| d39f82a0 | 24-Mar-2025 |
Josh Poimboeuf <[email protected]> |
objtool: Reduce CONFIG_OBJTOOL_WERROR verbosity
Remove the following from CONFIG_OBJTOOL_WERROR:
* backtrace
* "upgraded warnings to errors" message
* cmdline args
This makes the default o
objtool: Reduce CONFIG_OBJTOOL_WERROR verbosity
Remove the following from CONFIG_OBJTOOL_WERROR:
* backtrace
* "upgraded warnings to errors" message
* cmdline args
This makes the default output less cluttered and makes it easier to spot
the actual warnings. Note the above options are still are available
with --verbose or OBJTOOL_VERBOSE=1.
Also, do the cmdline arg printing on all warnings, regardless of werror.
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/d61df69f64b396fa6b2a1335588aad7a34ea9e71.1742852846.git.jpoimboe@kernel.org
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| c5995abe | 24-Mar-2025 |
Josh Poimboeuf <[email protected]> |
objtool: Improve error handling
Fix some error handling issues, improve error messages, properly
distinguish betwee errors and warnings, and generally try to make all
the error handling more consist
objtool: Improve error handling
Fix some error handling issues, improve error messages, properly
distinguish betwee errors and warnings, and generally try to make all
the error handling more consistent.
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/3094bb4463dad29b6bd1bea03848d1571ace771c.1742852846.git.jpoimboe@kernel.org
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| 1154bbd3 | 24-Mar-2025 |
Josh Poimboeuf <[email protected]> |
objtool: Fix X86_FEATURE_SMAP alternative handling
For X86_FEATURE_SMAP alternatives which replace NOP with STAC or CLAC,
uaccess validation skips the NOP branch to avoid following impossible
code p
objtool: Fix X86_FEATURE_SMAP alternative handling
For X86_FEATURE_SMAP alternatives which replace NOP with STAC or CLAC,
uaccess validation skips the NOP branch to avoid following impossible
code paths, e.g. where a STAC would be patched but a CLAC wouldn't.
However, it's not safe to assume an X86_FEATURE_SMAP alternative is
patching STAC/CLAC. There can be other alternatives, like
static_cpu_has(), where both branches need to be validated.
Fix that by repurposing ANNOTATE_IGNORE_ALTERNATIVE for skipping either
original instructions or new ones. This is a more generic approach
which enables the removal of the feature checking hacks and the
insn->ignore bit.
Fixes the following warnings:
arch/x86/mm/fault.o: warning: objtool: do_user_addr_fault+0x8ec: __stack_chk_fail() missing __noreturn in .c/.h or NORETURN() in noreturns.h
arch/x86/mm/fault.o: warning: objtool: do_user_addr_fault+0x8f1: unreachable instruction
[ mingo: Fix up conflicts with recent x86 changes. ]
Fixes: ea24213d8088 ("objtool: Add UACCESS validation")
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/de0621ca242130156a55d5d74fed86994dfa4c9c.1742852846.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
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| aa8b3e64 | 14-Mar-2025 |
Josh Poimboeuf <[email protected]> |
objtool: Create backup on error and print args
Recreating objtool errors can be a manual process. Kbuild removes the
object, so it has to be compiled or linked again before running objtool.
Then th
objtool: Create backup on error and print args
Recreating objtool errors can be a manual process. Kbuild removes the
object, so it has to be compiled or linked again before running objtool.
Then the objtool args need to be reversed engineered.
Make that all easier by automatically making a backup of the object file
on error, and print a modified version of the args which can be used to
recreate.
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/7571e30636359b3e173ce6e122419452bb31882f.1741975349.git.jpoimboe@kernel.org
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| bb622439 | 14-Mar-2025 |
Josh Poimboeuf <[email protected]> |
objtool: Add --Werror option
Any objtool warning has the potential of reflecting (or triggering) a
major bug in the kernel or compiler which could result in crashing the
kernel or breaking the livep
objtool: Add --Werror option
Any objtool warning has the potential of reflecting (or triggering) a
major bug in the kernel or compiler which could result in crashing the
kernel or breaking the livepatch consistency model.
In preparation for failing the build on objtool errors/warnings, add a
new --Werror option.
[ jpoimboe: commit log, comments, error out on fatal errors too ]
Co-developed-by: Brendan Jackman <[email protected]>
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/e423ea4ec297f510a108aa6c78b52b9fe30fa8c1.1741975349.git.jpoimboe@kernel.org
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| 5a406031 | 14-Mar-2025 |
Josh Poimboeuf <[email protected]> |
objtool: Add --output option
Add option to allow writing the changed binary to a separate file rather
than changing it in place.
Libelf makes this suprisingly hard, so take the easy way out and jus
objtool: Add --output option
Add option to allow writing the changed binary to a separate file rather
than changing it in place.
Libelf makes this suprisingly hard, so take the easy way out and just
copy the file before editing it.
Also steal the -o short option from --orc. Nobody will notice ;-)
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/0da308d42d82b3bbed16a31a72d6bde52afcd6bd.1741975349.git.jpoimboe@kernel.org
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| 0a7fb6f0 | 14-Mar-2025 |
Josh Poimboeuf <[email protected]> |
objtool: Increase per-function WARN_FUNC() rate limit
Increase the per-function WARN_FUNC() rate limit from 1 to 2. If the
number of warnings for a given function goes beyond 2, print "skipping
dup
objtool: Increase per-function WARN_FUNC() rate limit
Increase the per-function WARN_FUNC() rate limit from 1 to 2. If the
number of warnings for a given function goes beyond 2, print "skipping
duplicate warning(s)". This helps root out additional warnings in a
function that might be hiding behind the first one.
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/aec318d66c037a51c9f376d6fb0e8ff32812a037.1741975349.git.jpoimboe@kernel.org
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| c4b93b06 | 11-Feb-2025 |
Tiezhu Yang <[email protected]> |
objtool: Handle PC relative relocation type
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 typ
objtool: Handle PC relative relocation type
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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Acked-by: Huacai Chen <[email protected]>
Signed-off-by: Josh Poimboeuf <[email protected]>
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| d5ab2bc3 | 11-Mar-2024 |
Tiezhu Yang <[email protected]> |
objtool: Check local label in add_dead_ends()
When update the latest upstream gcc and binutils, it generates more
objtool warnings on LoongArch, like this:
init/main.o: warning: objtool: unexpect
objtool: Check local label in add_dead_ends()
When update the latest upstream gcc and binutils, it generates more
objtool warnings on LoongArch, like this:
init/main.o: warning: objtool: unexpected relocation symbol type in .rela.discard.unreachable
We can see that the reloc sym name is local label instead of section in
relocation section '.rela.discard.unreachable', in this case, the reloc
sym type is STT_NOTYPE instead of STT_SECTION.
As suggested by Peter Zijlstra, we add a "local_label" member in struct
symbol, then set it as true if symbol type is STT_NOTYPE and symbol name
starts with ".L" string in classify_symbols().
Let's check reloc->sym->local_label to not return -1 in add_dead_ends(),
and also use reloc->sym->offset instead of reloc addend which is 0 to
find the corresponding instruction. At the same time, let's replace the
variable "addend" with "offset" to reflect the reality.
Here are some detailed info:
[fedora@linux 6.8.test]$ gcc --version
gcc (GCC) 14.0.1 20240129 (experimental)
[fedora@linux 6.8.test]$ as --version
GNU assembler (GNU Binutils) 2.42.50.20240129
[fedora@linux 6.8.test]$ readelf -r init/main.o | grep -A 2 "rela.discard.unreachable"
Relocation section '.rela.discard.unreachable' at offset 0x6028 contains 1 entry:
Offset Info Type Sym. Value Sym. Name + Addend
000000000000 00d900000063 R_LARCH_32_PCREL 00000000000002c4 .L500^B1 + 0
Signed-off-by: Tiezhu Yang <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>
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| 02b54001 | 30-May-2023 |
Josh Poimboeuf <[email protected]> |
objtool: Shrink elf hash nodes
Instead of using hlist for the 'struct elf' hashes, use a custom
single-linked list scheme.
With allyesconfig + CONFIG_DEBUG_INFO:
- Before: peak heap memory consump
objtool: Shrink elf hash nodes
Instead of using hlist for the 'struct elf' hashes, use a custom
single-linked list scheme.
With allyesconfig + CONFIG_DEBUG_INFO:
- Before: peak heap memory consumption: 36.89G
- After: peak heap memory consumption: 35.12G
Link: https://lore.kernel.org/r/6e8cd305ed22e743c30d6e72cfdc1be20fb94cd4.1685464332.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <[email protected]>
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| 890f10a4 | 30-May-2023 |
Josh Poimboeuf <[email protected]> |
objtool: Shrink reloc->sym_reloc_entry
Convert it to a singly-linked list.
With allyesconfig + CONFIG_DEBUG_INFO:
- Before: peak heap memory consumption: 38.64G
- After: peak heap memory consumpt
objtool: Shrink reloc->sym_reloc_entry
Convert it to a singly-linked list.
With allyesconfig + CONFIG_DEBUG_INFO:
- Before: peak heap memory consumption: 38.64G
- After: peak heap memory consumption: 36.89G
Link: https://lore.kernel.org/r/a51f0a6f9bbf2494d5a3a449807307e78a940988.1685464332.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <[email protected]>
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