Messages in this thread Patch in this message | | | Date | Fri, 23 Aug 2013 18:40:46 +0200 | From | Jan Kiszka <> | Subject | x86-32: Early microcode loading stumbles over disabled DYNAMIC_FTRACE |
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Hi all,
32-bit kernels currently crash/reboot in early microcode loading when non-dynamic function tracing is enabled. Several functions in that path get instrumented with mcount, but its non-dynamic implementation does not work before paging is enabled (it accesses global variables at wrong addresses).
Below some hunks to get it working again - at least in the absence of any microcode in the initrd. Marking all involved functions as __init is another option (as __init implies notrace). But I bet there is more hidden. I see e.g. a pr_warn() in find_cpio_init that should trigger the issue as well if we hit the error it reports (btw. printing at this point of the boot should not work anyway, should it?).
Better ideas?
Jan
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 88d99ea..c093a9c 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -14,6 +14,9 @@ CFLAGS_REMOVE_pvclock.o = -pg CFLAGS_REMOVE_kvmclock.o = -pg CFLAGS_REMOVE_ftrace.o = -pg CFLAGS_REMOVE_early_printk.o = -pg +CFLAGS_REMOVE_microcode_core_early.o = -pg +CFLAGS_REMOVE_microcode_intel_early.o = -pg +CFLAGS_REMOVE_microcode_amd_early.o = -pg endif
CFLAGS_irq.o := -I$(src)/../include/asm/trace diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 96b2c66..0917142 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -2,6 +2,10 @@ # Makefile for x86 specific library files. #
+ifdef CONFIG_FUNCTION_TRACER +CFLAGS_REMOVE_string_32.o = -pg +endif + inat_tables_script = $(srctree)/arch/x86/tools/gen-insn-attr-x86.awk inat_tables_maps = $(srctree)/arch/x86/lib/x86-opcode-map.txt quiet_cmd_inat_tables = GEN $@ -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux
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