Trying to build the kernel with CONFIG_INFINIBAND_USER_ACCESS enabled fails
ERROR: "__get_user_unknown" [drivers/infiniband/core/ib_uverbs.ko] undefined!
with on SH since the kernel misses a 64-bit implementation of get_user().
Implement the missing 64-bit get_user() as __get_user_u64(), matching the
already existing __put_user_u64() which implements the 64-bit put_user().
Signed-off-by: John Paul Adrian Glaubitz <[email protected]>
---
arch/sh/include/asm/uaccess_32.h | 51 ++++++++++++++++++++++++++++++++
1 file changed, 51 insertions(+)
Changes since v1:
- Replace single mov instruction for exception handling
in case of invalid load
diff --git a/arch/sh/include/asm/uaccess_32.h b/arch/sh/include/asm/uaccess_32.h
index 624cf55acc27..35f6c1e40ec3 100644
--- a/arch/sh/include/asm/uaccess_32.h
+++ b/arch/sh/include/asm/uaccess_32.h
@@ -26,6 +26,9 @@ do { \
case 4: \
__get_user_asm(x, ptr, retval, "l"); \
break; \
+ case 8: \
+ __get_user_u64(x, ptr, retval); \
+ break; \
default: \
__get_user_unknown(); \
break; \
@@ -66,6 +69,54 @@ do { \
extern void __get_user_unknown(void);
+#if defined(CONFIG_CPU_LITTLE_ENDIAN)
+#define __get_user_u64(x, addr, err) \
+({ \
+__asm__ __volatile__( \
+ "1:\n\t" \
+ "mov.l %2,%R1\n\t" \
+ "mov.l %T2,%S1\n\t" \
+ "2:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "3:\n\t" \
+ "mov #0,%R1\n\t" \
+ "mov #0,%S1\n\t" \
+ "mov.l 4f, %0\n\t" \
+ "jmp @%0\n\t" \
+ " mov %3, %0\n\t" \
+ ".balign 4\n" \
+ "4: .long 2b\n\t" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n\t" \
+ ".long 1b, 3b\n\t" \
+ ".previous" \
+ :"=&r" (err), "=&r" (x) \
+ :"m" (__m(addr)), "i" (-EFAULT), "0" (err)); })
+#else
+#define __get_user_u64(x, addr, err) \
+({ \
+__asm__ __volatile__( \
+ "1:\n\t" \
+ "mov.l %2,%S1\n\t" \
+ "mov.l %T2,%R1\n\t" \
+ "2:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "3:\n\t" \
+ "mov #0,%S1\n\t" \
+ "mov #0,%R1\n\t" \
+ "mov.l 4f, %0\n\t" \
+ "jmp @%0\n\t" \
+ " mov %3, %0\n\t" \
+ ".balign 4\n" \
+ "4: .long 2b\n\t" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n\t" \
+ ".long 1b, 3b\n\t" \
+ ".previous" \
+ :"=&r" (err), "=&r" (x) \
+ :"m" (__m(addr)), "i" (-EFAULT), "0" (err)); })
+#endif
+
#define __put_user_size(x,ptr,size,retval) \
do { \
retval = 0; \
--
2.27.0.rc2
Hi!
On 5/31/20 12:47 PM, John Paul Adrian Glaubitz wrote:
> Changes since v1:
> - Replace single mov instruction for exception handling
> in case of invalid load
Yutaka Niibe has had a look at my patch and he says, we might have to add
an entry for the fault handling of the upper word.
Quote:
> (1) I think that there is possibility that the second access to user
> space fails (while the first access succeeds). IIUC, it's good have
> an entry in __ex_tables for the second access too, like:
> ".long 1b+2, 3b\n\t"
> I don't know if the expression "1b+2" is correct, my intention is
> detecting the failure in the seccond access.
Comments?
@Sato-san: Can you comment on the patch as well?
Thanks,
Adrian
--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer - [email protected]
`. `' Freie Universitaet Berlin - [email protected]
`- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
Hi Adrian,
On Wed, Jun 3, 2020 at 9:20 AM John Paul Adrian Glaubitz
<[email protected]> wrote:
> On 5/31/20 12:47 PM, John Paul Adrian Glaubitz wrote:
> > Changes since v1:
> > - Replace single mov instruction for exception handling
> > in case of invalid load
>
> Yutaka Niibe has had a look at my patch and he says, we might have to add
> an entry for the fault handling of the upper word.
>
> Quote:
>
> > (1) I think that there is possibility that the second access to user
> > space fails (while the first access succeeds). IIUC, it's good have
> > an entry in __ex_tables for the second access too, like:
> > ".long 1b+2, 3b\n\t"
> > I don't know if the expression "1b+2" is correct, my intention is
> > detecting the failure in the seccond access.
So just add another numeric label, like is done on m68k.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds