diff --git a/kernel/trace/trace_btf.c b/kernel/trace/trace_btf.c index b8370ae9bd54..adefd3969b1b 100644 --- a/kernel/trace/trace_btf.c +++ b/kernel/trace/trace_btf.c @@ -2,6 +2,7 @@ #include #include #include +#include #include "trace_btf.h" @@ -126,3 +127,85 @@ const struct btf_member *btf_find_struct_member(struct btf *btf, return member; } +void btf_trim_retval(unsigned long func, unsigned long *retval, bool *print_retval, + int *fmt, bool hex) +{ + const struct btf_type *t; + char name[KSYM_NAME_LEN]; + struct btf *btf; + u32 v, msb; + bool signed_type; + int kind; + + if (lookup_symbol_name(func, name)) + return; + + t = btf_find_func_proto(name, &btf); + if (IS_ERR_OR_NULL(t)) + return; + + t = btf_type_skip_modifiers(btf, t->type, NULL); + kind = t ? BTF_INFO_KIND(t->info) : BTF_KIND_UNKN; + switch (kind) { + case BTF_KIND_UNKN: + *print_retval = false; + break; + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: + case BTF_KIND_ENUM: + case BTF_KIND_ENUM64: + if (kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION) { + *fmt = RETVAL_FMT_HEX; + signed_type = false; + } else { + *fmt = RETVAL_FMT_DEC; + signed_type = btf_type_kflag(t); + if (!signed_type) + *fmt |= RETVAL_FMT_UNSIGNED; + } + + if (t->size > sizeof(unsigned long)) { + *fmt |= RETVAL_FMT_TRUNC; + msb = BITS_PER_LONG - 1; + } else { + msb = min_t(u32, BITS_PER_BYTE * t->size - 1, + BITS_PER_LONG - 1); + *retval &= GENMASK(msb, 0); + } + if (signed_type && t->size && !hex) + *retval = sign_extend64(*retval, msb); + break; + case BTF_KIND_INT: + v = *(u32 *)(t + 1); + signed_type = false; + if (BTF_INT_ENCODING(v) == BTF_INT_BOOL) { + *fmt = RETVAL_FMT_BOOL; + msb = 0; + } else { + signed_type = BTF_INT_ENCODING(v) & BTF_INT_SIGNED; + if (signed_type) + *fmt = RETVAL_FMT_DEC; + else + *fmt = RETVAL_FMT_HEX; + + if (t->size > sizeof(unsigned long)) { + *fmt |= RETVAL_FMT_TRUNC; + msb = BITS_PER_LONG - 1; + } else { + msb = min_t(u32, BTF_INT_BITS(v) - 1, + BITS_PER_LONG - 1); + } + } + *retval &= GENMASK(msb, 0); + if (signed_type && !hex) + *retval = sign_extend64(*retval, msb); + break; + default: + *fmt = RETVAL_FMT_HEX; + break; + } + + if (*print_retval) + *fmt |= RETVAL_FMT_BTF; + btf_put(btf); +} diff --git a/kernel/trace/trace_btf.h b/kernel/trace/trace_btf.h index 4bd26bceae23..20cbc3d4ae0e 100644 --- a/kernel/trace/trace_btf.h +++ b/kernel/trace/trace_btf.h @@ -1,6 +1,15 @@ /* SPDX-License-Identifier: GPL-2.0 */ #include +enum { + RETVAL_FMT_HEX = BIT(0), + RETVAL_FMT_DEC = BIT(1), + RETVAL_FMT_BOOL = BIT(2), + RETVAL_FMT_TRUNC = BIT(3), + RETVAL_FMT_BTF = BIT(4), + RETVAL_FMT_UNSIGNED = BIT(5), +}; + const struct btf_type *btf_find_func_proto(const char *func_name, struct btf **btf_p); const struct btf_param *btf_get_func_param(const struct btf_type *func_proto, @@ -10,3 +19,12 @@ const struct btf_member *btf_find_struct_member(struct btf *btf, const char *member_name, u32 *anon_offset, const struct btf_type **member_type); +#ifdef CONFIG_DEBUG_INFO_BTF +void btf_trim_retval(unsigned long func, unsigned long *retval, bool *print_retval, + int *fmt, bool hex); +#else +static inline void btf_trim_retval(unsigned long func, unsigned long *retval, + bool *print_retval, int *fmt, bool hex) +{ +} +#endif diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index c5befd0c5b9a..78a608315dd3 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -15,6 +15,7 @@ #include "trace.h" #include "trace_output.h" +#include "trace_btf.h" /* When set, irq functions might be ignored */ static int ftrace_graph_skip_irqs; @@ -876,9 +877,10 @@ static void print_graph_retval(struct trace_seq *s, struct ftrace_graph_ent_entr { unsigned long err_code = 0; unsigned long retval = 0; + bool hex_format; bool print_retaddr = false; bool print_retval = false; - bool hex_format = !!(opt_flags & TRACE_GRAPH_PRINT_RETVAL_HEX); + int retval_fmt = 0; #ifdef CONFIG_FUNCTION_GRAPH_RETVAL retval = graph_ret->retval; @@ -889,17 +891,38 @@ static void print_graph_retval(struct trace_seq *s, struct ftrace_graph_ent_entr print_retaddr = !!(opt_flags & TRACE_GRAPH_PRINT_RETADDR); #endif - if (print_retval && retval && !hex_format) { - /* Check if the return value matches the negative format */ - if (IS_ENABLED(CONFIG_64BIT) && (retval & BIT(31)) && - (((u64)retval) >> 32) == 0) { - err_code = sign_extend64(retval, 31); - } else { - err_code = retval; - } + if (print_retval) { + int fmt = RETVAL_FMT_HEX; - if (!IS_ERR_VALUE(err_code)) - err_code = 0; + hex_format = !!(opt_flags & TRACE_GRAPH_PRINT_RETVAL_HEX); + btf_trim_retval((unsigned long)func, &retval, &print_retval, &fmt, + hex_format); + if (print_retval) { + if (hex_format) + retval_fmt = RETVAL_FMT_HEX; + + if (retval && retval_fmt != RETVAL_FMT_HEX && + !(fmt & RETVAL_FMT_BTF)) { + /* Check if the return value matches the negative format */ + if (IS_ENABLED(CONFIG_64BIT) && (retval & BIT(31)) && + (((u64)retval) >> 32) == 0) { + err_code = sign_extend64(retval, 31); + } else { + err_code = retval; + } + + if (!IS_ERR_VALUE(err_code)) + err_code = 0; + } + + if (retval_fmt == RETVAL_FMT_HEX) { + retval_fmt |= (fmt & RETVAL_FMT_TRUNC); + } else { + if (err_code && fmt & RETVAL_FMT_HEX) + fmt = (fmt & ~RETVAL_FMT_HEX) | RETVAL_FMT_DEC; + retval_fmt = fmt; + } + } } if (entry) { @@ -926,10 +949,17 @@ static void print_graph_retval(struct trace_seq *s, struct ftrace_graph_ent_entr trace_flags, false); if (print_retval) { - if (hex_format || (err_code == 0)) + if (retval_fmt & RETVAL_FMT_HEX) trace_seq_printf(s, " ret=0x%lx", retval); + else if (retval_fmt & RETVAL_FMT_BOOL) + trace_seq_printf(s, " ret=%s", retval ? "true" : "false"); + else if (retval_fmt & RETVAL_FMT_UNSIGNED) + trace_seq_printf(s, " ret=%lu", retval); else - trace_seq_printf(s, " ret=%ld", err_code); + trace_seq_printf(s, " ret=%ld", err_code ?: retval); + + if (retval_fmt & RETVAL_FMT_TRUNC) + trace_seq_printf(s, "(trunc)"); } if (!entry || print_retval || print_retaddr)