2003-03-20 20:01:00

by Randy.Dunlap

Subject: [PATCH] reduce stack usage in arch/sh/kernel/pci-sh7751

Hi,

This has already been done for arch/i386 and arch/x86_64 (same function
as is patched here). Please apply to 2.5.65.

Thanks,
--
~Randy


patch_name: sh-pci-dev-stack.patch
patch_version: 2003-03-20.11:47:35
author: Randy.Dunlap <[email protected]>
description: reduce stack usage in
arch/sh/kernel/pci-sh7751::pcibios_fixup_peer_bridges()
product: Linux
product_versions: 2.5.65
changelog: change pci_dev and pci_bus data to pointers & kmalloc() them;
same patch as already applied to i386 and x86_64;
maintainer: Niibe Yutaka: [email protected],
Kazumoto Kojima: [email protected]
(list: [email protected])
diffstat: =
arch/sh/kernel/pci-sh7751.c | 27 +++++++++++++++++++--------
1 files changed, 19 insertions(+), 8 deletions(-)


diff -Naur ./arch/sh/kernel/pci-sh7751.c%SHSTK ./arch/sh/kernel/pci-sh7751.c
--- ./arch/sh/kernel/pci-sh7751.c%SHSTK Mon Mar 17 13:44:19 2003
+++ ./arch/sh/kernel/pci-sh7751.c Thu Mar 20 11:46:08 2003
@@ -199,28 +199,39 @@
static void __init pcibios_fixup_peer_bridges(void)
{
int n;
- struct pci_bus bus;
- struct pci_dev dev;
+ struct pci_bus *bus;
+ struct pci_dev *dev;
u16 l;

if (pcibios_last_bus <= 0 || pcibios_last_bus >= 0xff)
return;
PCIDBG(2,"PCI: Peer bridge fixup\n");
+
+ bus = kmalloc(sizeof(*bus), GFP_ATOMIC);
+ dev = kmalloc(sizeof(*dev), GFP_ATOMIC);
+ if (!bus || !dev) {
+ printk(KERN_ERR "Out of memory in %s\n", __FUNCTION__);
+ goto exit;
+ }
+
for (n=0; n <= pcibios_last_bus; n++) {
if (pci_bus_exists(&pci_root_buses, n))
continue;
- bus.number = n;
- bus.ops = pci_root_ops;
- dev.bus = &bus;
- for(dev.devfn=0; dev.devfn<256; dev.devfn += 8)
- if (!pci_read_config_word(&dev, PCI_VENDOR_ID, &l) &&
+ bus->number = n;
+ bus->ops = pci_root_ops;
+ dev->bus = bus;
+ for(dev->devfn=0; dev->devfn<256; dev->devfn += 8)
+ if (!pci_read_config_word(dev, PCI_VENDOR_ID, &l) &&
l != 0x0000 && l != 0xffff) {
- PCIDBG(3,"Found device at %02x:%02x [%04x]\n", n, dev.devfn, l);
+ PCIDBG(3,"Found device at %02x:%02x [%04x]\n", n, dev->devfn, l);
printk(KERN_INFO "PCI: Discovered peer bus %02x\n", n);
pci_scan_bus(n, pci_root_ops, NULL);
break;
}
}
+exit:
+ kfree(dev);
+ kfree(bus);
}

2003-03-20 21:49:18

by Bob Miller

Subject: Re: [PATCH] reduce stack usage in arch/sh/kernel/pci-sh7751

On Thu, Mar 20, 2003 at 12:08:33PM -0800, Randy.Dunlap wrote:
> Hi,
>
> This has already been done for arch/i386 and arch/x86_64 (same function
> as is patched here). Please apply to 2.5.65.
>
> Thanks,
> --
> ~Randy
>
>
> patch_name: sh-pci-dev-stack.patch
> patch_version: 2003-03-20.11:47:35
> author: Randy.Dunlap <[email protected]>
> description: reduce stack usage in
> arch/sh/kernel/pci-sh7751::pcibios_fixup_peer_bridges()
> product: Linux
> product_versions: 2.5.65
> changelog: change pci_dev and pci_bus data to pointers & kmalloc() them;
> same patch as already applied to i386 and x86_64;
> maintainer: Niibe Yutaka: [email protected],
> Kazumoto Kojima: [email protected]
> (list: [email protected])
> diffstat: =
> arch/sh/kernel/pci-sh7751.c | 27 +++++++++++++++++++--------
> 1 files changed, 19 insertions(+), 8 deletions(-)
>
>
> diff -Naur ./arch/sh/kernel/pci-sh7751.c%SHSTK ./arch/sh/kernel/pci-sh7751.c
> --- ./arch/sh/kernel/pci-sh7751.c%SHSTK Mon Mar 17 13:44:19 2003
> +++ ./arch/sh/kernel/pci-sh7751.c Thu Mar 20 11:46:08 2003
> @@ -199,28 +199,39 @@
> static void __init pcibios_fixup_peer_bridges(void)
> {
> int n;
> - struct pci_bus bus;
> - struct pci_dev dev;
> + struct pci_bus *bus;
> + struct pci_dev *dev;
> u16 l;
>
> if (pcibios_last_bus <= 0 || pcibios_last_bus >= 0xff)
> return;
> PCIDBG(2,"PCI: Peer bridge fixup\n");
> +
> + bus = kmalloc(sizeof(*bus), GFP_ATOMIC);
> + dev = kmalloc(sizeof(*dev), GFP_ATOMIC);
> + if (!bus || !dev) {
> + printk(KERN_ERR "Out of memory in %s\n", __FUNCTION__);
> + goto exit;
> + }
> +
If the kmalloc() for bus succeeds but for dev fails this will leak the
memory given to bus.

--
Bob Miller Email: [email protected]
Open Source Development Lab Phone: 503.626.2455 Ext. 17

2003-03-20 21:56:53

by Bob Miller

Subject: Re: [PATCH] reduce stack usage in arch/sh/kernel/pci-sh7751

On Thu, Mar 20, 2003 at 01:59:11PM -0800, Bob Miller wrote:
> On Thu, Mar 20, 2003 at 12:08:33PM -0800, Randy.Dunlap wrote:
> > +
> > + bus = kmalloc(sizeof(*bus), GFP_ATOMIC);
> > + dev = kmalloc(sizeof(*dev), GFP_ATOMIC);
> > + if (!bus || !dev) {
> > + printk(KERN_ERR "Out of memory in %s\n", __FUNCTION__);
> > + goto exit;
> > + }
> > +
> If the kmalloc() for bus succeeds but for dev fails this will leak the
> memory given to bus.
>
That's a goto, not a return... Never mind.

--
Bob Miller Email: [email protected]
Open Source Development Lab Phone: 503.626.2455 Ext. 17