* [PATCH 0/2] objtool: clang-related fixes
@ 2020-02-18 3:41 Josh Poimboeuf
2020-02-18 3:41 ` [PATCH 1/2] objtool: Fix clang switch table edge case Josh Poimboeuf
` (2 more replies)
0 siblings, 3 replies; 10+ messages in thread
From: Josh Poimboeuf @ 2020-02-18 3:41 UTC (permalink / raw)
To: x86; +Cc: linux-kernel, Peter Zijlstra, Nick Desaulniers
Fix a couple of issues which were discovered after clang CI was broken
by 644592d32837 ("objtool: Fail the kernel build on fatal errors").
Josh Poimboeuf (2):
objtool: Fix clang switch table edge case
objtool: Improve call destination function detection
tools/objtool/check.c | 38 +++++++++++++++++++++++++++-----------
tools/objtool/elf.c | 14 ++++++++++++--
tools/objtool/elf.h | 1 +
3 files changed, 40 insertions(+), 13 deletions(-)
--
2.21.1
^ permalink raw reply [flat|nested] 10+ messages in thread* [PATCH 1/2] objtool: Fix clang switch table edge case 2020-02-18 3:41 [PATCH 0/2] objtool: clang-related fixes Josh Poimboeuf @ 2020-02-18 3:41 ` Josh Poimboeuf 2020-02-18 19:57 ` Nathan Chancellor 2020-02-21 9:50 ` [tip: core/objtool] " tip-bot2 for Josh Poimboeuf 2020-02-18 3:41 ` [PATCH 2/2] objtool: Improve call destination function detection Josh Poimboeuf 2020-02-20 19:06 ` [PATCH 0/2] objtool: clang-related fixes Nick Desaulniers 2 siblings, 2 replies; 10+ messages in thread From: Josh Poimboeuf @ 2020-02-18 3:41 UTC (permalink / raw) To: x86; +Cc: linux-kernel, Peter Zijlstra, Nick Desaulniers Clang has the ability to create a switch table which is not a jump table, but is rather a table of string pointers. This confuses objtool, because it sees the relocations for the string pointers and assumes they're part of a jump table: drivers/ata/sata_dwc_460ex.o: warning: objtool: sata_dwc_bmdma_start_by_tag()+0x3a2: can't find switch jump table net/ceph/messenger.o: warning: objtool: ceph_con_workfn()+0x47c: can't find switch jump table Make objtool's find_jump_table() smart enough to distinguish between a switch jump table (which has relocations to text addresses in the same function as the original instruction) and other anonymous rodata (which may have relocations to elsewhere). Link: https://github.com/ClangBuiltLinux/linux/issues/485 Reported-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> --- tools/objtool/check.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index b6da413bcbd6..e7227649bac7 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1019,7 +1019,7 @@ static struct rela *find_jump_table(struct objtool_file *file, struct instruction *insn) { struct rela *text_rela, *table_rela; - struct instruction *orig_insn = insn; + struct instruction *dest_insn, *orig_insn = insn; struct section *table_sec; unsigned long table_offset; @@ -1071,10 +1071,17 @@ static struct rela *find_jump_table(struct objtool_file *file, strcmp(table_sec->name, C_JUMP_TABLE_SECTION)) continue; - /* Each table entry has a rela associated with it. */ + /* + * Each table entry has a rela associated with it. The rela + * should reference text in the same function as the original + * instruction. + */ table_rela = find_rela_by_dest(table_sec, table_offset); if (!table_rela) continue; + dest_insn = find_insn(file, table_rela->sym->sec, table_rela->addend); + if (!dest_insn || !dest_insn->func || dest_insn->func->pfunc != func) + continue; /* * Use of RIP-relative switch jumps is quite rare, and -- 2.21.1 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH 1/2] objtool: Fix clang switch table edge case 2020-02-18 3:41 ` [PATCH 1/2] objtool: Fix clang switch table edge case Josh Poimboeuf @ 2020-02-18 19:57 ` Nathan Chancellor 2020-02-21 9:50 ` [tip: core/objtool] " tip-bot2 for Josh Poimboeuf 1 sibling, 0 replies; 10+ messages in thread From: Nathan Chancellor @ 2020-02-18 19:57 UTC (permalink / raw) To: Josh Poimboeuf; +Cc: x86, linux-kernel, Peter Zijlstra, Nick Desaulniers On Mon, Feb 17, 2020 at 09:41:53PM -0600, Josh Poimboeuf wrote: > Clang has the ability to create a switch table which is not a jump > table, but is rather a table of string pointers. This confuses objtool, > because it sees the relocations for the string pointers and assumes > they're part of a jump table: > > drivers/ata/sata_dwc_460ex.o: warning: objtool: sata_dwc_bmdma_start_by_tag()+0x3a2: can't find switch jump table > net/ceph/messenger.o: warning: objtool: ceph_con_workfn()+0x47c: can't find switch jump table > > Make objtool's find_jump_table() smart enough to distinguish between a > switch jump table (which has relocations to text addresses in the same > function as the original instruction) and other anonymous rodata (which > may have relocations to elsewhere). > > Link: https://github.com/ClangBuiltLinux/linux/issues/485 > Reported-by: Nick Desaulniers <ndesaulniers@google.com> > Tested-by: Nick Desaulniers <ndesaulniers@google.com> > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Tested with clang-11 and binutils 2.34, a combo that was previously broken and I no longer see these warnings on either defconfig or allyesconfig. Tested-by: Nathan Chancellor <natechancellor@gmail.com> ^ permalink raw reply [flat|nested] 10+ messages in thread
* [tip: core/objtool] objtool: Fix clang switch table edge case 2020-02-18 3:41 ` [PATCH 1/2] objtool: Fix clang switch table edge case Josh Poimboeuf 2020-02-18 19:57 ` Nathan Chancellor @ 2020-02-21 9:50 ` tip-bot2 for Josh Poimboeuf 1 sibling, 0 replies; 10+ messages in thread From: tip-bot2 for Josh Poimboeuf @ 2020-02-21 9:50 UTC (permalink / raw) To: linux-tip-commits Cc: Nick Desaulniers, Josh Poimboeuf, Borislav Petkov, Nathan Chancellor, x86, LKML The following commit has been merged into the core/objtool branch of tip: Commit-ID: 113d4bc9048336ba7c3d2ad972dbad4aef6e148a Gitweb: https://git.kernel.org/tip/113d4bc9048336ba7c3d2ad972dbad4aef6e148a Author: Josh Poimboeuf <jpoimboe@redhat.com> AuthorDate: Mon, 17 Feb 2020 21:41:53 -06:00 Committer: Borislav Petkov <bp@suse.de> CommitterDate: Fri, 21 Feb 2020 10:12:52 +01:00 objtool: Fix clang switch table edge case Clang has the ability to create a switch table which is not a jump table, but is rather a table of string pointers. This confuses objtool, because it sees the relocations for the string pointers and assumes they're part of a jump table: drivers/ata/sata_dwc_460ex.o: warning: objtool: sata_dwc_bmdma_start_by_tag()+0x3a2: can't find switch jump table net/ceph/messenger.o: warning: objtool: ceph_con_workfn()+0x47c: can't find switch jump table Make objtool's find_jump_table() smart enough to distinguish between a switch jump table (which has relocations to text addresses in the same function as the original instruction) and other anonymous rodata (which may have relocations to elsewhere). Reported-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://github.com/ClangBuiltLinux/linux/issues/485 Link: https://lkml.kernel.org/r/263f6aae46d33da0b86d7030ced878cb5cab1788.1581997059.git.jpoimboe@redhat.com --- tools/objtool/check.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index b038de2..4d6e283 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1025,7 +1025,7 @@ static struct rela *find_jump_table(struct objtool_file *file, struct instruction *insn) { struct rela *text_rela, *table_rela; - struct instruction *orig_insn = insn; + struct instruction *dest_insn, *orig_insn = insn; struct section *table_sec; unsigned long table_offset; @@ -1077,10 +1077,17 @@ static struct rela *find_jump_table(struct objtool_file *file, strcmp(table_sec->name, C_JUMP_TABLE_SECTION)) continue; - /* Each table entry has a rela associated with it. */ + /* + * Each table entry has a rela associated with it. The rela + * should reference text in the same function as the original + * instruction. + */ table_rela = find_rela_by_dest(table_sec, table_offset); if (!table_rela) continue; + dest_insn = find_insn(file, table_rela->sym->sec, table_rela->addend); + if (!dest_insn || !dest_insn->func || dest_insn->func->pfunc != func) + continue; /* * Use of RIP-relative switch jumps is quite rare, and ^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH 2/2] objtool: Improve call destination function detection 2020-02-18 3:41 [PATCH 0/2] objtool: clang-related fixes Josh Poimboeuf 2020-02-18 3:41 ` [PATCH 1/2] objtool: Fix clang switch table edge case Josh Poimboeuf @ 2020-02-18 3:41 ` Josh Poimboeuf 2020-02-18 18:13 ` Nick Desaulniers ` (2 more replies) 2020-02-20 19:06 ` [PATCH 0/2] objtool: clang-related fixes Nick Desaulniers 2 siblings, 3 replies; 10+ messages in thread From: Josh Poimboeuf @ 2020-02-18 3:41 UTC (permalink / raw) To: x86; +Cc: linux-kernel, Peter Zijlstra, Nick Desaulniers A recent clang change, combined with a binutils bug, can trigger a situation where a ".Lprintk$local" STT_NOTYPE symbol gets created at the same offset as the "printk" STT_FUNC symbol. This confuses objtool: kernel/printk/printk.o: warning: objtool: ignore_loglevel_setup()+0x10: can't find call dest symbol at .text+0xc67 Improve the call destination detection by looking specifically for an STT_FUNC symbol. Link: https://github.com/ClangBuiltLinux/linux/issues/872 Link: https://sourceware.org/bugzilla/show_bug.cgi?id=25551 Reported-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> --- tools/objtool/check.c | 27 ++++++++++++++++++--------- tools/objtool/elf.c | 14 ++++++++++++-- tools/objtool/elf.h | 1 + 3 files changed, 31 insertions(+), 11 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index e7227649bac7..da0767128f61 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -415,8 +415,8 @@ static void add_ignores(struct objtool_file *file) break; case STT_SECTION: - func = find_symbol_by_offset(rela->sym->sec, rela->addend); - if (!func || func->type != STT_FUNC) + func = find_func_by_offset(rela->sym->sec, rela->addend); + if (!func) continue; break; @@ -679,10 +679,14 @@ static int add_call_destinations(struct objtool_file *file) insn->len); if (!rela) { dest_off = insn->offset + insn->len + insn->immediate; - insn->call_dest = find_symbol_by_offset(insn->sec, - dest_off); + insn->call_dest = find_func_by_offset(insn->sec, dest_off); + if (!insn->call_dest) + insn->call_dest = find_symbol_by_offset(insn->sec, dest_off); - if (!insn->call_dest && !insn->ignore) { + if (insn->ignore) + continue; + + if (!insn->call_dest) { WARN_FUNC("unsupported intra-function call", insn->sec, insn->offset); if (retpoline) @@ -690,11 +694,16 @@ static int add_call_destinations(struct objtool_file *file) return -1; } + if (insn->func && insn->call_dest->type != STT_FUNC) { + WARN_FUNC("unsupported call to non-function", + insn->sec, insn->offset); + return -1; + } + } else if (rela->sym->type == STT_SECTION) { - insn->call_dest = find_symbol_by_offset(rela->sym->sec, - rela->addend+4); - if (!insn->call_dest || - insn->call_dest->type != STT_FUNC) { + insn->call_dest = find_func_by_offset(rela->sym->sec, + rela->addend+4); + if (!insn->call_dest) { WARN_FUNC("can't find call dest symbol at %s+0x%x", insn->sec, insn->offset, rela->sym->sec->name, diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index edba4745f25a..cc4601c879ce 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -62,8 +62,18 @@ struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset) struct symbol *sym; list_for_each_entry(sym, &sec->symbol_list, list) - if (sym->type != STT_SECTION && - sym->offset == offset) + if (sym->type != STT_SECTION && sym->offset == offset) + return sym; + + return NULL; +} + +struct symbol *find_func_by_offset(struct section *sec, unsigned long offset) +{ + struct symbol *sym; + + list_for_each_entry(sym, &sec->symbol_list, list) + if (sym->type == STT_FUNC && sym->offset == offset) return sym; return NULL; diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h index 44150204db4d..a1963259b930 100644 --- a/tools/objtool/elf.h +++ b/tools/objtool/elf.h @@ -77,6 +77,7 @@ struct elf { struct elf *elf_read(const char *name, int flags); struct section *find_section_by_name(struct elf *elf, const char *name); +struct symbol *find_func_by_offset(struct section *sec, unsigned long offset); struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset); struct symbol *find_symbol_by_name(struct elf *elf, const char *name); struct symbol *find_symbol_containing(struct section *sec, unsigned long offset); -- 2.21.1 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH 2/2] objtool: Improve call destination function detection 2020-02-18 3:41 ` [PATCH 2/2] objtool: Improve call destination function detection Josh Poimboeuf @ 2020-02-18 18:13 ` Nick Desaulniers 2020-02-18 19:58 ` Nathan Chancellor 2020-02-21 9:50 ` [tip: core/objtool] " tip-bot2 for Josh Poimboeuf 2 siblings, 0 replies; 10+ messages in thread From: Nick Desaulniers @ 2020-02-18 18:13 UTC (permalink / raw) To: Josh Poimboeuf Cc: maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT), LKML, Peter Zijlstra On Mon, Feb 17, 2020 at 7:42 PM Josh Poimboeuf <jpoimboe@redhat.com> wrote: > > A recent clang change, combined with a binutils bug, can trigger a > situation where a ".Lprintk$local" STT_NOTYPE symbol gets created at the > same offset as the "printk" STT_FUNC symbol. This confuses objtool: > > kernel/printk/printk.o: warning: objtool: ignore_loglevel_setup()+0x10: can't find call dest symbol at .text+0xc67 > > Improve the call destination detection by looking specifically for an > STT_FUNC symbol. > > Link: https://github.com/ClangBuiltLinux/linux/issues/872 > Link: https://sourceware.org/bugzilla/show_bug.cgi?id=25551 > Reported-by: Nick Desaulniers <ndesaulniers@google.com> > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Thanks Josh. Tested-by: Nick Desaulniers <ndesaulniers@google.com> Tested defconfig and allyesconfig builds with the series. > --- > tools/objtool/check.c | 27 ++++++++++++++++++--------- > tools/objtool/elf.c | 14 ++++++++++++-- > tools/objtool/elf.h | 1 + > 3 files changed, 31 insertions(+), 11 deletions(-) > > diff --git a/tools/objtool/check.c b/tools/objtool/check.c > index e7227649bac7..da0767128f61 100644 > --- a/tools/objtool/check.c > +++ b/tools/objtool/check.c > @@ -415,8 +415,8 @@ static void add_ignores(struct objtool_file *file) > break; > > case STT_SECTION: > - func = find_symbol_by_offset(rela->sym->sec, rela->addend); > - if (!func || func->type != STT_FUNC) > + func = find_func_by_offset(rela->sym->sec, rela->addend); > + if (!func) > continue; > break; > > @@ -679,10 +679,14 @@ static int add_call_destinations(struct objtool_file *file) > insn->len); > if (!rela) { > dest_off = insn->offset + insn->len + insn->immediate; > - insn->call_dest = find_symbol_by_offset(insn->sec, > - dest_off); > + insn->call_dest = find_func_by_offset(insn->sec, dest_off); > + if (!insn->call_dest) > + insn->call_dest = find_symbol_by_offset(insn->sec, dest_off); > > - if (!insn->call_dest && !insn->ignore) { > + if (insn->ignore) > + continue; > + > + if (!insn->call_dest) { > WARN_FUNC("unsupported intra-function call", > insn->sec, insn->offset); > if (retpoline) > @@ -690,11 +694,16 @@ static int add_call_destinations(struct objtool_file *file) > return -1; > } > > + if (insn->func && insn->call_dest->type != STT_FUNC) { > + WARN_FUNC("unsupported call to non-function", > + insn->sec, insn->offset); > + return -1; > + } > + > } else if (rela->sym->type == STT_SECTION) { > - insn->call_dest = find_symbol_by_offset(rela->sym->sec, > - rela->addend+4); > - if (!insn->call_dest || > - insn->call_dest->type != STT_FUNC) { > + insn->call_dest = find_func_by_offset(rela->sym->sec, > + rela->addend+4); > + if (!insn->call_dest) { > WARN_FUNC("can't find call dest symbol at %s+0x%x", > insn->sec, insn->offset, > rela->sym->sec->name, > diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c > index edba4745f25a..cc4601c879ce 100644 > --- a/tools/objtool/elf.c > +++ b/tools/objtool/elf.c > @@ -62,8 +62,18 @@ struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset) > struct symbol *sym; > > list_for_each_entry(sym, &sec->symbol_list, list) > - if (sym->type != STT_SECTION && > - sym->offset == offset) > + if (sym->type != STT_SECTION && sym->offset == offset) > + return sym; > + > + return NULL; > +} > + > +struct symbol *find_func_by_offset(struct section *sec, unsigned long offset) > +{ > + struct symbol *sym; > + > + list_for_each_entry(sym, &sec->symbol_list, list) > + if (sym->type == STT_FUNC && sym->offset == offset) > return sym; > > return NULL; > diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h > index 44150204db4d..a1963259b930 100644 > --- a/tools/objtool/elf.h > +++ b/tools/objtool/elf.h > @@ -77,6 +77,7 @@ struct elf { > > struct elf *elf_read(const char *name, int flags); > struct section *find_section_by_name(struct elf *elf, const char *name); > +struct symbol *find_func_by_offset(struct section *sec, unsigned long offset); > struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset); > struct symbol *find_symbol_by_name(struct elf *elf, const char *name); > struct symbol *find_symbol_containing(struct section *sec, unsigned long offset); > -- > 2.21.1 > -- Thanks, ~Nick Desaulniers ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 2/2] objtool: Improve call destination function detection 2020-02-18 3:41 ` [PATCH 2/2] objtool: Improve call destination function detection Josh Poimboeuf 2020-02-18 18:13 ` Nick Desaulniers @ 2020-02-18 19:58 ` Nathan Chancellor 2020-02-21 9:50 ` [tip: core/objtool] " tip-bot2 for Josh Poimboeuf 2 siblings, 0 replies; 10+ messages in thread From: Nathan Chancellor @ 2020-02-18 19:58 UTC (permalink / raw) To: Josh Poimboeuf; +Cc: x86, linux-kernel, Peter Zijlstra, Nick Desaulniers On Mon, Feb 17, 2020 at 09:41:54PM -0600, Josh Poimboeuf wrote: > A recent clang change, combined with a binutils bug, can trigger a > situation where a ".Lprintk$local" STT_NOTYPE symbol gets created at the > same offset as the "printk" STT_FUNC symbol. This confuses objtool: > > kernel/printk/printk.o: warning: objtool: ignore_loglevel_setup()+0x10: can't find call dest symbol at .text+0xc67 > > Improve the call destination detection by looking specifically for an > STT_FUNC symbol. > > Link: https://github.com/ClangBuiltLinux/linux/issues/872 > Link: https://sourceware.org/bugzilla/show_bug.cgi?id=25551 > Reported-by: Nick Desaulniers <ndesaulniers@google.com> > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Tested with clang-11 and binutils 2.34, a combo that was previously broken and I no longer see these warnings on either defconfig or allyesconfig. Tested-by: Nathan Chancellor <natechancellor@gmail.com> ^ permalink raw reply [flat|nested] 10+ messages in thread
* [tip: core/objtool] objtool: Improve call destination function detection 2020-02-18 3:41 ` [PATCH 2/2] objtool: Improve call destination function detection Josh Poimboeuf 2020-02-18 18:13 ` Nick Desaulniers 2020-02-18 19:58 ` Nathan Chancellor @ 2020-02-21 9:50 ` tip-bot2 for Josh Poimboeuf 2 siblings, 0 replies; 10+ messages in thread From: tip-bot2 for Josh Poimboeuf @ 2020-02-21 9:50 UTC (permalink / raw) To: linux-tip-commits Cc: Nick Desaulniers, Josh Poimboeuf, Borislav Petkov, Nathan Chancellor, x86, LKML The following commit has been merged into the core/objtool branch of tip: Commit-ID: 7acfe5315312fc56c2a94c9216448087b38ae909 Gitweb: https://git.kernel.org/tip/7acfe5315312fc56c2a94c9216448087b38ae909 Author: Josh Poimboeuf <jpoimboe@redhat.com> AuthorDate: Mon, 17 Feb 2020 21:41:54 -06:00 Committer: Borislav Petkov <bp@suse.de> CommitterDate: Fri, 21 Feb 2020 10:20:34 +01:00 objtool: Improve call destination function detection A recent clang change, combined with a binutils bug, can trigger a situation where a ".Lprintk$local" STT_NOTYPE symbol gets created at the same offset as the "printk" STT_FUNC symbol. This confuses objtool: kernel/printk/printk.o: warning: objtool: ignore_loglevel_setup()+0x10: can't find call dest symbol at .text+0xc67 Improve the call destination detection by looking specifically for an STT_FUNC symbol. Reported-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://github.com/ClangBuiltLinux/linux/issues/872 Link: https://sourceware.org/bugzilla/show_bug.cgi?id=25551 Link: https://lkml.kernel.org/r/0a7ee320bc0ea4469bd3dc450a7b4725669e0ea9.1581997059.git.jpoimboe@redhat.com --- tools/objtool/check.c | 27 ++++++++++++++++++--------- tools/objtool/elf.c | 14 ++++++++++++-- tools/objtool/elf.h | 1 + 3 files changed, 31 insertions(+), 11 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 4d6e283..6b6178e 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -420,8 +420,8 @@ static void add_ignores(struct objtool_file *file) break; case STT_SECTION: - func = find_symbol_by_offset(rela->sym->sec, rela->addend); - if (!func || func->type != STT_FUNC) + func = find_func_by_offset(rela->sym->sec, rela->addend); + if (!func) continue; break; @@ -665,10 +665,14 @@ static int add_call_destinations(struct objtool_file *file) insn->len); if (!rela) { dest_off = insn->offset + insn->len + insn->immediate; - insn->call_dest = find_symbol_by_offset(insn->sec, - dest_off); + insn->call_dest = find_func_by_offset(insn->sec, dest_off); + if (!insn->call_dest) + insn->call_dest = find_symbol_by_offset(insn->sec, dest_off); - if (!insn->call_dest && !insn->ignore) { + if (insn->ignore) + continue; + + if (!insn->call_dest) { WARN_FUNC("unsupported intra-function call", insn->sec, insn->offset); if (retpoline) @@ -676,11 +680,16 @@ static int add_call_destinations(struct objtool_file *file) return -1; } + if (insn->func && insn->call_dest->type != STT_FUNC) { + WARN_FUNC("unsupported call to non-function", + insn->sec, insn->offset); + return -1; + } + } else if (rela->sym->type == STT_SECTION) { - insn->call_dest = find_symbol_by_offset(rela->sym->sec, - rela->addend+4); - if (!insn->call_dest || - insn->call_dest->type != STT_FUNC) { + insn->call_dest = find_func_by_offset(rela->sym->sec, + rela->addend+4); + if (!insn->call_dest) { WARN_FUNC("can't find call dest symbol at %s+0x%x", insn->sec, insn->offset, rela->sym->sec->name, diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index edba474..cc4601c 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -62,8 +62,18 @@ struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset) struct symbol *sym; list_for_each_entry(sym, &sec->symbol_list, list) - if (sym->type != STT_SECTION && - sym->offset == offset) + if (sym->type != STT_SECTION && sym->offset == offset) + return sym; + + return NULL; +} + +struct symbol *find_func_by_offset(struct section *sec, unsigned long offset) +{ + struct symbol *sym; + + list_for_each_entry(sym, &sec->symbol_list, list) + if (sym->type == STT_FUNC && sym->offset == offset) return sym; return NULL; diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h index 4415020..a196325 100644 --- a/tools/objtool/elf.h +++ b/tools/objtool/elf.h @@ -77,6 +77,7 @@ struct elf { struct elf *elf_read(const char *name, int flags); struct section *find_section_by_name(struct elf *elf, const char *name); +struct symbol *find_func_by_offset(struct section *sec, unsigned long offset); struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset); struct symbol *find_symbol_by_name(struct elf *elf, const char *name); struct symbol *find_symbol_containing(struct section *sec, unsigned long offset); ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH 0/2] objtool: clang-related fixes 2020-02-18 3:41 [PATCH 0/2] objtool: clang-related fixes Josh Poimboeuf 2020-02-18 3:41 ` [PATCH 1/2] objtool: Fix clang switch table edge case Josh Poimboeuf 2020-02-18 3:41 ` [PATCH 2/2] objtool: Improve call destination function detection Josh Poimboeuf @ 2020-02-20 19:06 ` Nick Desaulniers 2020-02-20 19:27 ` Borislav Petkov 2 siblings, 1 reply; 10+ messages in thread From: Nick Desaulniers @ 2020-02-20 19:06 UTC (permalink / raw) To: Thomas Gleixner, Ingo Molnar, Borislav Petkov Cc: maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT), LKML, Peter Zijlstra, Josh Poimboeuf Hello, can one of the x86 maintainers please pick up this series? Our CI has been red *for days* now without it. On Mon, Feb 17, 2020 at 7:42 PM Josh Poimboeuf <jpoimboe@redhat.com> wrote: > > Fix a couple of issues which were discovered after clang CI was broken > by 644592d32837 ("objtool: Fail the kernel build on fatal errors"). > > Josh Poimboeuf (2): > objtool: Fix clang switch table edge case > objtool: Improve call destination function detection > > tools/objtool/check.c | 38 +++++++++++++++++++++++++++----------- > tools/objtool/elf.c | 14 ++++++++++++-- > tools/objtool/elf.h | 1 + > 3 files changed, 40 insertions(+), 13 deletions(-) > > -- > 2.21.1 > -- Thanks, ~Nick Desaulniers ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 0/2] objtool: clang-related fixes 2020-02-20 19:06 ` [PATCH 0/2] objtool: clang-related fixes Nick Desaulniers @ 2020-02-20 19:27 ` Borislav Petkov 0 siblings, 0 replies; 10+ messages in thread From: Borislav Petkov @ 2020-02-20 19:27 UTC (permalink / raw) To: Nick Desaulniers Cc: Thomas Gleixner, Ingo Molnar, maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT), LKML, Peter Zijlstra, Josh Poimboeuf On Thu, Feb 20, 2020 at 11:06:30AM -0800, Nick Desaulniers wrote: > Hello, can one of the x86 maintainers please pick up this series? Our > CI has been red *for days* now without it. I'll queue them tomorrow. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2020-02-21 9:51 UTC | newest] Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-02-18 3:41 [PATCH 0/2] objtool: clang-related fixes Josh Poimboeuf 2020-02-18 3:41 ` [PATCH 1/2] objtool: Fix clang switch table edge case Josh Poimboeuf 2020-02-18 19:57 ` Nathan Chancellor 2020-02-21 9:50 ` [tip: core/objtool] " tip-bot2 for Josh Poimboeuf 2020-02-18 3:41 ` [PATCH 2/2] objtool: Improve call destination function detection Josh Poimboeuf 2020-02-18 18:13 ` Nick Desaulniers 2020-02-18 19:58 ` Nathan Chancellor 2020-02-21 9:50 ` [tip: core/objtool] " tip-bot2 for Josh Poimboeuf 2020-02-20 19:06 ` [PATCH 0/2] objtool: clang-related fixes Nick Desaulniers 2020-02-20 19:27 ` Borislav Petkov
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