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charset="utf-8" When tracing function validation, improve the reporting of alternative instruction by more clearly showing the different alternatives beginning and end. Signed-off-by: Alexandre Chartre --- tools/objtool/check.c | 18 +++----- tools/objtool/disas.c | 34 +++++++++++++++ tools/objtool/include/objtool/disas.h | 6 +++ tools/objtool/include/objtool/trace.h | 61 +++++++++++++++++++++++++++ tools/objtool/trace.c | 55 ++++++++++++++++++++++++ 5 files changed, 162 insertions(+), 12 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 93268b7c015e3..9321486e6265e 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3527,7 +3527,7 @@ static bool skip_alt_group(struct instruction *insn) =20 /* ANNOTATE_IGNORE_ALTERNATIVE */ if (insn->alt_group->ignore) { - TRACE_INSN(insn, "alt group ignored"); + TRACE_ALT(insn, "alt group ignored"); return true; } =20 @@ -3561,8 +3561,9 @@ static int validate_insn(struct objtool_file *file, s= truct symbol *func, struct instruction *prev_insn, struct instruction *next_insn, bool *dead_end) { - /* prev_state is not used if there is no disassembly support */ + /* prev_state and alt_name are not used if there is no disassembly suppor= t */ struct insn_state prev_state __maybe_unused; + char *alt_name __maybe_unused =3D NULL; struct alternative *alt; u8 visited; int ret; @@ -3649,24 +3650,17 @@ static int validate_insn(struct objtool_file *file,= struct symbol *func, return 1; =20 if (insn->alts) { - int i, num_alts; - - num_alts =3D 0; - for (alt =3D insn->alts; alt; alt =3D alt->next) - num_alts++; - - i =3D 1; for (alt =3D insn->alts; alt; alt =3D alt->next) { - TRACE_INSN(insn, "alternative %d/%d", i, num_alts); + TRACE_ALT_BEGIN(insn, alt, alt_name); ret =3D validate_branch(file, func, alt->insn, *statep); + TRACE_ALT_END(insn, alt, alt_name); if (ret) { BT_INSN(insn, "(alt)"); return ret; } - i++; } =20 - TRACE_INSN(insn, "alternative orig"); + TRACE_ALT_INFO_NOADDR(insn, "/ ", "DEFAULT"); } =20 if (skip_alt_group(insn)) diff --git a/tools/objtool/disas.c b/tools/objtool/disas.c index 181e4ce975d36..058e2053c31a7 100644 --- a/tools/objtool/disas.c +++ b/tools/objtool/disas.c @@ -3,6 +3,8 @@ * Copyright (C) 2015-2017 Josh Poimboeuf */ =20 +#define _GNU_SOURCE + #include #include #include @@ -427,6 +429,38 @@ size_t disas_insn(struct disas_context *dctx, struct i= nstruction *insn) return disasm(insn->offset, &dctx->info); } =20 +/* + * Provide a name for an alternative. + */ +char *disas_alt_name(struct alternative *alt) +{ + char *str =3D NULL; + + switch (alt->type) { + + case ALT_TYPE_EX_TABLE: + str =3D strdup("EXCEPTION"); + break; + + case ALT_TYPE_JUMP_TABLE: + str =3D strdup("JUMP"); + break; + + case ALT_TYPE_INSTRUCTIONS: + /* + * This is a non-default group alternative. Create a unique + * name using the offset of the first original and alternative + * instructions. + */ + asprintf(&str, "ALTERNATIVE %lx.%lx", + alt->insn->alt_group->orig_group->first_insn->offset, + alt->insn->alt_group->first_insn->offset); + break; + } + + return str; +} + /* * Disassemble a function. */ diff --git a/tools/objtool/include/objtool/disas.h b/tools/objtool/include/= objtool/disas.h index 5db75d06f2197..f1bef2a6003e8 100644 --- a/tools/objtool/include/objtool/disas.h +++ b/tools/objtool/include/objtool/disas.h @@ -6,6 +6,7 @@ #ifndef _DISAS_H #define _DISAS_H =20 +struct alternative; struct disas_context; struct disassemble_info; =20 @@ -24,6 +25,7 @@ void disas_print_info(FILE *stream, struct instruction *i= nsn, int depth, void disas_print_insn(FILE *stream, struct disas_context *dctx, struct instruction *insn, int depth, const char *format, ...); +char *disas_alt_name(struct alternative *alt); =20 #else /* DISAS */ =20 @@ -61,6 +63,10 @@ static inline void disas_print_info(FILE *stream, struct= instruction *insn, static inline void disas_print_insn(FILE *stream, struct disas_context *dc= tx, struct instruction *insn, int depth, const char *format, ...) {} +static inline char *disas_alt_name(struct alternative *alt) +{ + return NULL; +} =20 #endif /* DISAS */ =20 diff --git a/tools/objtool/include/objtool/trace.h b/tools/objtool/include/= objtool/trace.h index 5b8abdb9b09fb..9a608523b6b08 100644 --- a/tools/objtool/include/objtool/trace.h +++ b/tools/objtool/include/objtool/trace.h @@ -19,6 +19,21 @@ extern int trace_depth; fprintf(stderr, fmt, ##__VA_ARGS__); \ }) =20 +/* + * Print the instruction address and a message. The instruction + * itself is not printed. + */ +#define TRACE_ADDR(insn, fmt, ...) \ +({ \ + if (trace) { \ + disas_print_info(stderr, insn, trace_depth - 1, \ + fmt "\n", ##__VA_ARGS__); \ + } \ +}) + +/* + * Print the instruction address, the instruction and a message. + */ #define TRACE_INSN(insn, fmt, ...) \ ({ \ if (trace) { \ @@ -36,6 +51,36 @@ extern int trace_depth; trace_insn_state(insn, sprev, snext); \ }) =20 +#define TRACE_ALT_FMT(pfx, fmt) pfx " " fmt + +#define TRACE_ALT(insn, fmt, ...) \ + TRACE_INSN(insn, TRACE_ALT_FMT("", fmt), \ + (insn)->offset, ##__VA_ARGS__) + +#define TRACE_ALT_INFO(insn, pfx, fmt, ...) \ + TRACE_ADDR(insn, TRACE_ALT_FMT(pfx, fmt), \ + (insn)->offset, ##__VA_ARGS__) + +#define TRACE_ALT_INFO_NOADDR(insn, pfx, fmt, ...) \ + TRACE_ADDR(NULL, TRACE_ALT_FMT(pfx, fmt), \ + (insn)->offset, ##__VA_ARGS__) + +#define TRACE_ALT_BEGIN(insn, alt, alt_name) \ +({ \ + if (trace) { \ + alt_name =3D disas_alt_name(alt); \ + trace_alt_begin(insn, alt, alt_name); \ + } \ +}) + +#define TRACE_ALT_END(insn, alt, alt_name) \ +({ \ + if (trace) { \ + trace_alt_end(insn, alt, alt_name); \ + free(alt_name); \ + } \ +}) + static inline void trace_enable(void) { trace =3D true; @@ -61,17 +106,33 @@ static inline void trace_depth_dec(void) =20 void trace_insn_state(struct instruction *insn, struct insn_state *sprev, struct insn_state *snext); +void trace_alt_begin(struct instruction *orig_insn, struct alternative *al= t, + char *alt_name); +void trace_alt_end(struct instruction *orig_insn, struct alternative *alt, + char *alt_name); =20 #else /* DISAS */ =20 #define TRACE(fmt, ...) +#define TRACE_ADDR(insn, fmt, ...) #define TRACE_INSN(insn, fmt, ...) #define TRACE_INSN_STATE(insn, sprev, snext) +#define TRACE_ALT(insn, fmt, ...) +#define TRACE_ALT_INFO(insn, fmt, ...) +#define TRACE_ALT_INFO_NOADDR(insn, fmt, ...) +#define TRACE_ALT_BEGIN(insn, alt, alt_name) +#define TRACE_ALT_END(insn, alt, alt_name) =20 static inline void trace_enable(void) {} static inline void trace_disable(void) {} static inline void trace_depth_inc(void) {} static inline void trace_depth_dec(void) {} +static inline void trace_alt_begin(struct instruction *orig_insn, + struct alternative *alt, + char *alt_name) {}; +static inline void trace_alt_end(struct instruction *orig_insn, + struct alternative *alt, + char *alt_name) {}; =20 #endif =20 diff --git a/tools/objtool/trace.c b/tools/objtool/trace.c index ef9250d4646bb..1c3d961b5123a 100644 --- a/tools/objtool/trace.c +++ b/tools/objtool/trace.c @@ -147,3 +147,58 @@ void trace_insn_state(struct instruction *insn, struct= insn_state *sprev, =20 insn->trace =3D 1; } + +void trace_alt_begin(struct instruction *orig_insn, struct alternative *al= t, + char *alt_name) +{ + struct instruction *alt_insn; + char suffix[2]; + + alt_insn =3D alt->insn; + + if (alt->type =3D=3D ALT_TYPE_EX_TABLE) { + /* + * When there is an exception table then the instruction + * at the original location is executed but it can cause + * an exception. In that case, the execution will be + * redirected to the alternative instruction. + * + * The instruction at the original location can have + * instruction alternatives, so we just print the location + * of the instruction that can cause the exception and + * not the instruction itself. + */ + TRACE_ALT_INFO_NOADDR(orig_insn, "/ ", "%s for instruction at 0x%lx <%s+= 0x%lx>", + alt_name, + orig_insn->offset, orig_insn->sym->name, + orig_insn->offset - orig_insn->sym->offset); + } else { + TRACE_ALT_INFO_NOADDR(orig_insn, "/ ", "%s", alt_name); + } + + if (alt->type =3D=3D ALT_TYPE_JUMP_TABLE) { + /* + * For a jump alternative, if the default instruction is + * a NOP then it is replaced with the jmp instruction, + * otherwise it is replaced with a NOP instruction. + */ + trace_depth++; + if (orig_insn->type =3D=3D INSN_NOP) { + suffix[0] =3D (orig_insn->len =3D=3D 5) ? 'q' : '\0'; + TRACE_ADDR(orig_insn, "jmp%-3s %lx <%s+0x%lx>", suffix, + alt_insn->offset, alt_insn->sym->name, + alt_insn->offset - alt_insn->sym->offset); + } else { + TRACE_ADDR(orig_insn, "NOP%d", orig_insn->len); + trace_depth--; + } + } +} + +void trace_alt_end(struct instruction *orig_insn, struct alternative *alt, + char *alt_name) +{ + if (alt->type =3D=3D ALT_TYPE_JUMP_TABLE && orig_insn->type =3D=3D INSN_N= OP) + trace_depth--; + TRACE_ALT_INFO_NOADDR(orig_insn, "\\ ", "%s end", alt_name); +} --=20 2.43.5