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50934945d5
The 'ld' instruction requires a 4-byte aligned displacement because it
is a DS-form instruction. But the "m" asm constraint doesn't enforce
that.
Add a special case of __get_user_asm2_goto() so that the "YZ" constraint
can be used for "ld".
The "Z" constraint is documented in the GCC manual PowerPC machine
constraints, and specifies a "memory operand accessed with indexed or
indirect addressing". "Y" is not documented in the manual but specifies
a "memory operand for a DS-form instruction". Using both allows the
compiler to generate a DS-form "ld" or X-form "ldx" as appropriate.
The change has to be conditional on CONFIG_PPC_KERNEL_PREFIXED because
the "Y" constraint does not guarantee 4-byte alignment when prefixed
instructions are enabled.
No build errors have been reported due to this, but the possibility is
there depending on compiler code generation decisions.
Fixes:
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asm | ||
uapi/asm |