Re: [Crash-utility] [RFC PATCH 06/15] Support "mod -s|-S" options

On Thu, May 11, 2023 at 12:35 PM HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab(a)nec.com&gt; wrote: > Support "mod -s|-S" with introducing lm->load_sym{table,end} > > but many functions like "mod -d|-D" are still not supported. > > Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; > --- > defs.h | 9 +- > gdb-10.2.patch | 16 +++ > symbols.c | 350 ++++++++++++++++++++++++++++++++++++++++++++----- > 3 files changed, 340 insertions(+), 35 deletions(-) > > diff --git a/defs.h b/defs.h > index 95e44e8cb87c..b2478b6741ec 100644 > --- a/defs.h > +++ b/defs.h > @@ -2925,6 +2925,7 @@ struct mod_section_data { > ulong size; > int priority; > int flags; > + ulong addr; > Is it possible to reuse the member offset in module memory patches? I noticed that the offset is not used in the calculate_load_order_v3(). If it is doable to reuse the offset, that may avoid modifying the gdb patch? I haven't investigated the details.

}; > > /* This is unlikely to change, so imported from kernel for now. */ > @@ -2982,8 +2983,12 @@ struct load_module { > > /* For 6.4 module_memory */ > struct module_memory mem[MOD_MEM_NUM_TYPES]; - struct syment *symtable[MOD_MEM_NUM_TYPES]; > - struct syment *symend[MOD_MEM_NUM_TYPES]; > + struct syment **symtable; > + struct syment **symend; > Some similar member definitions are in the struct symbol_table_data and struct load_module, it looks confusing to me. But I'm not sure if it is better to move some of them to the struct symbol_talbe_data.

+ struct syment *ext_symtable[MOD_MEM_NUM_TYPES]; > + struct syment *ext_symend[MOD_MEM_NUM_TYPES]; > + struct syment *load_symtable[MOD_MEM_NUM_TYPES]; > + struct syment *load_symend[MOD_MEM_NUM_TYPES]; > int address_order[MOD_MEM_NUM_TYPES]; > int nr_mems; > }; > diff --git a/gdb-10.2.patch b/gdb-10.2.patch > index 835aae9859be..b3f6d8b086eb 100644 > --- a/gdb-10.2.patch > +++ b/gdb-10.2.patch > @@ -3120,3 +3120,19 @@ exit 0 > return result; > } > > +--- gdb-10.2/gdb/symtab.c.orig > ++++ gdb-10.2/gdb/symtab.c > +@@ -7515,8 +7515,11 @@ gdb_add_symbol_file(struct gnu_request * > + secname = lm->mod_section_data[i].name; > + if ((lm->mod_section_data[i].flags & > SEC_FOUND) && > + !STREQ(secname, ".text")) { > +- sprintf(buf, " -s %s 0x%lx", secname, > +- lm->mod_section_data[i].offset + > lm->mod_base); > ++ if (lm->mod_section_data[i].addr) > ++ sprintf(buf, " -s %s 0x%lx", > secname, lm->mod_section_data[i].addr); > ++ else > ++ sprintf(buf, " -s %s 0x%lx", > secname, > ++ > lm->mod_section_data[i].offset + lm->mod_base); > + strcat(req->buf, buf); > + } > + } > diff --git a/symbols.c b/symbols.c > index ef00ce0b79ca..8343081f51f7 100644 > --- a/symbols.c > +++ b/symbols.c > @@ -50,6 +50,8 @@ static void store_section_data(struct load_module *, bfd > *, asection *); > static void calculate_load_order_v1(struct load_module *, bfd *); > static void calculate_load_order_v2(struct load_module *, bfd *, int, > void *, long, unsigned int); > +static void calculate_load_order_v3(struct load_module *, bfd *, int, > + void *, long, unsigned int); static void check_insmod_builtin(struct load_module *, int, ulong *); > static int is_insmod_builtin(struct load_module *, struct syment *); > struct load_module; > @@ -2288,20 +2290,22 @@ store_module_symbols_v3(ulong total, int > mods_installed) > > for (sp = st->ext_module_symtable; sp < > st->ext_module_symend; sp++) { > if (STREQ(sp->name, buf1)) { > - lm->symtable[i] = sp; > + lm->ext_symtable[i] = sp; > break; > } > } > for ( ; sp < st->ext_module_symend; sp++) { > if (STREQ(sp->name, buf2)) { > - lm->symend[i] = sp; > + lm->ext_symend[i] = sp; > break; > } > } > > - if (lm->symtable[i] && lm->symend[i]) > - > mod_symtable_hash_install_range(lm->symtable[i], lm->symend[i]); > + if (lm->ext_symtable[i] && lm->ext_symend[i]) > + > mod_symtable_hash_install_range(lm->ext_symtable[i], lm->ext_symend[i]); > } > + lm->symtable = lm->ext_symtable; > + lm->symend = lm->ext_symend; > } > > st->flags |= MODULE_SYMS; > @@ -4090,15 +4094,27 @@ dump_symbol_table(void) > for (j = 0; j < lm->nr_mems; j++) > fprintf(fp, " %d", lm->address_order[j]); > fprintf(fp, "\n"); > + fprintf(fp, " symtable: %lx\n", > (ulong)lm->symtable); > + fprintf(fp, " ext_symtable: %lx\n", > (ulong)lm->ext_symtable); > + for (j = MOD_TEXT; j < MOD_MEM_NUM_TYPES; j++) { > + fprintf(fp, " ext_symtable[%d]: %lx > - %lx\n", > + j, (ulong)lm->ext_symtable[j], > (ulong)lm->ext_symend[j]); > + } > + fprintf(fp, " load_symtable: %lx\n", > (ulong)lm->load_symtable); > + for (j = MOD_TEXT; j < MOD_MEM_NUM_TYPES; j++) { > + fprintf(fp, " load_symtable[%d]: %lx > - %lx\n", > + j, (ulong)lm->load_symtable[j], > (ulong)lm->load_symend[j]); > + } > } > > for (s = 0; s < lm->mod_sections; s++) { > fprintf(fp, > - " %12s prio: %x flags: %05x offset: %-8lx size: > %lx\n", > + " %20s prio: %x flags: %08x offset: %-8lx addr: > %-16lx size: %lx\n", > lm->mod_section_data[s].name, > lm->mod_section_data[s].priority, > lm->mod_section_data[s].flags, > lm->mod_section_data[s].offset, > + lm->mod_section_data[s].addr, > lm->mod_section_data[s].size); > } > > @@ -12122,6 +12138,7 @@ store_section_data(struct load_module *lm, bfd > *bfd, asection *section) > } > lm->mod_section_data[i].size = bfd_section_size(section); > lm->mod_section_data[i].offset = 0; > + lm->mod_section_data[i].addr = 0; > if (strlen(name) < MAX_MOD_SEC_NAME) > strcpy(lm->mod_section_data[i].name, name); > else > @@ -12367,6 +12384,133 @@ calculate_load_order_v2(struct load_module *lm, > bfd *bfd, int dynamic, > } > } > > +/* Linux 6.4 and later */ > +static void > +calculate_load_order_v3(struct load_module *lm, bfd *bfd, int dynamic, > + void *minisyms, long symcount, unsigned int size) > +{ > + struct syment *s1, *s2; > + ulong sec_start; > + bfd_byte *from, *fromend; > + asymbol *store; > + asymbol *sym; > + symbol_info syminfo; > + char *secname; > + int i, j; > + > + if ((store = bfd_make_empty_symbol(bfd)) == NULL) > + error(FATAL, "bfd_make_empty_symbol() failed\n"); > + > + for (j = MOD_TEXT; j < MOD_MEM_NUM_TYPES; j++) { > + > The above for-loop is frequently used in these patches, can we introduce the following macro definition from the kernel? #define for_each_mod_mem_type(type) \ for (enum mod_mem_type (type) = 0; \ (type) < MOD_MEM_NUM_TYPES; (type)++) Looks more convenient to me.