| Message ID | 20190410210532.4538-2-logang@deltatee.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | Fix disable_acs_redir parameter | expand |
On Wed, Apr 10, 2019 at 03:05:31PM -0600, Logan Gunthorpe wrote: > In most cases, kmalloc will not be available early in boot when > pci_setup() is called. Thus, the kstrdup call that was added to fix the > __initdata bug with the disable_acs_redir parameter usually returns > NULL. Thus the parameter is discarded and it does not take into effect. > > To fix this, we store the string that's in initdata until a initcall > function can allocate the memory appropriately. This way we > don't need any additional static memory. > > Fixes: d2fd6e81912a ("PCI: Fix __initdata issue with "pci=disable_acs_redir" parameter") > Signed-off-by: Logan Gunthorpe <logang@deltatee.com> > Cc: Bjorn Helgaas <bhelgaas@google.com> Applied to for-linus for v5.1, thanks, Logan! > --- > drivers/pci/pci.c | 19 +++++++++++++++++-- > 1 file changed, 17 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 7c1b362f599a..766f5779db92 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -6262,8 +6262,7 @@ static int __init pci_setup(char *str) > } else if (!strncmp(str, "pcie_scan_all", 13)) { > pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); > } else if (!strncmp(str, "disable_acs_redir=", 18)) { > - disable_acs_redir_param = > - kstrdup(str + 18, GFP_KERNEL); > + disable_acs_redir_param = str + 18; > } else { > printk(KERN_ERR "PCI: Unknown option `%s'\n", > str); > @@ -6274,3 +6273,19 @@ static int __init pci_setup(char *str) > return 0; > } > early_param("pci", pci_setup); > + > +/* > + * 'disable_acs_redir_param' is initialized in pci_setup(), above, to point > + * to data in the __initdata section which will be freed after the init > + * sequence is complete. We can't allocate memory in pci_setup() because some > + * architectures do not have any memory allocation service available during > + * an early_param() call. So we allocate memory and copy the variable here > + * before the init section is freed. > + */ > +static int __init pci_realloc_setup_params(void) > +{ > + disable_acs_redir_param = kstrdup(disable_acs_redir_param, GFP_KERNEL); > + > + return 0; > +} > +pure_initcall(pci_realloc_setup_params); > -- > 2.20.1 >
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 7c1b362f599a..766f5779db92 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -6262,8 +6262,7 @@ static int __init pci_setup(char *str) } else if (!strncmp(str, "pcie_scan_all", 13)) { pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); } else if (!strncmp(str, "disable_acs_redir=", 18)) { - disable_acs_redir_param = - kstrdup(str + 18, GFP_KERNEL); + disable_acs_redir_param = str + 18; } else { printk(KERN_ERR "PCI: Unknown option `%s'\n", str); @@ -6274,3 +6273,19 @@ static int __init pci_setup(char *str) return 0; } early_param("pci", pci_setup); + +/* + * 'disable_acs_redir_param' is initialized in pci_setup(), above, to point + * to data in the __initdata section which will be freed after the init + * sequence is complete. We can't allocate memory in pci_setup() because some + * architectures do not have any memory allocation service available during + * an early_param() call. So we allocate memory and copy the variable here + * before the init section is freed. + */ +static int __init pci_realloc_setup_params(void) +{ + disable_acs_redir_param = kstrdup(disable_acs_redir_param, GFP_KERNEL); + + return 0; +} +pure_initcall(pci_realloc_setup_params);
In most cases, kmalloc will not be available early in boot when pci_setup() is called. Thus, the kstrdup call that was added to fix the __initdata bug with the disable_acs_redir parameter usually returns NULL. Thus the parameter is discarded and it does not take into effect. To fix this, we store the string that's in initdata until a initcall function can allocate the memory appropriately. This way we don't need any additional static memory. Fixes: d2fd6e81912a ("PCI: Fix __initdata issue with "pci=disable_acs_redir" parameter") Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Bjorn Helgaas <bhelgaas@google.com> --- drivers/pci/pci.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)