Re: [PATCH/RFC] powerpc/module_64: allow .init_array constructors to run
From: Christophe Leroy <hidden>
Date: 2022-07-07 11:03:18
Also in:
lkml
Le 17/08/2021 à 15:02, Jan Stancek a écrit :
gcov and kasan rely on compiler generated constructor code. For modules, gcc-8 with gcov enabled generates .init_array section, but on ppc64le it doesn't get executed. find_module_sections() never finds .init_array section, because module_frob_arch_sections() renames it to _init_array. Avoid renaming .init_array section, so do_mod_ctors() can use it. Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <redacted> Cc: Christophe Leroy <redacted> Signed-off-by: Jan Stancek <jstancek@redhat.com>
Does commit d4be60fe66b7 ("powerpc/module_64: use module_init_section
instead of patching names") fixes your issue ?
If not, please rebase and resubmit.
Thanks
Christophe
quoted hunk ↗ jump to hunk
--- I wasn't able to trace the comment: "We don't handle .init for the moment: rename to _init" to original patch (it pre-dates .git). I'm not sure if it still applies today, so I limited patch to .init_array. This fixes gcov for modules for me on ppc64le 5.14.0-rc6. Renaming issue is also mentioned in kasan patches here: https://patchwork.ozlabs.org/project/linuxppc-dev/cover/20210319144058.772525-1-dja@axtens arch/powerpc/kernel/module_64.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index 6baa676e7cb6..c604b13ea6bf 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c@@ -299,8 +299,16 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr, sechdrs[i].sh_size); /* We don't handle .init for the moment: rename to _init */ - while ((p = strstr(secstrings + sechdrs[i].sh_name, ".init"))) + while ((p = strstr(secstrings + sechdrs[i].sh_name, ".init"))) { +#ifdef CONFIG_CONSTRUCTORS + /* find_module_sections() needs .init_array intact */ + if (strstr(secstrings + sechdrs[i].sh_name, + ".init_array")) { + break; + } +#endif p[0] = '_'; + } if (sechdrs[i].sh_type == SHT_SYMTAB) dedotify((void *)hdr + sechdrs[i].sh_offset,