: the size of the destination buffer. + @ @lenout: pointer to output variable with copied data * * This function copies at most @len bytes from the FIFO into the - * @to buffer and returns the number of copied bytes. + * @to buffer and 0 or -EFAULT. * * Note that with only one concurrent reader and one concurrent * writer, you don't need extra locking to use these functions. */ -unsigned int kfifo_to_user(struct kfifo *fifo, - void __user *to, unsigned int len) +int kfifo_to_user(struct kfifo *fifo, + void __user *to, unsigned int len, unsigned *lenout) { + int ret; len = min(kfifo_len(fifo), len); - len -= __kfifo_to_user_data(fifo, to, len, 0); - __kfifo_add_out(fifo, len); - return len; + ret = __kfifo_to_user_data(fifo, to, len, 0, lenout); + __kfifo_add_out(fifo, *lenout); + return ret; } EXPORT_SYMBOL(kfifo_to_user); -- cgit v1.2.3-18-g5258 From a5b9e2c1063046421ce01dcf5ddd7ec12567f3e1 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Fri, 15 Jan 2010 17:01:16 -0800 Subject: kfifo: add kfifo_out_peek In some upcoming code it's useful to peek into a FIFO without permanentely removing data. This patch implements a new kfifo_out_peek() to do this. Signed-off-by: Andi Kleen Acked-by: Stefani Seibold Cc: Roland Dreier Cc: Dmitry Torokhov Cc: Andy Walls Cc: Vikram Dhillon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kfifo.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'kernel/kfifo.c') diff --git a/kernel/kfifo.c b/kernel/kfifo.c index b50bb622e8b..7384f120be8 100644 --- a/kernel/kfifo.c +++ b/kernel/kfifo.c @@ -302,6 +302,27 @@ unsigned int kfifo_out(struct kfifo *fifo, void *to, unsigned int len) } EXPORT_SYMBOL(kfifo_out); +/** + * kfifo_out_peek - copy some data from the FIFO, but do not remove it + * @fifo: the fifo to be used. + * @to: where the data must be copied. + * @len: the size of the destination buffer. + * @offset: offset into the fifo + * + * This function copies at most @len bytes at @offset from the FIFO + * into the @to buffer and returns the number of copied bytes. + * The data is not removed from the FIFO. + */ +unsigned int kfifo_out_peek(struct kfifo *fifo, void *to, unsigned int len, + unsigned offset) +{ + len = min(kfifo_len(fifo), len + offset); + + __kfifo_out_data(fifo, to, len, offset); + return len; +} +EXPORT_SYMBOL(kfifo_out_peek); + unsigned int __kfifo_out_generic(struct kfifo *fifo, void *to, unsigned int len, unsigned int recsize, unsigned int *total) -- cgit v1.2.3-18-g5258 From 5dab600e6a153ceb64832f608069e6c08185411a Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Fri, 15 Jan 2010 17:01:17 -0800 Subject: kfifo: document everywhere that size has to be power of two On my first try using them I missed that the fifos need to be power of two, resulting in a runtime bug. Document that requirement everywhere (and fix one grammar bug) Signed-off-by: Andi Kleen Acked-by: Stefani Seibold Cc: Roland Dreier Cc: Dmitry Torokhov Cc: Andy Walls Cc: Vikram Dhillon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kfifo.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/kfifo.c') diff --git a/kernel/kfifo.c b/kernel/kfifo.c index 7384f120be8..32c5c15d750 100644 --- a/kernel/kfifo.c +++ b/kernel/kfifo.c @@ -41,7 +41,7 @@ static void _kfifo_init(struct kfifo *fifo, void *buffer, * kfifo_init - initialize a FIFO using a preallocated buffer * @fifo: the fifo to assign the buffer * @buffer: the preallocated buffer to be used. - * @size: the size of the internal buffer, this have to be a power of 2. + * @size: the size of the internal buffer, this has to be a power of 2. * */ void kfifo_init(struct kfifo *fifo, void *buffer, unsigned int size) -- cgit v1.2.3-18-g5258