| Message ID | 20180428001526.22475-1-mcgrof@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Apr 27, 2018 at 05:15:26PM -0700, Luis R. Rodriguez wrote: > Some architectures do not define PAGE_KERNEL_RO, best we can do > for them is to provide a fallback onto PAGE_KERNEL. Remove the > hack from the firmware loader and move it onto the asm-generic > header, and document while at it the affected architectures > which do not have a PAGE_KERNEL_RO: > > o alpha > o ia64 > o m68k > o mips > o sparc64 > o sparc > > Blessed-by: 0-day New tag? :)
Hi Luis, On Sat, Apr 28, 2018 at 2:15 AM, Luis R. Rodriguez <mcgrof@kernel.org> wrote: > Some architectures do not define PAGE_KERNEL_RO, best we can do > for them is to provide a fallback onto PAGE_KERNEL. Remove the > hack from the firmware loader and move it onto the asm-generic > header, and document while at it the affected architectures > which do not have a PAGE_KERNEL_RO: > > o alpha > o ia64 > o m68k > o mips > o sparc64 > o sparc > > Blessed-by: 0-day > Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> I believe the "best we can do" is to add the missing definitions for the architectures where the hardware does support it? Gr{oetje,eeting}s, Geert
On Wed, May 02, 2018 at 12:08:57PM +0200, Geert Uytterhoeven wrote: > Hi Luis, > > On Sat, Apr 28, 2018 at 2:15 AM, Luis R. Rodriguez <mcgrof@kernel.org> wrote: > > Some architectures do not define PAGE_KERNEL_RO, best we can do > > for them is to provide a fallback onto PAGE_KERNEL. Remove the > > hack from the firmware loader and move it onto the asm-generic > > header, and document while at it the affected architectures > > which do not have a PAGE_KERNEL_RO: > > > > o alpha > > o ia64 > > o m68k > > o mips > > o sparc64 > > o sparc > > > > Blessed-by: 0-day > > Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> > > I believe the "best we can do" is to add the missing definitions for the > architectures where the hardware does support it? True, but we cannot wait for every architecture to implement a feature to then such generics upstream, specially when we have common places which use that. Matthew did send a patch to add ia64 support for PAGE_KERNEL_RO, so I'll respin the patch to add that and also move the other define he suggested. At least we'd now have a list of documented archs which need further work too. Luis
On Wed, May 02, 2018 at 03:11:13PM +0000, Luis R. Rodriguez wrote: > On Wed, May 02, 2018 at 12:08:57PM +0200, Geert Uytterhoeven wrote: > > Hi Luis, > > > > On Sat, Apr 28, 2018 at 2:15 AM, Luis R. Rodriguez <mcgrof@kernel.org> wrote: > > > Some architectures do not define PAGE_KERNEL_RO, best we can do > > > for them is to provide a fallback onto PAGE_KERNEL. Remove the > > > hack from the firmware loader and move it onto the asm-generic > > > header, and document while at it the affected architectures > > > which do not have a PAGE_KERNEL_RO: > > > > > > o alpha > > > o ia64 > > > o m68k > > > o mips > > > o sparc64 > > > o sparc > > > > > > Blessed-by: 0-day > > > Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> > > > > I believe the "best we can do" is to add the missing definitions for the > > architectures where the hardware does support it? > > True, but we cannot wait for every architecture to implement a feature to then > such generics upstream, Come to think of it your point was the wording. I changed it to not be as misleading. Luis
diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c index 31b5015b59fe..90f36be9e5ca 100644 --- a/drivers/base/firmware_loader/fallback.c +++ b/drivers/base/firmware_loader/fallback.c @@ -219,11 +219,6 @@ static ssize_t firmware_loading_show(struct device *dev, return sprintf(buf, "%d\n", loading); } -/* Some architectures don't have PAGE_KERNEL_RO */ -#ifndef PAGE_KERNEL_RO -#define PAGE_KERNEL_RO PAGE_KERNEL -#endif - /* one pages buffer should be mapped/unmapped only once */ static int map_fw_priv_pages(struct fw_priv *fw_priv) { diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index f59639afaa39..da47fe81df51 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -1083,6 +1083,21 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, static inline void init_espfix_bsp(void) { } #endif +/* + * Some architectures don't have PAGE_KERNEL_RO. This is the best + * we can do for them buggers for now. Currently known to not have it: + * + * o alpha + * o ia64 + * o m68k + * o mips + * o sparc64 + * o sparc + */ +#ifndef PAGE_KERNEL_RO +#define PAGE_KERNEL_RO PAGE_KERNEL +#endif + #endif /* !__ASSEMBLY__ */ #ifndef io_remap_pfn_range
Some architectures do not define PAGE_KERNEL_RO, best we can do for them is to provide a fallback onto PAGE_KERNEL. Remove the hack from the firmware loader and move it onto the asm-generic header, and document while at it the affected architectures which do not have a PAGE_KERNEL_RO: o alpha o ia64 o m68k o mips o sparc64 o sparc Blessed-by: 0-day Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> --- drivers/base/firmware_loader/fallback.c | 5 ----- include/asm-generic/pgtable.h | 15 +++++++++++++++ 2 files changed, 15 insertions(+), 5 deletions(-)