2b6e818fc6
[ Upstream commit aabdc960a283ba78086b0bf66ee74326f49e218e ]
Currently, comparisons to 'm' or 'n' result in incorrect output.
[Test Code]
config MODULES
def_bool y
modules
config A
def_tristate m
config B
def_bool A > n
CONFIG_B is unset, while CONFIG_B=y is expected.
The reason for the issue is because Kconfig compares the tristate values
as strings.
Currently, the .type fields in the constant symbol definitions,
symbol_{yes,mod,no} are unspecified, i.e., S_UNKNOWN.
When expr_calc_value() evaluates 'A > n', it checks the types of 'A' and
'n' to determine how to compare them.
The left-hand side, 'A', is a tristate symbol with a value of 'm', which
corresponds to a numeric value of 1. (Internally, 'y', 'm', and 'n' are
represented as 2, 1, and 0, respectively.)
The right-hand side, 'n', has an unknown type, so it is treated as the
string "n" during the comparison.
expr_calc_value() compares two values numerically only when both can
have numeric values. Otherwise, they are compared as strings.
symbol numeric value ASCII code
-------------------------------------
y 2 0x79
m 1 0x6d
n 0 0x6e
'm' is greater than 'n' if compared numerically (since 1 is greater
than 0), but smaller than 'n' if compared as strings (since the ASCII
code 0x6d is smaller than 0x6e).
Specifying .type=S_TRISTATE for symbol_{yes,mod,no} fixes the above
test code.
Doing so, however, would cause a regression to the following test code.
[Test Code 2]
config MODULES
def_bool n
modules
config A
def_tristate n
config B
def_bool A = m
You would get CONFIG_B=y, while CONFIG_B should not be set.
The reason is because sym_get_string_value() turns 'm' into 'n' when the
module feature is disabled. Consequently, expr_calc_value() evaluates
'A = n' instead of 'A = m'. This oddity has been hidden because the type
of 'm' was previously S_UNKNOWN instead of S_TRISTATE.
sym_get_string_value() should not tweak the string because the tristate
value has already been correctly calculated. There is no reason to
return the string "n" where its tristate value is mod.
Fixes: 31847b67bec0 ("kconfig: allow use of relations other than (in)equality")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| .. | ||
| atomic | ||
| basic | ||
| clang-tools | ||
| coccinelle | ||
| dtc | ||
| dummy-tools | ||
| gcc-plugins | ||
| gdb | ||
| genksyms | ||
| kconfig | ||
| ksymoops | ||
| mod | ||
| package | ||
| selinux | ||
| tracing | ||
| .gitignore | ||
| as-version.sh | ||
| asn1_compiler.c | ||
| bloat-o-meter | ||
| bootgraph.pl | ||
| bpf_doc.py | ||
| cc-can-link.sh | ||
| cc-version.sh | ||
| check_extable.sh | ||
| check-git | ||
| check-sysctl-docs | ||
| checkdeclares.pl | ||
| checkincludes.pl | ||
| checkkconfigsymbols.py | ||
| checkpatch.pl | ||
| checkstack.pl | ||
| checksyscalls.sh | ||
| checkversion.pl | ||
| cleanfile | ||
| cleanpatch | ||
| coccicheck | ||
| config | ||
| const_structs.checkpatch | ||
| decode_stacktrace.sh | ||
| decodecode | ||
| depmod.sh | ||
| dev-needs.sh | ||
| diffconfig | ||
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| extract-sys-certs.pl | ||
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| faddr2line | ||
| file-size.sh | ||
| find-unused-docs.sh | ||
| gcc-x86_32-has-stack-protector.sh | ||
| gcc-x86_64-has-stack-protector.sh | ||
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| generate_rust_analyzer.py | ||
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| headers_install.sh | ||
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| install.sh | ||
| jobserver-exec | ||
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| Kbuild.include | ||
| Kconfig.include | ||
| kernel-doc | ||
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| Lindent | ||
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| Makefile | ||
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| Makefile.modfinal | ||
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| Makefile.randstruct | ||
| Makefile.ubsan | ||
| Makefile.userprogs | ||
| Makefile.vdsoinst | ||
| Makefile.vmlinux | ||
| Makefile.vmlinux_o | ||
| makelst | ||
| markup_oops.pl | ||
| min-tool-version.sh | ||
| misc-check | ||
| mkcompile_h | ||
| mksysmap | ||
| mkuboot.sh | ||
| module.lds.S | ||
| modules-check.sh | ||
| nsdeps | ||
| objdiff | ||
| objdump-func | ||
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| parse-maintainers.pl | ||
| patch-kernel | ||
| profile2linkerlist.pl | ||
| prune-kernel | ||
| recordmcount.c | ||
| recordmcount.h | ||
| recordmcount.pl | ||
| relocs_check.sh | ||
| remove-stale-files | ||
| rust_is_available_bindgen_libclang.h | ||
| rust_is_available_test.py | ||
| rust_is_available.sh | ||
| rustdoc_test_builder.rs | ||
| rustdoc_test_gen.rs | ||
| setlocalversion | ||
| show_delta | ||
| sign-file.c | ||
| sorttable.c | ||
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| stackdelta | ||
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