Re: [Crash-utility] [PATCH 1/3] arm64: relax symbol filters

Below is a (hardly tested, pretty messy, incomplete - needs to address other architectures verify_symbol() prototypes) patch that illustrates this idea. I'm OK with special casing _kernel_flags_le, but generally prefer to look for general solutions. Let me know if you like anything in the patch below, if so, then I can clean it up and send it properly. The patch takes care of the two cases pointed above, i.e. 'sym -l' and 'rd -S'. Thanks, drew

Author: Andrew Jones <drjones(a)redhat.com&gt; Date: Thu Nov 19 19:31:28 2015 +0100 symbols: keep absolutes, but handle specially diff --git a/arm64.c b/arm64.c index 91b35787e6942..534d301c39afd 100644 --- a/arm64.c +++ b/arm64.c @@ -24,7 +24,7 @@ #define NOT_IMPLEMENTED(X) error((X), "%s: function not implemented\n", __func__) static struct machine_specific arm64_machine_specific = { 0 }; -static int arm64_verify_symbol(const char *, ulong, char); +static int arm64_verify_symbol(const char *, ulong, char, unsigned char *); static void arm64_parse_cmdline_args(void); static void arm64_calc_phys_offset(void); static void arm64_calc_virtual_memory_ranges(void); @@ -330,7 +330,7 @@ arm64_init(int when) * Accept or reject a symbol from the kernel namelist. */ static int -arm64_verify_symbol(const char *name, ulong value, char type) +arm64_verify_symbol(const char *name, ulong value, char type, unsigned char *flags) { if (!name || !strlen(name)) return FALSE; @@ -345,9 +345,13 @@ arm64_verify_symbol(const char *name, ulong value, char type) if (STREQ(name, "$d") || STREQ(name, "$x")) return FALSE; - if ((type == 'A') && (STRNEQ(name, "__crc_") || STRNEQ(name, "__reg_num_"))) + if ((type == 'A' || type == 'a') && + (STRNEQ(name, "__crc_") || STRNEQ(name, "__reg_num_"))) return FALSE; + if ((type == 'A' || type == 'a') && flags) + *flags |= SYMBOL_NO_OFFSET; + if (!(machdep->flags & KSYMS_START) && STREQ(name, "idmap_pg_dir")) machdep->flags |= KSYMS_START; diff --git a/defs.h b/defs.h index 981b030cc6688..3b6fd15496063 100644 --- a/defs.h +++ b/defs.h @@ -969,7 +969,7 @@ struct machdep_table { uint64_t (*memory_size)(void); ulong (*vmalloc_start)(void); int (*is_task_addr)(ulong); - int (*verify_symbol)(const char *, ulong, char); + int (*verify_symbol)(const char *, ulong, char, unsigned char *); int (*dis_filter)(ulong, char *, unsigned int); int (*get_smp_cpus)(void); int (*is_kvaddr)(ulong); @@ -2412,6 +2412,7 @@ struct rb_root #define SYMBOL_NAME_USED (0x1) #define MODULE_SYMBOL (0x2) +#define SYMBOL_NO_OFFSET (0x4) #define IS_MODULE_SYMBOL(SYM) ((SYM)->flags & MODULE_SYMBOL) struct syment { diff --git a/symbols.c b/symbols.c index 5a2aa7ccb5713..bcd2e4e1947fb 100644 --- a/symbols.c +++ b/symbols.c @@ -716,6 +716,8 @@ store_symbols(bfd *abfd, int dynamic, void *minisyms, long symcount, for (; from < fromend; from += size) { + unsigned char flags = 0; + if ((sym = bfd_minisymbol_to_symbol(abfd, dynamic, from, store)) == NULL) error(FATAL, "bfd_minisymbol_to_symbol() failed\n"); @@ -724,13 +726,14 @@ store_symbols(bfd *abfd, int dynamic, void *minisyms, long symcount, name = strip_symbol_end(syminfo.name, buf); if (machdep->verify_symbol(name, syminfo.value, - syminfo.type)) { + syminfo.type, &flags)) { if (kt->flags & (RELOC_SET|RELOC_FORCE)) sp->value = relocate(syminfo.value, (char *)syminfo.name, !(first++)); else sp->value = syminfo.value; sp->type = syminfo.type; + sp->flags = flags; namespace_ctl(NAMESPACE_INSTALL, &st->kernel_namespace, sp, name); sp++; @@ -789,6 +792,9 @@ store_sysmap_symbols(void) rewind(map); while (fgets(buf, BUFSIZE, map)) { + + unsigned char flags = 0; + if ((c = parse_line(buf, mapitems)) != 3) continue; @@ -800,13 +806,14 @@ store_sysmap_symbols(void) strip_symbol_end(name, NULL); if (machdep->verify_symbol(name, syment.value, - syment.type)) { + syment.type, &flags)) { if (kt->flags & RELOC_SET) sp->value = relocate(syment.value, syment.name, !(first++)); else sp->value = syment.value; sp->type = syment.type; + sp->flags = flags; namespace_ctl(NAMESPACE_INSTALL, &st->kernel_namespace, sp, name); sp++; @@ -2243,7 +2250,7 @@ store_module_kallsyms_v2(struct load_module *lm, int start, int curr, * Make sure that these don't end up into our symbol list. */ if (machine_type("ARM") && - !machdep->verify_symbol(nameptr, ec->st_value, ec->st_info)) + !machdep->verify_symbol(nameptr, ec->st_value, ec->st_info, NULL)) continue; if (CRASHDEBUG(7)) @@ -3908,7 +3915,12 @@ show_symbol(struct syment *sp, ulong offset, ulong show_flags) fprintf(fp, (radix == 16) ? "%lx (%c) %s+0x%lx" : "%lx (%c) %s+%ld", sp->value+offset, sp->type, sp->name, offset); - else + else if (highest_bit_long(sp->value) != highest_bit_long(ULONG_MAX)) + if (highest_bit_long(ULONG_MAX) > 31) + fprintf(fp, "%016lx (%c) %s", sp->value, sp->type, sp->name); + else + fprintf(fp, "%08lx (%c) %s", sp->value, sp->type, sp->name); + else fprintf(fp, "%lx (%c) %s", sp->value, sp->type, sp->name); if (lm) @@ -4692,7 +4704,7 @@ value_to_symstr(ulong value, char *buf, ulong radix) if ((radix != 10) && (radix != 16)) radix = 16; - if ((sp = value_search(value, &offset))) { + if ((sp = value_search(value, &offset)) && !(sp->flags & SYMBOL_NO_OFFSET)) { if (offset) sprintf(buf, radix == 16 ? "%s+0x%lx" : "%s+%ld", sp->name, offset); @@ -11446,14 +11458,15 @@ store_load_module_symbols(bfd *bfd, int dynamic, void *minisyms, } if (found) { + unsigned char flags = 0; strcpy(name, syminfo.name); strip_module_symbol_end(name); strip_symbol_end(name, NULL); if (machdep->verify_symbol(name, syminfo.value, - syminfo.type)) { + syminfo.type, &flags)) { sp->value = syminfo.value; sp->type = syminfo.type; - sp->flags |= MODULE_SYMBOL; + sp->flags |= (MODULE_SYMBOL | flags); namespace_ctl(NAMESPACE_INSTALL, &lm->mod_load_namespace, sp, name);