| Message ID | 20200531104715.2512247-1-glaubitz@physik.fu-berlin.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] sh: Implement __get_user_u64() required for 64-bit get_user() | expand |
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
Hi Adrian, On Wed, Jun 3, 2020 at 9:20 AM John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> 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
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; \
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 <glaubitz@physik.fu-berlin.de> --- 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