From 498d319bb512992ef0784c278fa03679f2f5649d Mon Sep 17 00:00:00 2001 From: Stefani Seibold Date: Thu, 14 Nov 2013 14:32:17 -0800 Subject: [PATCH] kfifo API type safety This patch enhances the type safety for the kfifo API. It is now safe to put const data into a non const FIFO and the API will now generate a compiler warning when reading from the fifo where the destination address is pointing to a const variable. As a side effect the kfifo_put() does now expect the value of an element instead a pointer to the element. This was suggested Russell King. It make the handling of the kfifo_put easier since there is no need to create a helper variable for getting the address of a pointer or to pass integers of different sizes. IMHO the API break is okay, since there are currently only six users of kfifo_put(). The code is also cleaner by kicking out the "if (0)" expressions. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Stefani Seibold Cc: Russell King Cc: Hauke Mehrtens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/gpu/drm/drm_flip_work.c | 2 +- drivers/iio/industrialio-event.c | 2 +- drivers/net/wireless/rt2x00/rt2800mmio.c | 2 +- drivers/net/wireless/rt2x00/rt2800usb.c | 2 +- drivers/pci/pcie/aer/aerdrv_core.c | 2 +- include/linux/kfifo.h | 47 +++++++----------------- mm/memory-failure.c | 2 +- samples/kfifo/bytestream-example.c | 4 +- samples/kfifo/dma-example.c | 2 +- samples/kfifo/inttype-example.c | 4 +- 10 files changed, 25 insertions(+), 44 deletions(-) diff --git a/drivers/gpu/drm/drm_flip_work.c b/drivers/gpu/drm/drm_flip_work.c index e788882d9021..f9c7fa3d0012 100644 --- a/drivers/gpu/drm/drm_flip_work.c +++ b/drivers/gpu/drm/drm_flip_work.c @@ -34,7 +34,7 @@ */ void drm_flip_work_queue(struct drm_flip_work *work, void *val) { - if (kfifo_put(&work->fifo, (const void **)&val)) { + if (kfifo_put(&work->fifo, val)) { atomic_inc(&work->pending); } else { DRM_ERROR("%s fifo full!\n", work->name); diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c index dac15b9f9df8..c10eab64bc05 100644 --- a/drivers/iio/industrialio-event.c +++ b/drivers/iio/industrialio-event.c @@ -56,7 +56,7 @@ int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp) ev.id = ev_code; ev.timestamp = timestamp; - copied = kfifo_put(&ev_int->det_events, &ev); + copied = kfifo_put(&ev_int->det_events, ev); if (copied != 0) wake_up_locked_poll(&ev_int->wait, POLLIN); } diff --git a/drivers/net/wireless/rt2x00/rt2800mmio.c b/drivers/net/wireless/rt2x00/rt2800mmio.c index ae152280e071..a8cc736b5063 100644 --- a/drivers/net/wireless/rt2x00/rt2800mmio.c +++ b/drivers/net/wireless/rt2x00/rt2800mmio.c @@ -446,7 +446,7 @@ static void rt2800mmio_txstatus_interrupt(struct rt2x00_dev *rt2x00dev) if (!rt2x00_get_field32(status, TX_STA_FIFO_VALID)) break; - if (!kfifo_put(&rt2x00dev->txstatus_fifo, &status)) { + if (!kfifo_put(&rt2x00dev->txstatus_fifo, status)) { rt2x00_warn(rt2x00dev, "TX status FIFO overrun, drop tx status report\n"); break; } diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c index 997df03a0c2e..a81ceb61d746 100644 --- a/drivers/net/wireless/rt2x00/rt2800usb.c +++ b/drivers/net/wireless/rt2x00/rt2800usb.c @@ -164,7 +164,7 @@ static bool rt2800usb_tx_sta_fifo_read_completed(struct rt2x00_dev *rt2x00dev, valid = rt2x00_get_field32(tx_status, TX_STA_FIFO_VALID); if (valid) { - if (!kfifo_put(&rt2x00dev->txstatus_fifo, &tx_status)) + if (!kfifo_put(&rt2x00dev->txstatus_fifo, tx_status)) rt2x00_warn(rt2x00dev, "TX status FIFO overrun\n"); queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work); diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c index 85ca36f2136d..6b3a958e1be6 100644 --- a/drivers/pci/pcie/aer/aerdrv_core.c +++ b/drivers/pci/pcie/aer/aerdrv_core.c @@ -574,7 +574,7 @@ void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn, }; spin_lock_irqsave(&aer_recover_ring_lock, flags); - if (kfifo_put(&aer_recover_ring, &entry)) + if (kfifo_put(&aer_recover_ring, entry)) schedule_work(&aer_recover_work); else pr_err("AER recover: Buffer overflow when recovering AER for %04x:%02x:%02x:%x\n", diff --git a/include/linux/kfifo.h b/include/linux/kfifo.h index 10308c6a3d1c..552d51efb429 100644 --- a/include/linux/kfifo.h +++ b/include/linux/kfifo.h @@ -1,7 +1,7 @@ /* * A generic kernel FIFO implementation * - * Copyright (C) 2009/2010 Stefani Seibold + * Copyright (C) 2013 Stefani Seibold * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -67,9 +67,10 @@ struct __kfifo { union { \ struct __kfifo kfifo; \ datatype *type; \ + const datatype *const_type; \ char (*rectype)[recsize]; \ ptrtype *ptr; \ - const ptrtype *ptr_const; \ + ptrtype const *ptr_const; \ } #define __STRUCT_KFIFO(type, size, recsize, ptrtype) \ @@ -386,16 +387,12 @@ __kfifo_int_must_check_helper( \ #define kfifo_put(fifo, val) \ ({ \ typeof((fifo) + 1) __tmp = (fifo); \ - typeof((val) + 1) __val = (val); \ + typeof(*__tmp->const_type) __val = (val); \ unsigned int __ret; \ - const size_t __recsize = sizeof(*__tmp->rectype); \ + size_t __recsize = sizeof(*__tmp->rectype); \ struct __kfifo *__kfifo = &__tmp->kfifo; \ - if (0) { \ - typeof(__tmp->ptr_const) __dummy __attribute__ ((unused)); \ - __dummy = (typeof(__val))NULL; \ - } \ if (__recsize) \ - __ret = __kfifo_in_r(__kfifo, __val, sizeof(*__val), \ + __ret = __kfifo_in_r(__kfifo, &__val, sizeof(__val), \ __recsize); \ else { \ __ret = !kfifo_is_full(__tmp); \ @@ -404,7 +401,7 @@ __kfifo_int_must_check_helper( \ ((typeof(__tmp->type))__kfifo->data) : \ (__tmp->buf) \ )[__kfifo->in & __tmp->kfifo.mask] = \ - *(typeof(__tmp->type))__val; \ + (typeof(*__tmp->type))__val; \ smp_wmb(); \ __kfifo->in++; \ } \ @@ -415,7 +412,7 @@ __kfifo_int_must_check_helper( \ /** * kfifo_get - get data from the fifo * @fifo: address of the fifo to be used - * @val: the var where to store the data to be added + * @val: address where to store the data * * This macro reads the data from the fifo. * It returns 0 if the fifo was empty. Otherwise it returns the number @@ -428,12 +425,10 @@ __kfifo_int_must_check_helper( \ __kfifo_uint_must_check_helper( \ ({ \ typeof((fifo) + 1) __tmp = (fifo); \ - typeof((val) + 1) __val = (val); \ + typeof(__tmp->ptr) __val = (val); \ unsigned int __ret; \ const size_t __recsize = sizeof(*__tmp->rectype); \ struct __kfifo *__kfifo = &__tmp->kfifo; \ - if (0) \ - __val = (typeof(__tmp->ptr))0; \ if (__recsize) \ __ret = __kfifo_out_r(__kfifo, __val, sizeof(*__val), \ __recsize); \ @@ -456,7 +451,7 @@ __kfifo_uint_must_check_helper( \ /** * kfifo_peek - get data from the fifo without removing * @fifo: address of the fifo to be used - * @val: the var where to store the data to be added + * @val: address where to store the data * * This reads the data from the fifo without removing it from the fifo. * It returns 0 if the fifo was empty. Otherwise it returns the number @@ -469,12 +464,10 @@ __kfifo_uint_must_check_helper( \ __kfifo_uint_must_check_helper( \ ({ \ typeof((fifo) + 1) __tmp = (fifo); \ - typeof((val) + 1) __val = (val); \ + typeof(__tmp->ptr) __val = (val); \ unsigned int __ret; \ const size_t __recsize = sizeof(*__tmp->rectype); \ struct __kfifo *__kfifo = &__tmp->kfifo; \ - if (0) \ - __val = (typeof(__tmp->ptr))NULL; \ if (__recsize) \ __ret = __kfifo_out_peek_r(__kfifo, __val, sizeof(*__val), \ __recsize); \ @@ -508,14 +501,10 @@ __kfifo_uint_must_check_helper( \ #define kfifo_in(fifo, buf, n) \ ({ \ typeof((fifo) + 1) __tmp = (fifo); \ - typeof((buf) + 1) __buf = (buf); \ + typeof(__tmp->ptr_const) __buf = (buf); \ unsigned long __n = (n); \ const size_t __recsize = sizeof(*__tmp->rectype); \ struct __kfifo *__kfifo = &__tmp->kfifo; \ - if (0) { \ - typeof(__tmp->ptr_const) __dummy __attribute__ ((unused)); \ - __dummy = (typeof(__buf))NULL; \ - } \ (__recsize) ?\ __kfifo_in_r(__kfifo, __buf, __n, __recsize) : \ __kfifo_in(__kfifo, __buf, __n); \ @@ -561,14 +550,10 @@ __kfifo_uint_must_check_helper( \ __kfifo_uint_must_check_helper( \ ({ \ typeof((fifo) + 1) __tmp = (fifo); \ - typeof((buf) + 1) __buf = (buf); \ + typeof(__tmp->ptr) __buf = (buf); \ unsigned long __n = (n); \ const size_t __recsize = sizeof(*__tmp->rectype); \ struct __kfifo *__kfifo = &__tmp->kfifo; \ - if (0) { \ - typeof(__tmp->ptr) __dummy = NULL; \ - __buf = __dummy; \ - } \ (__recsize) ?\ __kfifo_out_r(__kfifo, __buf, __n, __recsize) : \ __kfifo_out(__kfifo, __buf, __n); \ @@ -773,14 +758,10 @@ __kfifo_uint_must_check_helper( \ __kfifo_uint_must_check_helper( \ ({ \ typeof((fifo) + 1) __tmp = (fifo); \ - typeof((buf) + 1) __buf = (buf); \ + typeof(__tmp->ptr) __buf = (buf); \ unsigned long __n = (n); \ const size_t __recsize = sizeof(*__tmp->rectype); \ struct __kfifo *__kfifo = &__tmp->kfifo; \ - if (0) { \ - typeof(__tmp->ptr) __dummy __attribute__ ((unused)) = NULL; \ - __buf = __dummy; \ - } \ (__recsize) ? \ __kfifo_out_peek_r(__kfifo, __buf, __n, __recsize) : \ __kfifo_out_peek(__kfifo, __buf, __n); \ diff --git a/mm/memory-failure.c b/mm/memory-failure.c index f9d78ec7831f..b7c171602ba1 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1269,7 +1269,7 @@ void memory_failure_queue(unsigned long pfn, int trapno, int flags) mf_cpu = &get_cpu_var(memory_failure_cpu); spin_lock_irqsave(&mf_cpu->lock, proc_flags); - if (kfifo_put(&mf_cpu->fifo, &entry)) + if (kfifo_put(&mf_cpu->fifo, entry)) schedule_work_on(smp_processor_id(), &mf_cpu->work); else pr_err("Memory failure: buffer overflow when queuing memory failure at %#lx\n", diff --git a/samples/kfifo/bytestream-example.c b/samples/kfifo/bytestream-example.c index cfe40addda76..2fca916d9edf 100644 --- a/samples/kfifo/bytestream-example.c +++ b/samples/kfifo/bytestream-example.c @@ -64,7 +64,7 @@ static int __init testfunc(void) /* put values into the fifo */ for (i = 0; i != 10; i++) - kfifo_put(&test, &i); + kfifo_put(&test, i); /* show the number of used elements */ printk(KERN_INFO "fifo len: %u\n", kfifo_len(&test)); @@ -85,7 +85,7 @@ static int __init testfunc(void) kfifo_skip(&test); /* put values into the fifo until is full */ - for (i = 20; kfifo_put(&test, &i); i++) + for (i = 20; kfifo_put(&test, i); i++) ; printk(KERN_INFO "queue len: %u\n", kfifo_len(&test)); diff --git a/samples/kfifo/dma-example.c b/samples/kfifo/dma-example.c index 06473791c08a..aa243db93f01 100644 --- a/samples/kfifo/dma-example.c +++ b/samples/kfifo/dma-example.c @@ -39,7 +39,7 @@ static int __init example_init(void) kfifo_in(&fifo, "test", 4); for (i = 0; i != 9; i++) - kfifo_put(&fifo, &i); + kfifo_put(&fifo, i); /* kick away first byte */ kfifo_skip(&fifo); diff --git a/samples/kfifo/inttype-example.c b/samples/kfifo/inttype-example.c index 6f8e79e76c9e..8dc3c2e7105a 100644 --- a/samples/kfifo/inttype-example.c +++ b/samples/kfifo/inttype-example.c @@ -61,7 +61,7 @@ static int __init testfunc(void) /* put values into the fifo */ for (i = 0; i != 10; i++) - kfifo_put(&test, &i); + kfifo_put(&test, i); /* show the number of used elements */ printk(KERN_INFO "fifo len: %u\n", kfifo_len(&test)); @@ -78,7 +78,7 @@ static int __init testfunc(void) kfifo_skip(&test); /* put values into the fifo until is full */ - for (i = 20; kfifo_put(&test, &i); i++) + for (i = 20; kfifo_put(&test, i); i++) ; printk(KERN_INFO "queue len: %u\n", kfifo_len(&test)); -- 2.34.1