From 7acabef3b09b9121d38d4d46745e5b3df69a69eb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20Chigot?= Date: Wed, 23 Jun 2021 13:09:44 +0200 Subject: [PATCH] libbacktrace: fix DWARF suppport for XCOFF files A few thing were missing to correctly handle DWARF files on AIX. Moreover, the prevously base_addres was the starting address of the .text section of a loaded file instead of the difference between this starting address and the starting address in the file itself (unloaded). --- libbacktrace/xcoff.c | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-) diff --git a/libbacktrace/xcoff.c b/libbacktrace/xcoff.c index f9bcf9f6ce7..258d0b30354 100644 --- a/libbacktrace/xcoff.c +++ b/libbacktrace/xcoff.c @@ -133,6 +133,7 @@ typedef struct { #define SSUBTYP_DWARNGE 0x50000 /* DWARF aranges section. */ #define SSUBTYP_DWABREV 0x60000 /* DWARF abbreviation section. */ #define SSUBTYP_DWSTR 0x70000 /* DWARF strings section. */ +#define SSUBTYP_DWRNGES 0x80000 /* DWARF ranges section. */ /* XCOFF symbol. */ @@ -264,6 +265,7 @@ typedef struct { #define XCOFF_AIX_TEXTBASE 0x100000000ul #endif + /* AIX big archive fixed-length header. */ #define AIAMAGBIG "\n" @@ -586,7 +588,6 @@ xcoff_symname (const b_xcoff_syment *asym, static int xcoff_initialize_syminfo (struct backtrace_state *state, uintptr_t base_address, - const b_xcoff_scnhdr *sects, const b_xcoff_syment *syms, size_t nsyms, const unsigned char *strtab, size_t strtab_size, backtrace_error_callback error_callback, void *data, @@ -631,8 +632,7 @@ xcoff_initialize_syminfo (struct backtrace_state *state, { const b_xcoff_auxent *aux = (const b_xcoff_auxent *) (asym + 1); xcoff_symbols[j].name = xcoff_symname (asym, strtab, strtab_size); - xcoff_symbols[j].address = base_address + asym->n_value - - sects[asym->n_scnum - 1].s_paddr; + xcoff_symbols[j].address = base_address + asym->n_value; /* x_fsize will be 0 if there is no debug information. */ xcoff_symbols[j].size = aux->x_fcn.x_fsize; ++j; @@ -770,7 +770,7 @@ xcoff_lookup_pc (struct backtrace_state *state ATTRIBUTE_UNUSED, lineno = (const b_xcoff_lineno *) lineptr; if (lineno->l_lnno == 0) break; - if (pc <= fdata->base_address + lineno->l_addr.l_paddr - fn->sect_base) + if (pc <= fdata->base_address + lineno->l_addr.l_paddr) break; match = lnnoptr; lnno = lineno->l_lnno; @@ -1005,7 +1005,7 @@ xcoff_initialize_fileline (struct backtrace_state *state, fn->name = xcoff_symname (fsym, strtab, strtab_size); fn->filename = filename; fn->sect_base = sects[fsym->n_scnum - 1].s_paddr; - fn->pc = base_address + fsym->n_value - fn->sect_base; + fn->pc = base_address + fsym->n_value; fn->size = fsize; fn->lnno = lnno; fn->lnnoptr = lnnoptr; @@ -1156,8 +1156,15 @@ xcoff_add (struct backtrace_state *state, int descriptor, off_t offset, stext = §s[i]; - /* AIX ldinfo_textorg includes the XCOFF headers. */ - base_address = (exe ? XCOFF_AIX_TEXTBASE : base_address) + stext->s_scnptr; + /* base_address represents the difference between the + virtual memory address of the shared object or a loaded + executable and the offset of that object in the file + from which it was loaded. + On AIX, virtual address is either fixed for executable + or given by ldinfo. This address will include the XCOFF + headers. */ + base_address = (exe ? XCOFF_AIX_TEXTBASE : base_address) + stext->s_scnptr + - stext->s_paddr; lnnoptr = stext->s_lnnoptr; nlnno = stext->s_nlnno; @@ -1215,7 +1222,7 @@ xcoff_add (struct backtrace_state *state, int descriptor, off_t offset, if (sdata == NULL) goto fail; - if (!xcoff_initialize_syminfo (state, base_address, sects, + if (!xcoff_initialize_syminfo (state, base_address, syms_view.data, fhdr.f_nsyms, str_view.data, str_size, error_callback, data, sdata)) @@ -1255,7 +1262,7 @@ xcoff_add (struct backtrace_state *state, int descriptor, off_t offset, case SSUBTYP_DWABREV: idx = DEBUG_ABBREV; break; - case SSUBTYP_DWARNGE: + case SSUBTYP_DWRNGES: idx = DEBUG_RANGES; break; case SSUBTYP_DWSTR: @@ -1293,13 +1300,7 @@ xcoff_add (struct backtrace_state *state, int descriptor, off_t offset, dwarf_sections.data[DEBUG_INFO] = dwsect[DEBUG_INFO].data; dwarf_sections.size[DEBUG_INFO] = dwsect[DEBUG_INFO].size; -#if BACKTRACE_XCOFF_SIZE == 32 - /* XXX workaround for broken lineoff */ - dwarf_sections.data[DEBUG_LINE] = dwsect[DEBUG_LINE].data - 4; -#else - /* XXX workaround for broken lineoff */ - dwarf_sections.data[DEBUG_LINE] = dwsect[DEBUG_LINE].data - 12; -#endif + dwarf_sections.data[DEBUG_LINE] = dwsect[DEBUG_LINE].data; dwarf_sections.size[DEBUG_LINE] = dwsect[DEBUG_LINE].size; dwarf_sections.data[DEBUG_ABBREV] = dwsect[DEBUG_ABBREV].data; dwarf_sections.size[DEBUG_ABBREV] = dwsect[DEBUG_ABBREV].size; @@ -1308,7 +1309,7 @@ xcoff_add (struct backtrace_state *state, int descriptor, off_t offset, dwarf_sections.data[DEBUG_STR] = dwsect[DEBUG_STR].data; dwarf_sections.size[DEBUG_STR] = dwsect[DEBUG_STR].size; - if (!backtrace_dwarf_add (state, 0, &dwarf_sections, + if (!backtrace_dwarf_add (state, base_address, &dwarf_sections, 1, /* big endian */ NULL, /* altlink */ error_callback, data, fileline_fn, -- 2.31.1