Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
objtool: Improve naming of group alternatives
Improve the naming of group alternatives by showing the feature name and
flags used by the alternative.
Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-28-alexandre.chartre@oracle.com
authored by
Alexandre Chartre
and committed by
Peter Zijlstra
56967b9a
8308fd00
+52
-6
+52
-6
tools/objtool/disas.c
+52
-6
tools/objtool/disas.c
···
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#include <objtool/arch.h>
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#include <objtool/check.h>
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#include <objtool/disas.h>
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#include <objtool/special.h>
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#include <objtool/warn.h>
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#include <bfd.h>
···
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#define DALT_INSN(dalt) (DALT_DEFAULT(dalt) ? (dalt)->orig_insn : (dalt)->alt->insn)
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#define DALT_GROUP(dalt) (DALT_INSN(dalt)->alt_group)
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#define DALT_ALTID(dalt) ((dalt)->orig_insn->offset)
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#define ALT_FLAGS_SHIFT 16
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#define ALT_FLAG_NOT (1 << 0)
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#define ALT_FLAG_DIRECT_CALL (1 << 1)
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#define ALT_FEATURE_MASK ((1 << ALT_FLAGS_SHIFT) - 1)
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static int alt_feature(unsigned int ft_flags)
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{
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return (ft_flags & ALT_FEATURE_MASK);
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}
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static int alt_flags(unsigned int ft_flags)
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{
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return (ft_flags >> ALT_FLAGS_SHIFT);
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}
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/*
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* Wrapper around asprintf() to allocate and format a string.
···
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*/
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char *disas_alt_name(struct alternative *alt)
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{
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char pfx[4] = { 0 };
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char *str = NULL;
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const char *name;
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int feature;
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int flags;
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int num;
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switch (alt->type) {
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···
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case ALT_TYPE_INSTRUCTIONS:
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/*
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* This is a non-default group alternative. Create a unique
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* name using the offset of the first original and alternative
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* instructions.
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* This is a non-default group alternative. Create a name
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* based on the feature and flags associated with this
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* alternative. Use either the feature name (it is available)
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* or the feature number. And add a prefix to show the flags
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* used.
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*
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* Prefix flags characters:
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*
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* '!' alternative used when feature not enabled
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* '+' direct call alternative
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* '?' unknown flag
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*/
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asprintf(&str, "ALTERNATIVE %lx.%lx",
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alt->insn->alt_group->orig_group->first_insn->offset,
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alt->insn->alt_group->first_insn->offset);
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feature = alt->insn->alt_group->feature;
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num = alt_feature(feature);
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flags = alt_flags(feature);
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str = pfx;
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if (flags & ~(ALT_FLAG_NOT | ALT_FLAG_DIRECT_CALL))
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*str++ = '?';
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if (flags & ALT_FLAG_DIRECT_CALL)
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*str++ = '+';
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if (flags & ALT_FLAG_NOT)
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*str++ = '!';
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name = arch_cpu_feature_name(num);
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if (!name)
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str = strfmt("%sFEATURE 0x%X", pfx, num);
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else
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str = strfmt("%s%s", pfx, name);
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break;
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}
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···
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WARN("%s has more alternatives than supported", alt_name);
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break;
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}
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dalt = &dalts[i];
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err = disas_alt_init(dalt, orig_insn, alt);
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if (err) {