kernel/linux.git/scripts/kallsyms.c, branch v7.0-rc7

kallsyms: Get rid of kallsyms relative base

2026-01-22T22:58:22+00:00

When the kallsyms relative base was introduced, per-CPU variable references on x86_64 SMP were implemented as offsets into the respective per-CPU region, rather than offsets relative to the location of the variable's template in the kernel image, which is how other architectures implement it. This required kallsyms to reason about the difference between the two, and the sign of the value in the kallsyms_offsets[] array was used to distinguish them. This meant that negative offsets were not permitted for ordinary variables, and so it was crucial that the relative base was chosen such that all offsets were positive numbers. This is no longer needed: instead, the offsets can simply be encoded as values in the range -/+ 2 GiB, which is precisely what PC32 relocations provide on most architectures. So it is possible to simplify the logic, and just use _text as the anchor directly, and let the linker calculate the final value based on the location of the entry itself. Some architectures (nios2, extensa) do not support place-relative relocations at all, but these are all 32-bit and non-relocatable, and so there is no need for place-relative relocations in the first place, and the actual symbol values can just be stored directly. This makes all entries in the kallsyms_offsets[] array visible as place-relative references in the ELF metadata, which will be important when implementing ELF-based fg-kaslr. Reviewed-by: Kees Cook Signed-off-by: Ard Biesheuvel Link: https://patch.msgid.link/20260116093359.2442297-6-ardb+git@google.com Signed-off-by: Nathan Chancellor

kallsyms: Remove KALLSYMS_ABSOLUTE_PERCPU

2025-02-18T09:16:04+00:00

x86-64 was the only user. Signed-off-by: Brian Gerst Signed-off-by: Ingo Molnar Reviewed-by: Ard Biesheuvel Cc: Linus Torvalds Link: https://lore.kernel.org/r/20250123190747.745588-16-brgerst@gmail.com

kallsyms: change overflow variable to bool type

2024-09-20T00:21:52+00:00

Change the 'overflow' variable to bool. Also, remove unnecessary parentheses. Signed-off-by: Masahiro Yamada

kallsyms: squash output_address()

2024-09-20T00:21:52+00:00

After commit 64e166099b69 ("kallsyms: get rid of code for absolute, kallsyms"), there is only one call site for output_address(). Squash it. Signed-off-by: Masahiro Yamada

kallsyms: use xmalloc() and xrealloc()

2024-09-01T11:34:48+00:00

When malloc() or realloc() fails, there is not much userspace programs can do. xmalloc() and xrealloc() are useful to bail out on a memory allocation failure. Signed-off-by: Masahiro Yamada

kallsyms: Do not cleanup .llvm. suffix before sorting symbols

2024-08-15T16:33:34+00:00

Cleaning up the symbols causes various issues afterwards. Let's sort the list based on original name. Signed-off-by: Song Liu Fixes: 8cc32a9bbf29 ("kallsyms: strip LTO-only suffixes from promoted global functions") Reviewed-by: Masami Hiramatsu (Google) Tested-by: Masami Hiramatsu (Google) Acked-by: Petr Mladek Reviewed-by: Sami Tolvanen Reviewed-by: Luis Chamberlain Link: https://lore.kernel.org/r/20240807220513.3100483-2-song@kernel.org Signed-off-by: Kees Cook

kallsyms: change sym_entry::percpu_absolute to bool type

2024-07-21T16:24:22+00:00

This field is boolean. Signed-off-by: Masahiro Yamada

kallsyms: unify seq and start_pos fields of struct sym_entry

2024-07-21T16:24:22+00:00

The struct sym_entry uses the 'seq' and 'start_pos' fields to remember the index in the symbol table. They serve the same purpose and are not used simultaneously. Unify them. Signed-off-by: Masahiro Yamada

kallsyms: add more original symbol type/name in comment lines

2024-07-21T16:24:22+00:00

Commit bea5b7450474 ("kallsyms: expand symbol name into comment for debugging") added the uncompressed type/name in the comment lines of kallsyms_offsets. It would be useful to do the same for kallsyms_names and kallsyms_seqs_of_names. Signed-off-by: Masahiro Yamada

kallsyms: use \t instead of a tab in printf()

2024-07-21T16:24:22+00:00

This string literal uses a mixture of \t escape sequences and a tab. Use \t consistently. Signed-off-by: Masahiro Yamada