From 51962a9d437f0d580c04cd2c4abc2bd417200da2 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Fri, 13 Oct 2017 15:57:58 -0700 Subject: scripts/kallsyms.c: ignore symbol type 'n' gcc on aarch64 may emit synbols of type 'n' if the kernel is built with '-frecord-gcc-switches'. In most cases, those symbols are reported with nm as 000000000000000e n $d and with objdump as 0000000000000000 l d .GCC.command.line 0000000000000000 .GCC.command.line 000000000000000e l .GCC.command.line 0000000000000000 $d Those symbols are detected in is_arm_mapping_symbol() and ignored. However, if "--prefix-symbols=" is configured as well, the situation is different. For example, in efi/libstub, arm64 images are built with '--prefix-alloc-sections=.init --prefix-symbols=__efistub_'. In combination with '-frecord-gcc-switches', the symbols are now reported by nm as: 000000000000000e n __efistub_$d and by objdump as: 0000000000000000 l d .GCC.command.line 0000000000000000 .GCC.command.line 000000000000000e l .GCC.command.line 0000000000000000 __efistub_$d Those symbols are no longer ignored and included in the base address calculation. This results in a base address of 000000000000000e, which in turn causes kallsyms to abort with kallsyms failure: relative symbol value 0xffffff900800a000 out of range in relative mode The problem is seen in little endian arm64 builds with CONFIG_EFI enabled and with '-frecord-gcc-switches' set in KCFLAGS. Explicitly ignore symbols of type 'n' since those are clearly debug symbols. Link: http://lkml.kernel.org/r/1507136063-3139-1-git-send-email-linux@roeck-us.net Signed-off-by: Guenter Roeck Acked-by: Ard Biesheuvel Cc: Josh Poimboeuf Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- scripts/kallsyms.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts/kallsyms.c') diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c index 5d554419170b..9ee9bf7fd1a2 100644 --- a/scripts/kallsyms.c +++ b/scripts/kallsyms.c @@ -158,7 +158,7 @@ static int read_symbol(FILE *in, struct sym_entry *s) else if (str[0] == '$') return -1; /* exclude debugging symbols */ - else if (stype == 'N') + else if (stype == 'N' || stype == 'n') return -1; /* include the type field in the symbol name, so that it gets -- cgit v1.2.3-59-g8ed1b