forked from Minki/linux
c6bda7c988
x86-64 has a problem: per-cpu variables are actually represented by their absolute offsets within the per-cpu area, but the symbols are not emitted as absolute. Thus kallsyms naively creates them as offsets from _text, meaning their values change if the kernel is relocated (especially noticeable with CONFIG_RANDOMIZE_BASE): $ egrep ' (gdt_|_(stext|_per_cpu_))' /root/kallsyms.nokaslr 0000000000000000 D __per_cpu_start 0000000000004000 D gdt_page 0000000000014280 D __per_cpu_end ffffffff810001c8 T _stext ffffffff81ee53c0 D __per_cpu_offset $ egrep ' (gdt_|_(stext|_per_cpu_))' /root/kallsyms.kaslr1 000000001f200000 D __per_cpu_start 000000001f204000 D gdt_page 000000001f214280 D __per_cpu_end ffffffffa02001c8 T _stext ffffffffa10e53c0 D __per_cpu_offset Making them absolute symbols is the Right Thing, but requires fixes to the relocs tool. So for the moment, we add a --absolute-percpu option which makes them absolute from a kallsyms perspective: $ egrep ' (gdt_|_(stext|_per_cpu_))' /proc/kallsyms # no KASLR 0000000000000000 A __per_cpu_start 000000000000a000 A gdt_page 0000000000013040 A __per_cpu_end ffffffff802001c8 T _stext ffffffff8099b180 D __per_cpu_offset ffffffff809a3000 D __per_cpu_load $ egrep ' (gdt_|_(stext|_per_cpu_))' /proc/kallsyms # With KASLR 0000000000000000 A __per_cpu_start 000000000000a000 A gdt_page 0000000000013040 A __per_cpu_end ffffffff89c001c8 T _stext ffffffff8a39d180 D __per_cpu_offset ffffffff8a3a5000 D __per_cpu_load Based-on-the-original-screenplay-by: Andy Honig <ahonig@google.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Kees Cook <keescook@chromium.org> |
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| .. | ||
| basic | ||
| coccinelle | ||
| dtc | ||
| genksyms | ||
| kconfig | ||
| ksymoops | ||
| mod | ||
| package | ||
| rt-tester | ||
| selinux | ||
| tracing | ||
| .gitignore | ||
| analyze_suspend.py | ||
| asn1_compiler.c | ||
| bin2c.c | ||
| bloat-o-meter | ||
| bootgraph.pl | ||
| checkincludes.pl | ||
| checkkconfigsymbols.sh | ||
| checkpatch.pl | ||
| checkstack.pl | ||
| checksyscalls.sh | ||
| checkversion.pl | ||
| cleanfile | ||
| cleanpatch | ||
| coccicheck | ||
| config | ||
| conmakehash.c | ||
| decodecode | ||
| depmod.sh | ||
| diffconfig | ||
| docproc.c | ||
| export_report.pl | ||
| extract-ikconfig | ||
| extract-vmlinux | ||
| gcc-goto.sh | ||
| gcc-version.sh | ||
| gcc-x86_32-has-stack-protector.sh | ||
| gcc-x86_64-has-stack-protector.sh | ||
| gen_initramfs_list.sh | ||
| get_maintainer.pl | ||
| gfp-translate | ||
| headerdep.pl | ||
| headers_check.pl | ||
| headers_install.sh | ||
| headers.sh | ||
| kallsyms.c | ||
| Kbuild.include | ||
| kernel-doc | ||
| Lindent | ||
| link-vmlinux.sh | ||
| Makefile | ||
| Makefile.asm-generic | ||
| Makefile.build | ||
| Makefile.clean | ||
| Makefile.fwinst | ||
| Makefile.headersinst | ||
| Makefile.help | ||
| Makefile.host | ||
| Makefile.lib | ||
| Makefile.modbuiltin | ||
| Makefile.modinst | ||
| Makefile.modpost | ||
| Makefile.modsign | ||
| makelst | ||
| markup_oops.pl | ||
| mkcompile_h | ||
| mkmakefile | ||
| mksysmap | ||
| mkuboot.sh | ||
| mkversion | ||
| module-common.lds | ||
| namespace.pl | ||
| patch-kernel | ||
| pnmtologo.c | ||
| profile2linkerlist.pl | ||
| recordmcount.c | ||
| recordmcount.h | ||
| recordmcount.pl | ||
| setlocalversion | ||
| show_delta | ||
| sign-file | ||
| sortextable.c | ||
| sortextable.h | ||
| tags.sh | ||
| unifdef.c | ||
| ver_linux | ||
| xz_wrap.sh | ||