The string functions can currently not be used safely in early boot code, at least on x86, as some of that code will be executing out of the identity mapping rather than kernel virtual address space. Instrumentation options that insert accesses to any global data will cause a crash.
I'm proposing to disable instrumentation for lib/string.c to allow the string functions to be usable, and the second patch is an example use case. However, I'm not very familiar with the actual uses of that instrumentation and don't know whether disabling it all for lib/string would be a terrible idea, hence the RFC. Thanks. Arvind Sankar (2): lib/string: Disable instrumentation x86/cmdline: Use strscpy to initialize boot_command_line arch/x86/kernel/head64.c | 2 +- arch/x86/kernel/head_32.S | 11 +++++------ lib/Makefile | 11 +++++++---- 3 files changed, 13 insertions(+), 11 deletions(-) -- 2.26.2