[RFC] Add support for non-contiguous memory regions

Message ID	CAKdteOaZmkDJVvwGeb=qjh5YayK6cT7oHBQ9w+GhOtU2gdqwTg@mail.gmail.com
State	New
Headers	show Delivered-To: patch@linaro.org Received-SPF: pass (google.com: domain of binutils-return-107760-patch=linaro.org@sourceware.org designates 209.132.180.131 as permitted sender) client-ip=209.132.180.131; DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:mime-version:from:date:message-id:subject:to :content-type; q=dns; s=default; b=Pf94voNVEdFY9ZIEkNUe7rRzSM25U rstjbxP7ERCadl7DQfkXuw5u8M3ILKn9Et5vN00oLOB4ypydOvPb9Fwl8OHIhocu VE7ifgZxcQyWkucJpKgS/tcAFDeti8rfKFhYq4KblDvFL5YU6/SWL57fSVNVPiBE vw0JlAXOCrDcLU= Mailing-List: contact binutils-help@sourceware.org; run by ezmlm Precedence: bulk Sender: binutils-owner@sourceware.org MIME-Version: 1.0 From: Christophe Lyon <christophe.lyon@linaro.org> Date: Fri, 29 Nov 2019 11:12:03 +0100 Message-ID: <CAKdteOaZmkDJVvwGeb=qjh5YayK6cT7oHBQ9w+GhOtU2gdqwTg@mail.gmail.com> Subject: [PATCH RFC] Add support for non-contiguous memory regions To: binutils <binutils@sourceware.org> Content-Type: multipart/mixed; boundary="000000000000c6d6c30598797659"
Series	[RFC] Add support for non-contiguous memory regions \| expand [RFC] Add support for non-contiguous memory regions

From 5a6274a0db009b7e19835a0726c88360d9b9c6e8 Mon Sep 17 00:00:00 2001 From: Christophe Lyon <christophe.lyon@linaro.org> Date: Mon, 25 Nov 2019 08:55:37 +0000 Subject: [PATCH 1/2] Add support for non-contiguous memory 2019-11-27 Christophe Lyon <christophe.lyon@linaro.org> bfd/ * bfd-in2.h: Regenerate. * section.c (asection): Add already_assigned field. (BFD_FAKE_SECTION): Add default initializer for it. include/ * bfdlink.h (bfd_link_info): Add non_contiguous_regions field. ld/ * ldlang.c (lang_add_section): Add support for non_contiguous_regions. (size_input_section): Likewise. (lang_size_sections_1): Likewise. * ldlex.h (option_values): Add OPTION_NON_CONTIGUOUS_REGIONS. * lexsup.c (ld_options): Add entry for --enable-non-contiguous-regions. (parse_args): Handle it. --- bfd/bfd-in2.h | 9 +++++++- bfd/section.c | 9 +++++++- include/bfdlink.h | 3 +++ ld/ldlang.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++--- ld/ldlex.h | 1 + ld/lexsup.c | 5 +++++ 6 files changed, 89 insertions(+), 5 deletions(-) diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h index a00dfa35..0e1126c 100644 --- a/bfd/bfd-in2.h +++ b/bfd/bfd-in2.h @@ -1177,6 +1177,10 @@ typedef struct bfd_section struct bfd_link_order *link_order; struct bfd_section *s; } map_head, map_tail; + /* Points to the output section this section is already assigned to, if any. + This is used when support for non-contiguous memory regions is enabled. */ + struct bfd_section *already_assigned; + } asection; /* Relax table contains information about instructions which can @@ -1358,7 +1362,10 @@ discarded_section (const asection *sec) (struct bfd_symbol *) SYM, &SEC.symbol, \ \ /* map_head, map_tail */ \ - { NULL }, { NULL } \ + { NULL }, { NULL }, \ + \ + /* already_assigned */ \ + NULL \ } /* We use a macro to initialize the static asymbol structures because diff --git a/bfd/section.c b/bfd/section.c index 34e08ae..b1f0b71 100644 --- a/bfd/section.c +++ b/bfd/section.c @@ -536,6 +536,10 @@ CODE_FRAGMENT . struct bfd_link_order *link_order; . struct bfd_section *s; . } map_head, map_tail; +. {* Points to the output section this section is already assigned to, if any. +. This is used when support for non-contiguous memory regions is enabled. *} +. struct bfd_section *already_assigned; +. .} asection; . .{* Relax table contains information about instructions which can @@ -717,7 +721,10 @@ CODE_FRAGMENT . (struct bfd_symbol *) SYM, &SEC.symbol, \ . \ . {* map_head, map_tail *} \ -. { NULL }, { NULL } \ +. { NULL }, { NULL }, \ +. \ +. {* already_assigned *} \ +. NULL \ . } . .{* We use a macro to initialize the static asymbol structures because diff --git a/include/bfdlink.h b/include/bfdlink.h index 32d1512..e1e7c1e 100644 --- a/include/bfdlink.h +++ b/include/bfdlink.h @@ -501,6 +501,9 @@ struct bfd_link_info /* TRUE if "-Map map" is passed to linker. */ unsigned int has_map_file : 1; + /* TRUE if "--enable-non-contiguous-regions" is passed to the linker. */ + unsigned int non_contiguous_regions : 1; + /* Char that may appear as the first char of a symbol, but should be skipped (like symbol_leading_char) when looking up symbols in wrap_hash. Used by PowerPC Linux for 'dot' symbols. */ diff --git a/ld/ldlang.c b/ld/ldlang.c index eedcb7f..f2acdbb 100644 --- a/ld/ldlang.c +++ b/ld/ldlang.c @@ -2550,7 +2550,14 @@ lang_add_section (lang_statement_list_type *ptr, } if (section->output_section != NULL) - return; + { + if (!link_info.non_contiguous_regions) + return; + /* SECTION has already been affected to an output section, but + the user allows it to be mapped to another one in case it + overflows. We'll later update the actual output section in + size_input_section as appropriate. */ + } /* We don't copy the SEC_NEVER_LOAD flag from an input section to an output section, because we want to be able to include a @@ -5109,11 +5116,27 @@ size_input_section (lang_statement_union_type **this_ptr, lang_output_section_statement_type *output_section_statement, fill_type *fill, + bfd_boolean *removed, bfd_vma dot) { lang_input_section_type *is = &((*this_ptr)->input_section); asection *i = is->section; asection *o = output_section_statement->bfd_section; + *removed = 0; + + if (link_info.non_contiguous_regions) + { + /* If the input section I has already been successfully assigned + to an output section other than O, don't bother with it and + let the caller remove it from the list. Keep processing in + case we have already handled O, because the repeated passes + have reinitialized its size. */ + if (i->already_assigned && i->already_assigned != o) + { + *removed = 1; + return dot; + } + } if (i->sec_info_type == SEC_INFO_TYPE_JUST_SYMS) i->output_offset = i->vma - o->vma; @@ -5145,6 +5168,24 @@ size_input_section dot += alignment_needed; } + if (link_info.non_contiguous_regions) + { + /* If I would overflow O, let the caller remove I from the + list. */ + if (output_section_statement->region) + { + bfd_vma end = output_section_statement->region->origin + + output_section_statement->region->length; + + if (dot + TO_ADDR (i->size) > end) + { + *removed = 1; + dot = end; + return dot; + } + } + } + /* Remember where in the output section this input section goes. */ i->output_offset = dot - o->vma; @@ -5152,6 +5193,14 @@ size_input_section dot += TO_ADDR (i->size); if (!(o->flags & SEC_FIXED_SIZE)) o->size = TO_SIZE (dot - o->vma); + + if (link_info.non_contiguous_regions) + { + /* Record that I was successfully assigned to O, and update + its actual output section too. */ + i->already_assigned = o; + i->output_section = o; + } } return dot; @@ -5436,9 +5485,10 @@ lang_size_sections_1 bfd_boolean check_regions) { lang_statement_union_type *s; + lang_statement_union_type *prev_s = NULL; /* Size up the sections from their constituent parts. */ - for (s = *prev; s != NULL; s = s->header.next) + for (s = *prev; s != NULL; prev_s = s, s = s->header.next) { switch (s->header.type) { @@ -5852,6 +5902,7 @@ lang_size_sections_1 case lang_input_section_enum: { asection *i; + bfd_boolean removed; i = s->input_section.section; if (relax) @@ -5864,7 +5915,17 @@ lang_size_sections_1 *relax = TRUE; } dot = size_input_section (prev, output_section_statement, - fill, dot); + fill, &removed, dot); + + if (link_info.non_contiguous_regions && removed) + { + /* If I doesn't fit in the current output section, + remove it from the list. */ + if (prev_s) + prev_s->header.next=s->header.next; + else + *prev = s->header.next; + } } break; diff --git a/ld/ldlex.h b/ld/ldlex.h index 32a7a64..4e7a419 100644 --- a/ld/ldlex.h +++ b/ld/ldlex.h @@ -150,6 +150,7 @@ enum option_values OPTION_FORCE_GROUP_ALLOCATION, OPTION_PRINT_MAP_DISCARDED, OPTION_NO_PRINT_MAP_DISCARDED, + OPTION_NON_CONTIGUOUS_REGIONS, }; /* The initial parser states. */ diff --git a/ld/lexsup.c b/ld/lexsup.c index d7766c3..13cab6d 100644 --- a/ld/lexsup.c +++ b/ld/lexsup.c @@ -122,6 +122,8 @@ static const struct ld_option ld_options[] = 'E', NULL, N_("Export all dynamic symbols"), TWO_DASHES }, { {"no-export-dynamic", no_argument, NULL, OPTION_NO_EXPORT_DYNAMIC}, '\0', NULL, N_("Undo the effect of --export-dynamic"), TWO_DASHES }, + { {"enable-non-contiguous-regions", no_argument, NULL, OPTION_NON_CONTIGUOUS_REGIONS}, + '\0', NULL, N_("Enable support of non-contiguous memory regions"), TWO_DASHES }, { {"EB", no_argument, NULL, OPTION_EB}, '\0', NULL, N_("Link big-endian objects"), ONE_DASH }, { {"EL", no_argument, NULL, OPTION_EL}, @@ -845,6 +847,9 @@ parse_args (unsigned argc, char **argv) case OPTION_NO_EXPORT_DYNAMIC: link_info.export_dynamic = FALSE; break; + case OPTION_NON_CONTIGUOUS_REGIONS: + link_info.non_contiguous_regions = TRUE; + break; case 'e': lang_add_entry (optarg, TRUE); break; -- 2.7.4

[RFC] Add support for non-contiguous memory regions

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