| Message ID | 20170530091446.1000183-1-arnd@arndb.de |
|---|---|
| State | New |
| Headers | show |
On 05/30/17 at 11:14am, Arnd Bergmann wrote: > The decompressor has its own implementation of the string functions, > but has to include the right header to get those, while implicitly > including linux/string.h may result in a link error: > > arch/x86/boot/compressed/kaslr.o: In function `choose_random_location': > kaslr.c:(.text+0xf51): undefined reference to `_mmx_memcpy' > > This has appeared now as kaslr started using memcpy. Other files in the > decompressor already do the same thing. > > Fixes: d52e7d5a952c ("x86/KASLR: Parse all 'memmap=' boot option entries") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Thanks for this fix, Arnd! The linking error didn't happen when I tested the patch of d52e7d5a952c. Could you tell in what condition it will be triggered? Not sure if I should wait for this fix being merged and do a back porting, or can defer it if it's not risky. Thanks Baoquan > --- > arch/x86/boot/compressed/kaslr.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c > index e0eba12bffe7..fe318b44f7b8 100644 > --- a/arch/x86/boot/compressed/kaslr.c > +++ b/arch/x86/boot/compressed/kaslr.c > @@ -30,6 +30,7 @@ > > #include "misc.h" > #include "error.h" > +#include "../string.h" > > #include <generated/compile.h> > #include <linux/module.h> > -- > 2.9.0 >
On Tue, May 30, 2017 at 3:56 PM, Baoquan He <bhe@redhat.com> wrote: > On 05/30/17 at 11:14am, Arnd Bergmann wrote: >> The decompressor has its own implementation of the string functions, >> but has to include the right header to get those, while implicitly >> including linux/string.h may result in a link error: >> >> arch/x86/boot/compressed/kaslr.o: In function `choose_random_location': >> kaslr.c:(.text+0xf51): undefined reference to `_mmx_memcpy' >> >> This has appeared now as kaslr started using memcpy. Other files in the >> decompressor already do the same thing. >> >> Fixes: d52e7d5a952c ("x86/KASLR: Parse all 'memmap=' boot option entries") >> Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > Thanks for this fix, Arnd! > > The linking error didn't happen when I tested the patch of d52e7d5a952c. > Could you tell in what condition it will be triggered? Not sure if I > should wait for this fix being merged and do a back porting, or can > defer it if it's not risky. It only happens on 32-bit kernels with CONFIG_X86_USE_3DNOW, maybe there are additional requirements. Arnd
On 05/30/17 at 04:24pm, Arnd Bergmann wrote: > On Tue, May 30, 2017 at 3:56 PM, Baoquan He <bhe@redhat.com> wrote: > > On 05/30/17 at 11:14am, Arnd Bergmann wrote: > >> The decompressor has its own implementation of the string functions, > >> but has to include the right header to get those, while implicitly > >> including linux/string.h may result in a link error: > >> > >> arch/x86/boot/compressed/kaslr.o: In function `choose_random_location': > >> kaslr.c:(.text+0xf51): undefined reference to `_mmx_memcpy' > >> > >> This has appeared now as kaslr started using memcpy. Other files in the > >> decompressor already do the same thing. > >> > >> Fixes: d52e7d5a952c ("x86/KASLR: Parse all 'memmap=' boot option entries") > >> Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > > > Thanks for this fix, Arnd! > > > > The linking error didn't happen when I tested the patch of d52e7d5a952c. > > Could you tell in what condition it will be triggered? Not sure if I > > should wait for this fix being merged and do a back porting, or can > > defer it if it's not risky. > > It only happens on 32-bit kernels with CONFIG_X86_USE_3DNOW, maybe > there are additional requirements. Checked code again, in commit d52e7d5a952c "#include "../boot.h" is removed. Not sure if that removal caused the 32-bit kernel link error. While I didn't see boot/string.h is included into the boot/boot.h.
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index e0eba12bffe7..fe318b44f7b8 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -30,6 +30,7 @@ #include "misc.h" #include "error.h" +#include "../string.h" #include <generated/compile.h> #include <linux/module.h>
The decompressor has its own implementation of the string functions, but has to include the right header to get those, while implicitly including linux/string.h may result in a link error: arch/x86/boot/compressed/kaslr.o: In function `choose_random_location': kaslr.c:(.text+0xf51): undefined reference to `_mmx_memcpy' This has appeared now as kaslr started using memcpy. Other files in the decompressor already do the same thing. Fixes: d52e7d5a952c ("x86/KASLR: Parse all 'memmap=' boot option entries") Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- arch/x86/boot/compressed/kaslr.c | 1 + 1 file changed, 1 insertion(+) -- 2.9.0