Messages in this thread |  | | Date | Fri, 11 Apr 2025 09:47:51 +0200 | | From | "Arnd Bergmann" <> | | Subject | Re: [PATCH] scripts/mksysmap: skip objtool __pfx_ symbols |
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On Fri, Apr 11, 2025, at 08:50, Peter Zijlstra wrote: > On Tue, Apr 08, 2025 at 06:58:49PM -0700, Josh Poimboeuf wrote: >> On Fri, Mar 28, 2025 at 11:48:19AM +0100, Arnd Bergmann wrote: >> >> For example, FineIBT writes code in the __pfx area which can trigger an >> #UD. And we'd want a sane backtrace for that. > > On top of that, clang kcfi builds do a similar thing, they will generate > __cfi_ prefixed symbols. > > And yes, those symbols exist for a reason, there is code there under > various circumstances and backtraces look really weird without these > symbols on -- notably the code in the prefix will be attributed to > whatever symbol comes before, most confusing. > > So yeah, don't remove these symbols, and fix the kunit test.
kallsyms already removes some CFI symbol names based on regular expressions:
# CFI type identifiers / __kcfi_typeid_/d / __kvm_nvhe___kcfi_typeid_/d / __pi___kcfi_typeid_/d
Do you think it should not remove some of them?
I ran into another problem with generated symbols that I don't understand yet, and added this line to avoid the build failures:
/ _GLOBAL__sub_/d
This one is 534 characters long: _GLOBAL__sub_I_65535_1_snnnng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nnng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nnnng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nnng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nnnnng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nnng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nnnng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nnng1h2i3j4k5l6m7ng1h2i3j4k5l6m7nng1h2i3j4k5l6m7ng1h2i3j4k5l6m7n
Arnd
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