Hello HATAYAMA-san, On Thu, 02 Aug 2012 14:47:14 +0900 (JST) HATAYAMA Daisuke <[email protected]> wrote:
> From: Atsushi Kumagai <[email protected]> > Subject: Re: makedumpfile -g with recent kernels > Date: Thu, 2 Aug 2012 14:12:51 +0900 > > > Hello Stefan, > > > > On Mon, 09 Jul 2012 11:17:13 +0200 > > Stefan Bader <[email protected]> wrote: > > > >> Hi, > >> > >> I am not sure whether this really is the preferred way as I heard the > >> required > >> info now is in vmcore and vmcoreinfo would not be needed anymore. But just > >> to > >> have it produce some output I noticed that it trips again over some member > >> of > >> struct page that moved into some anonymous structure/union combo. > >> There was some code that was quite specific for the page.mapping case > >> (which now > >> seems to be outside again). I changed the code to be more generic. It did > >> fix my > >> _count problem and should also handle the mapping case (though I could not > >> test). > >> So maybe this would be worth adding to the upstream code. > >> > >> -Stefan > >> > >> Please include me in cc's as I am not subscribed to this ml. > > > > Thank you for your nice work! > > > > Hello Kumagai-san, > > I want to see a whole part of Stefan's patch. Could you post it on the > ml? This is the Stefan's patch. Thanks Atsushi Kumagai --- >From cde00fffeddddd1fcffd3085ded0947fdcd159ef Mon Sep 17 00:00:00 2001 From: Stefan Bader <[email protected]> Date: Thu, 5 Jul 2012 18:03:53 +0200 Subject: [PATCH] Generic search into anonymous members in search_member() There was a special case to find page.mapping in case it would be inside an anonymous union.struct. But recent kernel versions also moved page._count into the depths of some unnamed elements. Naturally not the same as page.mapping. So this tries to approach the problem by implementing a generic method of descending into anonymous sub-members. If this finds a member and it is the member offset that is the target of the search, that offset has to be adjusted on the way back out. Signed-off-by: Stefan Bader <[email protected]> --- dwarf_info.c | 117 ++++++++++++++++++-------------------------------------- dwarf_info.h | 1 - makedumpfile.c | 8 ---- makedumpfile.h | 6 --- 4 files changed, 38 insertions(+), 94 deletions(-) diff --git a/dwarf_info.c b/dwarf_info.c index 1429858..583df53 100644 --- a/dwarf_info.c +++ b/dwarf_info.c @@ -64,7 +64,6 @@ is_search_structure(int cmd) if ((cmd == DWARF_INFO_GET_STRUCT_SIZE) || (cmd == DWARF_INFO_GET_MEMBER_OFFSET) || (cmd == DWARF_INFO_GET_MEMBER_TYPE) - || (cmd == DWARF_INFO_GET_MEMBER_OFFSET_IN_UNION) || (cmd == DWARF_INFO_GET_MEMBER_OFFSET_1ST_UNION) || (cmd == DWARF_INFO_GET_MEMBER_ARRAY_LENGTH)) return TRUE; @@ -447,75 +446,40 @@ get_dwarf_base_type(Dwarf_Die *die) return TRUE; } -/* - * Function for searching struct page.union.struct.mapping. - */ static int -__search_mapping(Dwarf_Die *die, long *offset) +is_anonymous_container(Dwarf_Die *die) { - int tag; - const char *name; - Dwarf_Die child, *walker; - - if (dwarf_child(die, &child) != 0) + if (dwarf_diename(die)) return FALSE; - - walker = &child; - do { - tag = dwarf_tag(walker); - name = dwarf_diename(walker); - - if (tag != DW_TAG_member) - continue; - if ((!name) || strcmp(name, dwarf_info.member_name)) - continue; - if (!get_data_member_location(walker, offset)) - continue; + if (dwarf_tag(die) == DW_TAG_union_type) + return TRUE; + if (dwarf_tag(die) == DW_TAG_structure_type) return TRUE; - - } while (!dwarf_siblingof(walker, walker)); - return FALSE; } -/* - * Function for searching struct page.union.struct. - */ -static int -search_mapping(Dwarf_Die *die, long *offset) +static void +adjust_member_offset(Dwarf_Die *die) { - Dwarf_Die child, *walker; - Dwarf_Die die_struct; - - if (dwarf_child(die, &child) != 0) - return FALSE; + long offset; - walker = &child; - - do { - if (dwarf_tag(walker) != DW_TAG_member) - continue; - if (!get_die_type(walker, &die_struct)) - continue; - if (dwarf_tag(&die_struct) != DW_TAG_structure_type) - continue; - if (__search_mapping(&die_struct, offset)) - return TRUE; - } while (!dwarf_siblingof(walker, walker)); - - return FALSE; + if (dwarf_info.member_offset == NOT_FOUND_STRUCTURE) + return; + if (!get_data_member_location(die, &offset)) + return; + dwarf_info.member_offset += offset; } -static void +static int search_member(Dwarf_Die *die) { int tag; - long offset, offset_union; + long offset; const char *name; - Dwarf_Die child, *walker, die_union; + Dwarf_Die child, *walker, die_type; if (dwarf_child(die, &child) != 0) - return; + return FALSE; walker = &child; @@ -526,6 +490,20 @@ search_member(Dwarf_Die *die) if (tag != DW_TAG_member) continue; + /* + * Descend into anonymous members and search for member + * there. + */ + if (!name) { + if (!get_die_type(walker, &die_type)) + continue; + if (is_anonymous_container(&die_type)) + if (search_member(&die_type)) { + adjust_member_offset(walker); + return TRUE; + } + } + switch (dwarf_info.cmd) { case DWARF_INFO_GET_MEMBER_TYPE: if ((!name) || strcmp(name, dwarf_info.member_name)) @@ -535,7 +513,7 @@ search_member(Dwarf_Die *die) */ if (!get_dwarf_base_type(walker)) continue; - return; + return TRUE; case DWARF_INFO_GET_MEMBER_OFFSET: if ((!name) || strcmp(name, dwarf_info.member_name)) continue; @@ -545,29 +523,11 @@ search_member(Dwarf_Die *die) if (!get_data_member_location(walker, &offset)) continue; dwarf_info.member_offset = offset; - return; - case DWARF_INFO_GET_MEMBER_OFFSET_IN_UNION: - if (!get_die_type(walker, &die_union)) - continue; - if (dwarf_tag(&die_union) != DW_TAG_union_type) - continue; - /* - * Search page.mapping in union. - */ - if (!search_mapping(&die_union, &offset_union)) - continue; - - /* - * Get the member offset. - */ - if (!get_data_member_location(walker, &offset)) - continue; - dwarf_info.member_offset = offset + offset_union; - return; + return TRUE; case DWARF_INFO_GET_MEMBER_OFFSET_1ST_UNION: - if (!get_die_type(walker, &die_union)) + if (!get_die_type(walker, &die_type)) continue; - if (dwarf_tag(&die_union) != DW_TAG_union_type) + if (dwarf_tag(&die_type) != DW_TAG_union_type) continue; /* * Get the member offset. @@ -575,7 +535,7 @@ search_member(Dwarf_Die *die) if (!get_data_member_location(walker, &offset)) continue; dwarf_info.member_offset = offset; - return; + return TRUE; case DWARF_INFO_GET_MEMBER_ARRAY_LENGTH: if ((!name) || strcmp(name, dwarf_info.member_name)) continue; @@ -584,14 +544,14 @@ search_member(Dwarf_Die *die) */ if (!get_data_array_length(walker)) continue; - return; + return TRUE; } } while (!dwarf_siblingof(walker, walker)); /* * Return even if not found. */ - return; + return FALSE; } static void @@ -636,7 +596,6 @@ search_structure(Dwarf_Die *die, int *found) break; case DWARF_INFO_GET_MEMBER_TYPE: case DWARF_INFO_GET_MEMBER_OFFSET: - case DWARF_INFO_GET_MEMBER_OFFSET_IN_UNION: case DWARF_INFO_GET_MEMBER_OFFSET_1ST_UNION: case DWARF_INFO_GET_MEMBER_ARRAY_LENGTH: search_member(die); diff --git a/dwarf_info.h b/dwarf_info.h index 1e07484..8d0084d 100644 --- a/dwarf_info.h +++ b/dwarf_info.h @@ -37,7 +37,6 @@ enum { DWARF_INFO_GET_STRUCT_SIZE, DWARF_INFO_GET_MEMBER_OFFSET, - DWARF_INFO_GET_MEMBER_OFFSET_IN_UNION, DWARF_INFO_GET_MEMBER_OFFSET_1ST_UNION, DWARF_INFO_GET_MEMBER_ARRAY_LENGTH, DWARF_INFO_GET_SYMBOL_ARRAY_LENGTH, diff --git a/makedumpfile.c b/makedumpfile.c index d024e95..d32ce55 100644 --- a/makedumpfile.c +++ b/makedumpfile.c @@ -874,17 +874,9 @@ get_structure_info(void) SIZE_INIT(page, "page"); OFFSET_INIT(page.flags, "page", "flags"); OFFSET_INIT(page._count, "page", "_count"); - OFFSET_INIT(page.mapping, "page", "mapping"); --- /* - * On linux-2.6.16 or later, page.mapping is defined - * in anonymous union. - */ - if (OFFSET(page.mapping) == NOT_FOUND_STRUCTURE) - OFFSET_IN_UNION_INIT(page.mapping, "page", "mapping"); - - /* * Some vmlinux(s) don't have debugging information about * page.mapping. Then, makedumpfile assumes that there is * "mapping" next to "private(unsigned long)" in the first diff --git a/makedumpfile.h b/makedumpfile.h index 6f5489d..4bf502f 100644 --- a/makedumpfile.h +++ b/makedumpfile.h @@ -239,12 +239,6 @@ do { \ == FAILED_DWARFINFO) \ return FALSE; \ } while (0) -#define OFFSET_IN_UNION_INIT(X, Y, Z) \ -do { \ - if ((OFFSET(X) = get_member_offset(Y, Z, DWARF_INFO_GET_MEMBER_OFFSET_IN_UNION)) \ - == FAILED_DWARFINFO) \ - return FALSE; \ -} while (0) #define SYMBOL_ARRAY_LENGTH_INIT(X, Y) \ do { \ if ((ARRAY_LENGTH(X) = get_array_length(Y, NULL, DWARF_INFO_GET_SYMBOL_ARRAY_LENGTH)) == FAILED_DWARFINFO) \ -- 1.7.9.5 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
