All of lore.kernel.org
 help / color / mirror / Atom feed
From: Qian Cai <cai@lca.pw>
To: bhelgaas@google.com
Cc: jamessewart@arista.com, logang@deltatee.com,
	linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	Qian Cai <cai@lca.pw>
Subject: [PATCH -next] pci: fix a -Wtype-limits compilation warning
Date: Wed, 18 Dec 2019 12:00:04 -0500	[thread overview]
Message-ID: <20191218170004.5297-1-cai@lca.pw> (raw)

The commit a7d06153eea2 ("PCI: Fix pci_add_dma_alias() bitmask size")
introduced a compilation warning and a potential infinite loop because
it is no longer possible to be self-terminated as u8 is always less than
256,

In file included from ./include/linux/kernel.h:12,
                 from ./include/asm-generic/bug.h:19,
                 from ./arch/x86/include/asm/bug.h:83,
                 from ./include/linux/bug.h:5,
                 from ./include/linux/jump_label.h:250,
                 from ./arch/x86/include/asm/string_64.h:6,
                 from ./arch/x86/include/asm/string.h:5,
                 from ./include/linux/string.h:20,
                 from ./include/linux/uuid.h:12,
                 from ./include/linux/mod_devicetable.h:13,
                 from ./include/linux/pci.h:27,
                 from drivers/pci/search.c:11:
drivers/pci/search.c: In function 'pci_for_each_dma_alias':
./include/linux/bitops.h:30:13: warning: comparison is always true due
to limited range of data type [-Wtype-limits]
       (bit) < (size);     \
             ^
drivers/pci/search.c:46:3: note: in expansion of macro 'for_each_set_bit'
   for_each_set_bit(devfn, pdev->dma_alias_mask, MAX_NR_DEVFNS) {

Fixed it by using u16 for "devfn" in this occasion.

Fixes: a7d06153eea2 ("PCI: Fix pci_add_dma_alias() bitmask size")
Signed-off-by: Qian Cai <cai@lca.pw>
---
 drivers/pci/search.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index 9e4dfae47252..42bc44d0e681 100644
--- a/drivers/pci/search.c
+++ b/drivers/pci/search.c
@@ -41,7 +41,7 @@ int pci_for_each_dma_alias(struct pci_dev *pdev,
 	 * DMA, iterate over that too.
 	 */
 	if (unlikely(pdev->dma_alias_mask)) {
-		u8 devfn;
+		u16 devfn;
 
 		for_each_set_bit(devfn, pdev->dma_alias_mask, MAX_NR_DEVFNS) {
 			ret = fn(pdev, PCI_DEVID(pdev->bus->number, devfn),
-- 
2.21.0 (Apple Git-122.2)


             reply	other threads:[~2019-12-18 17:00 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-18 17:00 Qian Cai [this message]
2019-12-18 17:22 ` [PATCH -next] pci: fix a -Wtype-limits compilation warning Logan Gunthorpe
2019-12-18 18:24 ` Bjorn Helgaas
2019-12-18 18:31   ` Logan Gunthorpe
2019-12-18 20:08   ` Qian Cai

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191218170004.5297-1-cai@lca.pw \
    --to=cai@lca.pw \
    --cc=bhelgaas@google.com \
    --cc=jamessewart@arista.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=logang@deltatee.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.