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arm64: insn: Provide a better name for aarch64_insn_is_nop()
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The current aarch64_insn_is_nop() has exactly one caller which uses it
solely to identify if the instruction is a HINT that can safely be stepped,
requiring us to list things that aren't NOPs and make things more confusing
than they need to be. Rename the function to reflect the actual usage and
make things more clear.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20200504131326.18290-3-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
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Mark Brown authored and Will Deacon committed May 4, 2020
1 parent bd507ca commit 07dcd96
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Showing 3 changed files with 3 additions and 4 deletions.
2 changes: 1 addition & 1 deletion arch/arm64/include/asm/insn.h
Original file line number Diff line number Diff line change
Expand Up @@ -368,7 +368,7 @@ __AARCH64_INSN_FUNCS(msr_reg, 0xFFF00000, 0xD5100000)

#undef __AARCH64_INSN_FUNCS

bool aarch64_insn_is_nop(u32 insn);
bool aarch64_insn_is_steppable_hint(u32 insn);
bool aarch64_insn_is_branch_imm(u32 insn);

static inline bool aarch64_insn_is_adr_adrp(u32 insn)
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3 changes: 1 addition & 2 deletions arch/arm64/kernel/insn.c
Original file line number Diff line number Diff line change
Expand Up @@ -51,8 +51,7 @@ enum aarch64_insn_encoding_class __kprobes aarch64_get_insn_class(u32 insn)
return aarch64_insn_encoding_class[(insn >> 25) & 0xf];
}

/* NOP is an alias of HINT */
bool __kprobes aarch64_insn_is_nop(u32 insn)
bool __kprobes aarch64_insn_is_steppable_hint(u32 insn)
{
if (!aarch64_insn_is_hint(insn))
return false;
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2 changes: 1 addition & 1 deletion arch/arm64/kernel/probes/decode-insn.c
Original file line number Diff line number Diff line change
Expand Up @@ -46,7 +46,7 @@ static bool __kprobes aarch64_insn_is_steppable(u32 insn)
* except for the NOP case.
*/
if (aarch64_insn_is_hint(insn))
return aarch64_insn_is_nop(insn);
return aarch64_insn_is_steppable_hint(insn);

return true;
}
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