• Zhen Lei's avatar
    kallsyms: Correctly sequence symbols when CONFIG_LTO_CLANG=y · 010a0aad
    Zhen Lei authored
    LLVM appends various suffixes for local functions and variables, suffixes
    observed:
     - foo.llvm.[0-9a-f]+
     - foo.[0-9a-f]+
    
    Therefore, when CONFIG_LTO_CLANG=y, kallsyms_lookup_name() needs to
    truncate the suffix of the symbol name before comparing the local function
    or variable name.
    
    Old implementation code:
    -	if (strcmp(namebuf, name) == 0)
    -		return kallsyms_sym_address(i);
    -	if (cleanup_symbol_name(namebuf) && strcmp(namebuf, name) == 0)
    -		return kallsyms_sym_address(i);
    
    The preceding process is traversed by address from low to high. That is,
    for those with the same name after the suffix is removed, the one with
    the smallest address is returned first. Therefore, when sorting in the
    tool, if the raw names are the same, they should be sorted by address in
    ascending order.
    
    ASCII[.]   = 2e
    ASCII[0-9] = 30,39
    ASCII[A-Z] = 41,5a
    ASCII[_]   = 5f
    ASCII[a-z] = 61,7a
    
    According to the preceding ASCII code values, the following sorting result
    is strictly followed.
     ---------------------------------
    |    main-key     |    sub-key    |
    |---------------------------------|
    |                 |  addr_lowest  |
    | <name>          |      ...      |
    | <name>.<suffix> |      ...      |
    |                 |  addr_highest |
    |---------------------------------|
    | <name>?<others> |               |   //? is [_A-Za-z0-9]
     ---------------------------------
    Signed-off-by: default avatarZhen Lei <thunder.leizhen@huawei.com>
    Signed-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
    010a0aad
link-vmlinux.sh 7.51 KB