From: Bjorn Helgaas Date: Thu, 31 Jul 2008 07:07:27 +0000 (-0700) Subject: PNP: fix formatting of dbg_pnp_show_resources() output X-Git-Tag: v2.6.27-rc2~88 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ea44c1d60df3640bd956a67c392865c44fe9bc45;p=linux-2.6 PNP: fix formatting of dbg_pnp_show_resources() output Each resource should be printed on its own line, so start snprintf'ing at the beginning of the buffer every time through the loop. Also, use scnprintf() rather than snprintf() when building up the buffer to print. scnprintf() returns the number of characters actually written into the buffer (not including the trailing NULL). snprintf() returns the number of characters that *would be* written, assuming everything would fit in the buffer. That's nice if we want to resize the buffer to make sure everything fits, but in this case, I just want to keep from overflowing the buffer, and it's OK if the output is truncated. Using snprintf() meant that my "len" could grow to be more than the the buffer size, which makes "sizeof(buf) - len" negative, which causes this alarming WARN_ON: http://marc.info/?l=linux-kernel&m=121736480005656&w=2 More useful snprintf/scnprintf discussion: http://lwn.net/Articles/69419/ Signed-off-by: Bjorn Helgaas Reported-by: Pete Clements Cc: Rene Herman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/pnp/support.c b/drivers/pnp/support.c index bbf78ef4ba..b42df16207 100644 --- a/drivers/pnp/support.c +++ b/drivers/pnp/support.c @@ -77,7 +77,7 @@ void dbg_pnp_show_resources(struct pnp_dev *dev, char *desc) { #ifdef DEBUG char buf[128]; - int len = 0; + int len; struct pnp_resource *pnp_res; struct resource *res; @@ -89,9 +89,10 @@ void dbg_pnp_show_resources(struct pnp_dev *dev, char *desc) dev_dbg(&dev->dev, "%s: current resources:\n", desc); list_for_each_entry(pnp_res, &dev->resources, list) { res = &pnp_res->res; + len = 0; - len += snprintf(buf + len, sizeof(buf) - len, " %-3s ", - pnp_resource_type_name(res)); + len += scnprintf(buf + len, sizeof(buf) - len, " %-3s ", + pnp_resource_type_name(res)); if (res->flags & IORESOURCE_DISABLED) { dev_dbg(&dev->dev, "%sdisabled\n", buf); @@ -101,18 +102,18 @@ void dbg_pnp_show_resources(struct pnp_dev *dev, char *desc) switch (pnp_resource_type(res)) { case IORESOURCE_IO: case IORESOURCE_MEM: - len += snprintf(buf + len, sizeof(buf) - len, - "%#llx-%#llx flags %#lx", - (unsigned long long) res->start, - (unsigned long long) res->end, - res->flags); + len += scnprintf(buf + len, sizeof(buf) - len, + "%#llx-%#llx flags %#lx", + (unsigned long long) res->start, + (unsigned long long) res->end, + res->flags); break; case IORESOURCE_IRQ: case IORESOURCE_DMA: - len += snprintf(buf + len, sizeof(buf) - len, - "%lld flags %#lx", - (unsigned long long) res->start, - res->flags); + len += scnprintf(buf + len, sizeof(buf) - len, + "%lld flags %#lx", + (unsigned long long) res->start, + res->flags); break; } dev_dbg(&dev->dev, "%s\n", buf); @@ -144,66 +145,67 @@ void dbg_pnp_show_option(struct pnp_dev *dev, struct pnp_option *option) struct pnp_dma *dma; if (pnp_option_is_dependent(option)) - len += snprintf(buf + len, sizeof(buf) - len, - " dependent set %d (%s) ", - pnp_option_set(option), - pnp_option_priority_name(option)); + len += scnprintf(buf + len, sizeof(buf) - len, + " dependent set %d (%s) ", + pnp_option_set(option), + pnp_option_priority_name(option)); else - len += snprintf(buf + len, sizeof(buf) - len, " independent "); + len += scnprintf(buf + len, sizeof(buf) - len, + " independent "); switch (option->type) { case IORESOURCE_IO: port = &option->u.port; - len += snprintf(buf + len, sizeof(buf) - len, "io min %#llx " - "max %#llx align %lld size %lld flags %#x", - (unsigned long long) port->min, - (unsigned long long) port->max, - (unsigned long long) port->align, - (unsigned long long) port->size, port->flags); + len += scnprintf(buf + len, sizeof(buf) - len, "io min %#llx " + "max %#llx align %lld size %lld flags %#x", + (unsigned long long) port->min, + (unsigned long long) port->max, + (unsigned long long) port->align, + (unsigned long long) port->size, port->flags); break; case IORESOURCE_MEM: mem = &option->u.mem; - len += snprintf(buf + len, sizeof(buf) - len, "mem min %#llx " - "max %#llx align %lld size %lld flags %#x", - (unsigned long long) mem->min, - (unsigned long long) mem->max, - (unsigned long long) mem->align, - (unsigned long long) mem->size, mem->flags); + len += scnprintf(buf + len, sizeof(buf) - len, "mem min %#llx " + "max %#llx align %lld size %lld flags %#x", + (unsigned long long) mem->min, + (unsigned long long) mem->max, + (unsigned long long) mem->align, + (unsigned long long) mem->size, mem->flags); break; case IORESOURCE_IRQ: irq = &option->u.irq; - len += snprintf(buf + len, sizeof(buf) - len, "irq"); + len += scnprintf(buf + len, sizeof(buf) - len, "irq"); if (bitmap_empty(irq->map.bits, PNP_IRQ_NR)) - len += snprintf(buf + len, sizeof(buf) - len, - " "); + len += scnprintf(buf + len, sizeof(buf) - len, + " "); else { for (i = 0; i < PNP_IRQ_NR; i++) if (test_bit(i, irq->map.bits)) - len += snprintf(buf + len, - sizeof(buf) - len, - " %d", i); + len += scnprintf(buf + len, + sizeof(buf) - len, + " %d", i); } - len += snprintf(buf + len, sizeof(buf) - len, " flags %#x", - irq->flags); + len += scnprintf(buf + len, sizeof(buf) - len, " flags %#x", + irq->flags); if (irq->flags & IORESOURCE_IRQ_OPTIONAL) - len += snprintf(buf + len, sizeof(buf) - len, - " (optional)"); + len += scnprintf(buf + len, sizeof(buf) - len, + " (optional)"); break; case IORESOURCE_DMA: dma = &option->u.dma; - len += snprintf(buf + len, sizeof(buf) - len, "dma"); + len += scnprintf(buf + len, sizeof(buf) - len, "dma"); if (!dma->map) - len += snprintf(buf + len, sizeof(buf) - len, - " "); + len += scnprintf(buf + len, sizeof(buf) - len, + " "); else { for (i = 0; i < 8; i++) if (dma->map & (1 << i)) - len += snprintf(buf + len, - sizeof(buf) - len, - " %d", i); + len += scnprintf(buf + len, + sizeof(buf) - len, + " %d", i); } - len += snprintf(buf + len, sizeof(buf) - len, " (bitmask %#x) " - "flags %#x", dma->map, dma->flags); + len += scnprintf(buf + len, sizeof(buf) - len, " (bitmask %#x) " + "flags %#x", dma->map, dma->flags); break; } dev_dbg(&dev->dev, "%s\n", buf);