This emits a new file, .tmp_vmlinux.ranges, which maps address
range/size pairs in vmlinux to the object files which make them up,
e.g., in part:
0x0000000000000000 0x30 arch/x86/kernel/cpu/common.o
0x0000000000001000 0x1000 arch/x86/events/intel/ds.o
0x0000000000002000 0x4000 arch/x86/kernel/irq_64.o
0x0000000000006000 0x5000 arch/x86/kernel/process.o
0x000000000000b000 0x1000 arch/x86/kernel/cpu/common.o
0x000000000000c000 0x5000 arch/x86/mm/cpu_entry_area.o
0x0000000000011000 0x10 arch/x86/kernel/espfix_64.o
0x0000000000011010 0x2 arch/x86/kernel/cpu/common.o
[...]
In my simple tests this seems to work with clang too, but if I'm not
sure how stable the format of clang's linker mapfiles is: if it turns
out not to work in some versions, the mapfile-massaging awk script added
here might need some adjustment.
Signed-off-by: Nick Alcock <nick.alcock@xxxxxxxxxx>
Reviewed-by: Kris Van Hees <kris.van.hees@xxxxxxxxxx>
---
Notes:
v6: use ${wl} where appropriate to avoid failure on UML
scripts/link-vmlinux.sh | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 918470d768e9..287a2b2c4d46 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -101,7 +101,7 @@ vmlinux_link()
${ld} ${ldflags} -o ${output} \
${wl}--whole-archive ${objs} ${wl}--no-whole-archive \
${wl}--start-group ${libs} ${wl}--end-group \
- $@ ${ldlibs}
+ ${wl}-Map=.tmp_vmlinux.map $@ ${ldlibs}
}
# generate .BTF typeinfo from DWARF debuginfo
@@ -144,6 +144,19 @@ kallsyms()
{
local kallsymopt;
+ # read the linker map to identify ranges of addresses:
+ # - for each *.o file, report address, size, pathname
+ # - most such lines will have four fields
+ # - but sometimes there is a line break after the first field
+ # - start reading at "Linker script and memory map"
+ # - stop reading at ".brk"
+ ${AWK} '
+ /\.o$/ && start==1 { print $(NF-2), $(NF-1), $NF }
+ /^Linker script and memory map/ { start = 1 }
+ /^\.brk/ { exit(0) }
+ ' .tmp_vmlinux.map | sort > .tmp_vmlinux.ranges
+
+ # get kallsyms options
if is_enabled CONFIG_KALLSYMS_ALL; then
kallsymopt="${kallsymopt} --all-symbols"
fi
--
2.38.0.266.g481848f278
