linux-stable.git/tools/objtool, branch v6.14.2 Linux kernel stable tree objtool: Fix verbose disassembly if CROSS_COMPILE isn't set 2025-04-10T12:44:36+00:00 David Laight david.laight.linux@gmail.com 2025-04-01T04:26:42+00:00 ffb8e7f715c4761774730b6efba2c113ec8b5da0 [ Upstream commit e77956e4e5c11218e60a1fe8cdbccd02476f2e56 ] In verbose mode, when printing the disassembly of affected functions, if CROSS_COMPILE isn't set, the objdump command string gets prefixed with "(null)". Somehow this worked before. Maybe some versions of glibc return an empty string instead of NULL. Fix it regardless. [ jpoimboe: Rewrite commit log. ] Fixes: ca653464dd097 ("objtool: Add verbose option for disassembling affected functions") Signed-off-by: David Laight <david.laight.linux@gmail.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250215142321.14081-1-david.laight.linux@gmail.com Link: https://lore.kernel.org/r/b931a4786bc0127aa4c94e8b35ed617dcbd3d3da.1743481539.git.jpoimboe@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e77956e4e5c11218e60a1fe8cdbccd02476f2e56 ]

In verbose mode, when printing the disassembly of affected functions, if
CROSS_COMPILE isn't set, the objdump command string gets prefixed with
"(null)".

Somehow this worked before.  Maybe some versions of glibc return an
empty string instead of NULL.  Fix it regardless.

[ jpoimboe: Rewrite commit log. ]

Fixes: ca653464dd097 ("objtool: Add verbose option for disassembling affected functions")
Signed-off-by: David Laight <david.laight.linux@gmail.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250215142321.14081-1-david.laight.linux@gmail.com
Link: https://lore.kernel.org/r/b931a4786bc0127aa4c94e8b35ed617dcbd3d3da.1743481539.git.jpoimboe@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
objtool: Fix segfault in ignore_unreachable_insn() 2025-04-10T12:44:36+00:00 Josh Poimboeuf jpoimboe@kernel.org 2025-03-28T05:04:21+00:00 556b6ccf0b9dbac2d5b4676cdcb4ba8567b44b0b [ Upstream commit 69d41d6dafff0967565b971d950bd10443e4076c ] Check 'prev_insn' before dereferencing it. Fixes: bd841d6154f5 ("objtool: Fix CONFIG_UBSAN_TRAP unreachable warnings") Reported-by: Arnd Bergmann <arnd@arndb.de> Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/5df4ff89c9e4b9e788b77b0531234ffa7ba03e9e.1743136205.git.jpoimboe@kernel.org Closes: https://lore.kernel.org/d86b4cc6-0b97-4095-8793-a7384410b8ab@app.fastmail.com Closes: https://lore.kernel.org/Z-V_rruKY0-36pqA@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 69d41d6dafff0967565b971d950bd10443e4076c ]

Check 'prev_insn' before dereferencing it.

Fixes: bd841d6154f5 ("objtool: Fix CONFIG_UBSAN_TRAP unreachable warnings")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/5df4ff89c9e4b9e788b77b0531234ffa7ba03e9e.1743136205.git.jpoimboe@kernel.org

Closes: https://lore.kernel.org/d86b4cc6-0b97-4095-8793-a7384410b8ab@app.fastmail.com
Closes: https://lore.kernel.org/Z-V_rruKY0-36pqA@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
objtool: Fix detection of consecutive jump tables on Clang 20 2025-04-10T12:44:35+00:00 Josh Poimboeuf jpoimboe@kernel.org 2025-03-24T21:55:51+00:00 88e923d140fa77cad6d5d6ea44d6fa6b55c59d7b [ Upstream commit ef753d66051ca03bee1982ce047f9eaf90f81ab4 ] The jump table detection code assumes jump tables are in the same order as their corresponding indirect branches. That's apparently not always true with Clang 20. Fix that by changing how multiple jump tables are detected. In the first detection pass, mark the beginning of each jump table so the second pass can tell where one ends and the next one begins. Fixes the following warnings: vmlinux.o: warning: objtool: SiS_GetCRT2Ptr+0x1ad: stack state mismatch: cfa1=4+8 cfa2=5+16 sound/core/seq/snd-seq.o: warning: objtool: cc_ev_to_ump_midi2+0x589: return with modified stack frame Fixes: be2f0b1e1264 ("objtool: Get rid of reloc->jump_table_start") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/141752fff614eab962dba6bdfaa54aa67ff03bba.1742852846.git.jpoimboe@kernel.org Closes: https://lore.kernel.org/oe-kbuild-all/202503171547.LlCTJLQL-lkp@intel.com/ Closes: https://lore.kernel.org/oe-kbuild-all/202503200535.J3hAvcjw-lkp@intel.com/ Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ef753d66051ca03bee1982ce047f9eaf90f81ab4 ]

The jump table detection code assumes jump tables are in the same order
as their corresponding indirect branches.  That's apparently not always
true with Clang 20.

Fix that by changing how multiple jump tables are detected.  In the
first detection pass, mark the beginning of each jump table so the
second pass can tell where one ends and the next one begins.

Fixes the following warnings:

  vmlinux.o: warning: objtool: SiS_GetCRT2Ptr+0x1ad: stack state mismatch: cfa1=4+8 cfa2=5+16
  sound/core/seq/snd-seq.o: warning: objtool: cc_ev_to_ump_midi2+0x589: return with modified stack frame

Fixes: be2f0b1e1264 ("objtool: Get rid of reloc->jump_table_start")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/141752fff614eab962dba6bdfaa54aa67ff03bba.1742852846.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/oe-kbuild-all/202503171547.LlCTJLQL-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202503200535.J3hAvcjw-lkp@intel.com/
Signed-off-by: Sasha Levin <sashal@kernel.org>
objtool: Handle PC relative relocation type 2025-04-10T12:44:35+00:00 Tiezhu Yang yangtiezhu@loongson.cn 2025-02-11T11:50:12+00:00 a7a8e0ccaf730b25b36d63bd4260307e99c5cda8 [ Upstream commit c4b93b06230ae49870187189d9f7342f6ad4f14e ] For the most part, an absolute relocation type is used for rodata. In the case of STT_SECTION, reloc->sym->offset is always zero, for the other symbol types, reloc_addend(reloc) is always zero, thus it can use a simple statement "reloc->sym->offset + reloc_addend(reloc)" to obtain the symbol offset for various symbol types. When compiling on LoongArch, there exist PC relative relocation types for rodata, it needs to calculate the symbol offset with "S + A - PC" according to the spec of "ELF for the LoongArch Architecture". If there is only one jump table in the rodata, the "PC" is the entry address which is equal with the value of reloc_offset(reloc), at this time, reloc_offset(table) is 0. If there are many jump tables in the rodata, the "PC" is the offset of the jump table's base address which is equal with the value of reloc_offset(reloc) - reloc_offset(table). So for LoongArch, if the relocation type is PC relative, it can use a statement "reloc_offset(reloc) - reloc_offset(table)" to get the "PC" value when calculating the symbol offset with "S + A - PC" for one or many jump tables in the rodata. Add an arch-specific function arch_jump_table_sym_offset() to assign the symbol offset, for the most part that is an absolute relocation, the default value is "reloc->sym->offset + reloc_addend(reloc)" in the weak definition, it can be overridden by each architecture that has different requirements. Link: https://github.com/loongson/la-abi-specs/blob/release/laelf.adoc Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Link: https://lore.kernel.org/r/20250211115016.26913-4-yangtiezhu@loongson.cn Acked-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Stable-dep-of: ef753d66051c ("objtool: Fix detection of consecutive jump tables on Clang 20") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c4b93b06230ae49870187189d9f7342f6ad4f14e ]

For the most part, an absolute relocation type is used for rodata.
In the case of STT_SECTION, reloc->sym->offset is always zero, for
the other symbol types, reloc_addend(reloc) is always zero, thus it
can use a simple statement "reloc->sym->offset + reloc_addend(reloc)"
to obtain the symbol offset for various symbol types.

When compiling on LoongArch, there exist PC relative relocation types
for rodata, it needs to calculate the symbol offset with "S + A - PC"
according to the spec of "ELF for the LoongArch Architecture".

If there is only one jump table in the rodata, the "PC" is the entry
address which is equal with the value of reloc_offset(reloc), at this
time, reloc_offset(table) is 0.

If there are many jump tables in the rodata, the "PC" is the offset
of the jump table's base address which is equal with the value of
reloc_offset(reloc) - reloc_offset(table).

So for LoongArch, if the relocation type is PC relative, it can use a
statement "reloc_offset(reloc) - reloc_offset(table)" to get the "PC"
value when calculating the symbol offset with "S + A - PC" for one or
many jump tables in the rodata.

Add an arch-specific function arch_jump_table_sym_offset() to assign
the symbol offset, for the most part that is an absolute relocation,
the default value is "reloc->sym->offset + reloc_addend(reloc)" in
the weak definition, it can be overridden by each architecture that
has different requirements.

Link: https://github.com/loongson/la-abi-specs/blob/release/laelf.adoc
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Link: https://lore.kernel.org/r/20250211115016.26913-4-yangtiezhu@loongson.cn
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Stable-dep-of: ef753d66051c ("objtool: Fix detection of consecutive jump tables on Clang 20")
Signed-off-by: Sasha Levin <sashal@kernel.org>
objtool: Handle different entry size of rodata 2025-04-10T12:44:35+00:00 Tiezhu Yang yangtiezhu@loongson.cn 2025-02-11T11:50:11+00:00 4f47818652684c185210a4c625e757f9e08d2e95 [ Upstream commit 091bf313f8a852a7f30c3a8dcef569edfd06f5dc ] In the most cases, the entry size of rodata is 8 bytes because the relocation type is 64 bit. There are also 32 bit relocation types, the entry size of rodata should be 4 bytes in this case. Add an arch-specific function arch_reloc_size() to assign the entry size of rodata for x86, powerpc and LoongArch. Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Link: https://lore.kernel.org/r/20250211115016.26913-3-yangtiezhu@loongson.cn Acked-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Stable-dep-of: ef753d66051c ("objtool: Fix detection of consecutive jump tables on Clang 20") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 091bf313f8a852a7f30c3a8dcef569edfd06f5dc ]

In the most cases, the entry size of rodata is 8 bytes because the
relocation type is 64 bit. There are also 32 bit relocation types,
the entry size of rodata should be 4 bytes in this case.

Add an arch-specific function arch_reloc_size() to assign the entry
size of rodata for x86, powerpc and LoongArch.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Link: https://lore.kernel.org/r/20250211115016.26913-3-yangtiezhu@loongson.cn
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Stable-dep-of: ef753d66051c ("objtool: Fix detection of consecutive jump tables on Clang 20")
Signed-off-by: Sasha Levin <sashal@kernel.org>
objtool: Handle various symbol types of rodata 2025-04-10T12:44:34+00:00 Tiezhu Yang yangtiezhu@loongson.cn 2025-02-11T11:50:10+00:00 5c747362c357cd2c91331a0aee28576c8589c688 [ Upstream commit ab6ce22b789622ca732e91cbb3a5cb5ba370cbd0 ] In the relocation section ".rela.rodata" of each .o file compiled with LoongArch toolchain, there are various symbol types such as STT_NOTYPE, STT_OBJECT, STT_FUNC in addition to the usual STT_SECTION, it needs to use reloc symbol offset instead of reloc addend to find the destination instruction in find_jump_table() and add_jump_table(). For the most part, an absolute relocation type is used for rodata. In the case of STT_SECTION, reloc->sym->offset is always zero, and for the other symbol types, reloc_addend(reloc) is always zero, thus it can use a simple statement "reloc->sym->offset + reloc_addend(reloc)" to obtain the symbol offset for various symbol types. Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Link: https://lore.kernel.org/r/20250211115016.26913-2-yangtiezhu@loongson.cn Acked-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Stable-dep-of: ef753d66051c ("objtool: Fix detection of consecutive jump tables on Clang 20") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ab6ce22b789622ca732e91cbb3a5cb5ba370cbd0 ]

In the relocation section ".rela.rodata" of each .o file compiled with
LoongArch toolchain, there are various symbol types such as STT_NOTYPE,
STT_OBJECT, STT_FUNC in addition to the usual STT_SECTION, it needs to
use reloc symbol offset instead of reloc addend to find the destination
instruction in find_jump_table() and add_jump_table().

For the most part, an absolute relocation type is used for rodata. In the
case of STT_SECTION, reloc->sym->offset is always zero, and for the other
symbol types, reloc_addend(reloc) is always zero, thus it can use a simple
statement "reloc->sym->offset + reloc_addend(reloc)" to obtain the symbol
offset for various symbol types.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Link: https://lore.kernel.org/r/20250211115016.26913-2-yangtiezhu@loongson.cn
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Stable-dep-of: ef753d66051c ("objtool: Fix detection of consecutive jump tables on Clang 20")
Signed-off-by: Sasha Levin <sashal@kernel.org>
x86/traps: Make exc_double_fault() consistently noreturn 2025-04-10T12:43:59+00:00 Josh Poimboeuf jpoimboe@kernel.org 2025-03-14T19:28:59+00:00 022d5c7826fa4fe09b6e7080e9253b3a33c3a0cb [ Upstream commit 8085fcd78c1a3dbdf2278732579009d41ce0bc4e ] The CONFIG_X86_ESPFIX64 version of exc_double_fault() can return to its caller, but the !CONFIG_X86_ESPFIX64 version never does. In the latter case the compiler and/or objtool may consider it to be implicitly noreturn. However, due to the currently inflexible way objtool detects noreturns, a function's noreturn status needs to be consistent across configs. The current workaround for this issue is to suppress unreachable warnings for exc_double_fault()'s callers. Unfortunately that can result in ORC coverage gaps and potentially worse issues like inert static calls and silently disabled CPU mitigations. Instead, prevent exc_double_fault() from ever being implicitly marked noreturn by forcing a return behind a never-taken conditional. Until a more integrated noreturn detection method exists, this is likely the least objectionable workaround. Fixes: 55eeab2a8a11 ("objtool: Ignore exc_double_fault() __noreturn warnings") Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Brendan Jackman <jackmanb@google.com> Link: https://lore.kernel.org/r/d1f4026f8dc35d0de6cc61f2684e0cb6484009d1.1741975349.git.jpoimboe@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 8085fcd78c1a3dbdf2278732579009d41ce0bc4e ]

The CONFIG_X86_ESPFIX64 version of exc_double_fault() can return to its
caller, but the !CONFIG_X86_ESPFIX64 version never does.  In the latter
case the compiler and/or objtool may consider it to be implicitly
noreturn.

However, due to the currently inflexible way objtool detects noreturns,
a function's noreturn status needs to be consistent across configs.

The current workaround for this issue is to suppress unreachable
warnings for exc_double_fault()'s callers.  Unfortunately that can
result in ORC coverage gaps and potentially worse issues like inert
static calls and silently disabled CPU mitigations.

Instead, prevent exc_double_fault() from ever being implicitly marked
noreturn by forcing a return behind a never-taken conditional.

Until a more integrated noreturn detection method exists, this is likely
the least objectionable workaround.

Fixes: 55eeab2a8a11 ("objtool: Ignore exc_double_fault() __noreturn warnings")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Brendan Jackman <jackmanb@google.com>
Link: https://lore.kernel.org/r/d1f4026f8dc35d0de6cc61f2684e0cb6484009d1.1741975349.git.jpoimboe@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Merge tag 'objtool-urgent-2025-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2025-03-01T00:45:36+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-03-01T00:45:36+00:00 ad69e021288d04f297c097985513306cbd304be3 Pull objtool fixes from Ingo Molnar: "Fix an objtool false positive, and objtool related build warnings that happens on PIE-enabled architectures such as LoongArch" * tag 'objtool-urgent-2025-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Add bch2_trans_unlocked_or_in_restart_error() to bcachefs noreturns objtool: Fix C jump table annotations for Clang vmlinux.lds: Ensure that const vars with relocations are mapped R/O 
Pull objtool fixes from Ingo Molnar:
 "Fix an objtool false positive, and objtool related build warnings that
  happens on PIE-enabled architectures such as LoongArch"

* tag 'objtool-urgent-2025-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Add bch2_trans_unlocked_or_in_restart_error() to bcachefs noreturns
  objtool: Fix C jump table annotations for Clang
  vmlinux.lds: Ensure that const vars with relocations are mapped R/O
Merge tag 'perf-tools-fixes-for-v6.14-2-2025-02-25' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools 2025-02-25T21:32:32+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-02-25T21:32:32+00:00 9f5270d758d955506dcb114cb863a86b30a4c783 Pull perf tools fixes from Arnaldo Carvalho de Melo: - Fix tools/ quiet build Makefile infrastructure that was broken when working on tools/perf/ without testing on other tools/ living utilities. * tag 'perf-tools-fixes-for-v6.14-2-2025-02-25' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: tools: Remove redundant quiet setup tools: Unify top-level quiet infrastructure 
Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Fix tools/ quiet build Makefile infrastructure that was broken when
   working on tools/perf/ without testing on other tools/ living
   utilities.

* tag 'perf-tools-fixes-for-v6.14-2-2025-02-25' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
  tools: Remove redundant quiet setup
  tools: Unify top-level quiet infrastructure
objtool: Add bch2_trans_unlocked_or_in_restart_error() to bcachefs noreturns 2025-02-25T18:16:31+00:00 Youling Tang tangyouling@kylinos.cn 2025-02-18T06:42:30+00:00 b4ae43b053537ec28f430c0ddb9b916ab296dbe5 Fix the following objtool warning during build time: fs/bcachefs/btree_cache.o: warning: objtool: btree_node_lock.constprop.0() falls through to next function bch2_recalc_btree_reserve() fs/bcachefs/btree_update.o: warning: objtool: bch2_trans_update_get_key_cache() falls through to next function need_whiteout_for_snapshot() bch2_trans_unlocked_or_in_restart_error() is an Obviously Correct (tm) panic() wrapper, add it to the list of known noreturns. Fixes: b318882022a8 ("bcachefs: bch2_trans_verify_not_unlocked_or_in_restart()") Reported-by: k2ci <kernel-bot@kylinos.cn> Signed-off-by: Youling Tang <tangyouling@kylinos.cn> Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev> Link: https://lore.kernel.org/r/20250218064230.219997-1-youling.tang@linux.dev Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> 
Fix the following objtool warning during build time:

  fs/bcachefs/btree_cache.o: warning: objtool: btree_node_lock.constprop.0() falls through to next function bch2_recalc_btree_reserve()
  fs/bcachefs/btree_update.o: warning: objtool: bch2_trans_update_get_key_cache() falls through to next function need_whiteout_for_snapshot()

bch2_trans_unlocked_or_in_restart_error() is an Obviously Correct (tm)
panic() wrapper, add it to the list of known noreturns.

Fixes: b318882022a8 ("bcachefs: bch2_trans_verify_not_unlocked_or_in_restart()")
Reported-by: k2ci <kernel-bot@kylinos.cn>
Signed-off-by: Youling Tang <tangyouling@kylinos.cn>
Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>
Link: https://lore.kernel.org/r/20250218064230.219997-1-youling.tang@linux.dev
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>