From 0a484a3af905a256cbdd7079defceac62b39e8fa Mon Sep 17 00:00:00 2001 From: "Antonino A. Daplas" Date: Mon, 9 Jan 2006 20:53:37 -0800 Subject: [PATCH] [PATCH] fbdev: Fix return code of fb_read and fb_write Make fb_read() and fb_write() return 0 (EOF) instead of -ENOSPC if reading at or past the end of the framebuffer. This fixes user space apps hanging if info->fix.smem_len == 0. Whitespace changes. Signed-off-by: Antonino Daplas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/video/fbmem.c | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c index 10dfdf035264..83e259413115 100644 --- a/drivers/video/fbmem.c +++ b/drivers/video/fbmem.c @@ -589,17 +589,19 @@ fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) return info->fbops->fb_read(file, buf, count, ppos); total_size = info->screen_size; + if (total_size == 0) total_size = info->fix.smem_len; if (p >= total_size) - return 0; + return 0; + if (count >= total_size) - count = total_size; + count = total_size; + if (count + p > total_size) count = total_size - p; - cnt = 0; buffer = kmalloc((count > PAGE_SIZE) ? PAGE_SIZE : count, GFP_KERNEL); if (!buffer) @@ -636,6 +638,7 @@ fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) } kfree(buffer); + return (err) ? err : cnt; } @@ -648,7 +651,7 @@ fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) struct fb_info *info = registered_fb[fbidx]; u32 *buffer, *src; u32 __iomem *dst; - int c, i, cnt = 0, err; + int c, i, cnt = 0, err = 0; unsigned long total_size; if (!info || !info->screen_base) @@ -661,19 +664,19 @@ fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) return info->fbops->fb_write(file, buf, count, ppos); total_size = info->screen_size; + if (total_size == 0) total_size = info->fix.smem_len; if (p > total_size) - return -ENOSPC; + return 0; + if (count >= total_size) - count = total_size; - err = 0; - if (count + p > total_size) { - count = total_size - p; - err = -ENOSPC; - } - cnt = 0; + count = total_size; + + if (count + p > total_size) + count = total_size - p; + buffer = kmalloc((count > PAGE_SIZE) ? PAGE_SIZE : count, GFP_KERNEL); if (!buffer) @@ -687,12 +690,15 @@ fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) while (count) { c = (count > PAGE_SIZE) ? PAGE_SIZE : count; src = buffer; + if (copy_from_user(src, buf, c)) { err = -EFAULT; break; } + for (i = c >> 2; i--; ) fb_writel(*src++, dst++); + if (c & 3) { u8 *src8 = (u8 *) src; u8 __iomem *dst8 = (u8 __iomem *) dst; @@ -702,11 +708,13 @@ fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) dst = (u32 __iomem *) dst8; } + *ppos += c; buf += c; cnt += c; count -= c; } + kfree(buffer); return (err) ? err : cnt; -- 2.39.5