From e92b85e1ffaa0bd8e5d92e7c378a3909e7f23122 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 25 Feb 2010 08:35:50 -0500 Subject: [PATCH] perf probe: Use libdw callback routines Use libdw callback functions aggressively, and remove local tree-search API. This change simplifies the code. Changes in v3: - Cast Dwarf_Addr to uintmax_t for printf-formats. Changes in v2: - Cast Dwarf_Addr to unsigned long long for printf-formats. Signed-off-by: Masami Hiramatsu Cc: systemtap Cc: DLE Cc: Frederic Weisbecker Cc: Arnaldo Carvalho de Melo Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Mike Galbraith Cc: K.Prasad Cc: Ulrich Drepper Cc: Roland McGrath Cc: Frederic Weisbecker Cc: Ananth N Mavinakayanahalli LKML-Reference: <20100225133549.6725.81499.stgit@localhost6.localdomain6> Signed-off-by: Ingo Molnar --- tools/perf/util/probe-finder.c | 262 ++++++++++++++--------------------------- tools/perf/util/probe-finder.h | 1 - 2 files changed, 86 insertions(+), 177 deletions(-) diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index c422472..6305f34 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -38,13 +38,6 @@ #include "probe-finder.h" -/* Dwarf_Die Linkage to parent Die */ -struct die_link { - struct die_link *parent; /* Parent die */ - Dwarf_Die die; /* Current die */ -}; - - /* * Generic dwarf analysis helpers */ @@ -177,26 +170,6 @@ static bool die_compare_name(Dwarf_Die *dw_die, const char *tname) return strcmp(tname, name); } -/* Check the address is in the subprogram(function). */ -static bool die_within_subprogram(Dwarf_Die *sp_die, Dwarf_Addr addr, - size_t *offs) -{ - Dwarf_Addr epc; - int ret; - - ret = dwarf_haspc(sp_die, addr); - if (ret <= 0) - return false; - - if (offs) { - ret = dwarf_entrypc(sp_die, &epc); - DIE_IF(ret == -1); - *offs = addr - epc; - } - - return true; -} - /* Get entry pc(or low pc, 1st entry of ranges) of the die */ static Dwarf_Addr die_get_entrypc(Dwarf_Die *dw_die) { @@ -208,70 +181,34 @@ static Dwarf_Addr die_get_entrypc(Dwarf_Die *dw_die) return epc; } -/* Check if the abstract origin's address or not */ -static bool die_compare_abstract_origin(Dwarf_Die *in_die, void *origin_addr) -{ - Dwarf_Attribute attr; - Dwarf_Die origin; - - if (!dwarf_attr(in_die, DW_AT_abstract_origin, &attr)) - return false; - if (!dwarf_formref_die(&attr, &origin)) - return false; - - return origin.addr == origin_addr; -} - -/* - * Search a Die from Die tree. - * Note: cur_link->die should be deallocated in this function. - */ -static int __search_die_tree(struct die_link *cur_link, - int (*die_cb)(struct die_link *, void *), - void *data) +/* Get a variable die */ +static Dwarf_Die *die_find_variable(Dwarf_Die *sp_die, const char *name, + Dwarf_Die *die_mem) { - struct die_link new_link; + Dwarf_Die child_die; + int tag; int ret; - if (!die_cb) - return 0; - - /* Check current die */ - while (!(ret = die_cb(cur_link, data))) { - /* Check child die */ - ret = dwarf_child(&cur_link->die, &new_link.die); - if (ret == 0) { - new_link.parent = cur_link; - ret = __search_die_tree(&new_link, die_cb, data); - if (ret) - break; - } + ret = dwarf_child(sp_die, die_mem); + if (ret != 0) + return NULL; - /* Move to next sibling */ - ret = dwarf_siblingof(&cur_link->die, &cur_link->die); - if (ret != 0) - return 0; - } - return ret; -} + do { + tag = dwarf_tag(die_mem); + if ((tag == DW_TAG_formal_parameter || + tag == DW_TAG_variable) && + (die_compare_name(die_mem, name) == 0)) + return die_mem; -/* Search a die in its children's die tree */ -static int search_die_from_children(Dwarf_Die *parent_die, - int (*die_cb)(struct die_link *, void *), - void *data) -{ - struct die_link new_link; - int ret; + if (die_find_variable(die_mem, name, &child_die)) { + memcpy(die_mem, &child_die, sizeof(Dwarf_Die)); + return die_mem; + } + } while (dwarf_siblingof(die_mem, die_mem) == 0); - new_link.parent = NULL; - ret = dwarf_child(parent_die, &new_link.die); - if (ret == 0) - return __search_die_tree(&new_link, die_cb, data); - else - return 0; + return NULL; } - /* * Probe finder related functions */ @@ -347,28 +284,13 @@ error: " Perhaps, it has been optimized out.", pf->var); } -static int variable_search_cb(struct die_link *dlink, void *data) -{ - struct probe_finder *pf = (struct probe_finder *)data; - int tag; - - tag = dwarf_tag(&dlink->die); - DIE_IF(tag < 0); - if ((tag == DW_TAG_formal_parameter || - tag == DW_TAG_variable) && - (die_compare_name(&dlink->die, pf->var) == 0)) { - show_variable(&dlink->die, pf); - return 1; - } - /* TODO: Support struct members and arrays */ - return 0; -} - /* Find a variable in a subprogram die */ static void find_variable(Dwarf_Die *sp_die, struct probe_finder *pf) { int ret; + Dwarf_Die vr_die; + /* TODO: Support struct members and arrays */ if (!is_c_varname(pf->var)) { /* Output raw parameters */ ret = snprintf(pf->buf, pf->len, " %s", pf->var); @@ -379,31 +301,42 @@ static void find_variable(Dwarf_Die *sp_die, struct probe_finder *pf) pr_debug("Searching '%s' variable in context.\n", pf->var); /* Search child die for local variables and parameters. */ - ret = search_die_from_children(sp_die, variable_search_cb, pf); - if (!ret) + if (!die_find_variable(sp_die, pf->var, &vr_die)) die("Failed to find '%s' in this function.", pf->var); + + show_variable(&vr_die, pf); } /* Show a probe point to output buffer */ -static void show_probe_point(Dwarf_Die *sp_die, size_t offs, - struct probe_finder *pf) +static void show_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf) { struct probe_point *pp = pf->pp; + Dwarf_Addr eaddr; + Dwarf_Die die_mem; const char *name; char tmp[MAX_PROBE_BUFFER]; int ret, i, len; Dwarf_Attribute fb_attr; size_t nops; + /* If no real subprogram, find a real one */ + if (!sp_die || dwarf_tag(sp_die) != DW_TAG_subprogram) { + sp_die = die_get_real_subprogram(&pf->cu_die, + pf->addr, &die_mem); + if (!sp_die) + die("Probe point is not found in subprograms."); + } + /* Output name of probe point */ name = dwarf_diename(sp_die); if (name) { - ret = snprintf(tmp, MAX_PROBE_BUFFER, "%s+%u", name, - (unsigned int)offs); + dwarf_entrypc(sp_die, &eaddr); + ret = snprintf(tmp, MAX_PROBE_BUFFER, "%s+%lu", name, + (unsigned long)(pf->addr - eaddr)); /* Copy the function name if possible */ if (!pp->function) { pp->function = strdup(name); - pp->offset = offs; + pp->offset = (size_t)(pf->addr - eaddr); } } else { /* This function has no name. */ @@ -450,10 +383,9 @@ static void find_probe_point_by_line(struct probe_finder *pf) Dwarf_Lines *lines; Dwarf_Line *line; size_t nlines, i; - Dwarf_Addr addr, epc; + Dwarf_Addr addr; int lineno; int ret; - Dwarf_Die *sp_die, die_mem; ret = dwarf_getsrclines(&pf->cu_die, &lines, &nlines); DIE_IF(ret != 0); @@ -474,77 +406,57 @@ static void find_probe_point_by_line(struct probe_finder *pf) (int)i, lineno, (uintmax_t)addr); pf->addr = addr; - sp_die = die_get_real_subprogram(&pf->cu_die, addr, &die_mem); - if (!sp_die) - die("Probe point is not found in subprograms."); - dwarf_entrypc(sp_die, &epc); - show_probe_point(sp_die, (size_t)(addr - epc), pf); + show_probe_point(NULL, pf); /* Continuing, because target line might be inlined. */ } } +static int probe_point_inline_cb(Dwarf_Die *in_die, void *data) +{ + struct probe_finder *pf = (struct probe_finder *)data; + struct probe_point *pp = pf->pp; + + /* Get probe address */ + pf->addr = die_get_entrypc(in_die); + pf->addr += pp->offset; + pr_debug("found inline addr: 0x%jx\n", (uintmax_t)pf->addr); + + show_probe_point(in_die, pf); + return DWARF_CB_OK; +} /* Search function from function name */ -static int probe_point_search_cb(struct die_link *dlink, void *data) +static int probe_point_search_cb(Dwarf_Die *sp_die, void *data) { struct probe_finder *pf = (struct probe_finder *)data; struct probe_point *pp = pf->pp; - struct die_link *lk; - size_t offs; - int tag; - int ret; - tag = dwarf_tag(&dlink->die); - if (tag == DW_TAG_subprogram) { - if (die_compare_name(&dlink->die, pp->function) == 0) { - if (pp->line) { /* Function relative line */ - pf->fname = dwarf_decl_file(&dlink->die); - dwarf_decl_line(&dlink->die, &pf->lno); - pf->lno += pp->line; - find_probe_point_by_line(pf); - return 1; - } - if (dwarf_func_inline(&dlink->die)) { - /* Inlined function, save it. */ - pf->origin = dlink->die.addr; - return 0; /* Continue to search */ - } - /* Get probe address */ - pf->addr = die_get_entrypc(&dlink->die); - pf->addr += pp->offset; - /* TODO: Check the address in this function */ - show_probe_point(&dlink->die, pp->offset, pf); - return 1; /* Exit; no same symbol in this CU. */ - } - } else if (tag == DW_TAG_inlined_subroutine && pf->origin) { - if (die_compare_abstract_origin(&dlink->die, pf->origin)) { - /* Get probe address */ - pf->addr = die_get_entrypc(&dlink->die); - pf->addr += pp->offset; - pr_debug("found inline addr: 0x%jx\n", - (uintmax_t)pf->addr); - /* Inlined function. Get a real subprogram */ - for (lk = dlink->parent; lk != NULL; lk = lk->parent) { - tag = dwarf_tag(&lk->die); - if (tag == DW_TAG_subprogram && - !dwarf_func_inline(&lk->die)) - goto found; - } - die("Failed to find real subprogram."); -found: - /* Get offset from subprogram */ - ret = die_within_subprogram(&lk->die, pf->addr, &offs); - DIE_IF(!ret); - show_probe_point(&lk->die, offs, pf); - /* Continue to search */ - } - } - return 0; + /* Check tag and diename */ + if (dwarf_tag(sp_die) != DW_TAG_subprogram || + die_compare_name(sp_die, pp->function) != 0) + return 0; + + if (pp->line) { /* Function relative line */ + pf->fname = dwarf_decl_file(sp_die); + dwarf_decl_line(sp_die, &pf->lno); + pf->lno += pp->line; + find_probe_point_by_line(pf); + } else if (!dwarf_func_inline(sp_die)) { + /* Real function */ + pf->addr = die_get_entrypc(sp_die); + pf->addr += pp->offset; + /* TODO: Check the address in this function */ + show_probe_point(sp_die, pf); + } else + /* Inlined function: search instances */ + dwarf_func_inline_instances(sp_die, probe_point_inline_cb, pf); + + return 1; /* Exit; no same symbol in this CU. */ } static void find_probe_point_by_func(struct probe_finder *pf) { - search_die_from_children(&pf->cu_die, probe_point_search_cb, pf); + dwarf_getfuncs(&pf->cu_die, probe_point_search_cb, pf, 0); } /* Find a probe point */ @@ -669,27 +581,25 @@ static void find_line_range_by_line(struct line_finder *lf) } /* Search function from function name */ -static int line_range_search_cb(struct die_link *dlink, void *data) +static int line_range_search_cb(Dwarf_Die *sp_die, void *data) { struct line_finder *lf = (struct line_finder *)data; struct line_range *lr = lf->lr; - int tag; int ret; - tag = dwarf_tag(&dlink->die); - if (tag == DW_TAG_subprogram && - die_compare_name(&dlink->die, lr->function) == 0) { + if (dwarf_tag(sp_die) == DW_TAG_subprogram && + die_compare_name(sp_die, lr->function) == 0) { /* Get the address range of this function */ - ret = dwarf_highpc(&dlink->die, &lf->addr_e); + ret = dwarf_highpc(sp_die, &lf->addr_e); if (ret == 0) - ret = dwarf_lowpc(&dlink->die, &lf->addr_s); + ret = dwarf_lowpc(sp_die, &lf->addr_s); if (ret != 0) { lf->addr_s = 0; lf->addr_e = 0; } - lf->fname = dwarf_decl_file(&dlink->die); - dwarf_decl_line(&dlink->die, &lr->offset); + lf->fname = dwarf_decl_file(sp_die); + dwarf_decl_line(sp_die, &lr->offset); pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset); lf->lno_s = lr->offset + lr->start; if (!lr->end) @@ -706,7 +616,7 @@ static int line_range_search_cb(struct die_link *dlink, void *data) static void find_line_range_by_func(struct line_finder *lf) { - search_die_from_children(&lf->cu_die, line_range_search_cb, lf); + dwarf_getfuncs(&lf->cu_die, line_range_search_cb, lf, 0); } int find_line_range(int fd, struct line_range *lr) diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h index 9dd4a88..74525ae 100644 --- a/tools/perf/util/probe-finder.h +++ b/tools/perf/util/probe-finder.h @@ -66,7 +66,6 @@ struct probe_finder { Dwarf_Addr addr; /* Address */ const char *fname; /* File name */ int lno; /* Line number */ - void *origin; /* Inline origin addr */ Dwarf_Die cu_die; /* Current CU */ /* For variable searching */ -- 1.8.2.3