Link error on Fedora 45, gcc 16.1.1: "relocation truncated to fit: R_X86_64_PC32 against `rodata`" and "`.text`"

[DrDaveD]

On Fedora 44 and rawhide (a.k.a 45) with x86_64 architecture and gcc 16.1.1, trying to compile proot v5.4.0 from source ends with the following errors:

  LD	loader/loader
loader/loader.o: in function `_start':
/proot/src/./loader/loader.c:131:(.text+0x23): relocation truncated to fit: R_X86_64_PC32 against `.rodata'
/proot/src/./loader/loader.c:218:(.text+0xc8): relocation truncated to fit: R_X86_64_PC32 against `.rodata'
loader/loader.o:(.rodata+0x0): relocation truncated to fit: R_X86_64_PC32 against `.text'
loader/loader.o:(.rodata+0x4): relocation truncated to fit: R_X86_64_PC32 against `.text'
loader/loader.o:(.rodata+0x8): relocation truncated to fit: R_X86_64_PC32 against `.text'
loader/loader.o:(.rodata+0xc): relocation truncated to fit: R_X86_64_PC32 against `.text'
loader/loader.o:(.rodata+0x10): relocation truncated to fit: R_X86_64_PC32 against `.text'
loader/loader.o:(.rodata+0x14): relocation truncated to fit: R_X86_64_PC32 against `.text'
loader/loader.o:(.rodata+0x18): relocation truncated to fit: R_X86_64_PC32 against `.text'
loader/loader.o:(.rodata+0x1c): relocation truncated to fit: R_X86_64_PC32 against `.text'
loader/loader.o:(.rodata+0x20): additional relocation overflows omitted from the output
collect2: error: ld returned 1 exit status
make: *** [GNUmakefile:273: loader/loader] Error 1
make: Leaving directory '/proot/src'

The easiest way to reproduce is to start a docker container on fedora:45 on an x86_64 host and do the following commands:

# dnf install -y gcc make libtalloc-devel git 
# git clone https://github.com/proot-me/proot.git
# cd proot
# git checkout v5.4.0
# make -C src proot

I have tried to figure out a solution but so far have only succeeded in getting rid of the .text section errors. That was done by editing GNUmakefile to add -mcmodel=large to LOADER_CFLAGS:

git diff src/GNUmakefile
diff --git a/src/GNUmakefile b/src/GNUmakefile
index 168a044..9d429d3 100644
--- a/src/GNUmakefile
+++ b/src/GNUmakefile
@@ -246,7 +246,7 @@ LOADER$1_OBJECTS = loader/loader$1.o loader/assembly$1.o
 $(eval $(call define_from_arch.h,$1,LOADER_ARCH_CFLAGS))
 $(eval $(call define_from_arch.h,$1,LOADER_ADDRESS))

-LOADER_CFLAGS$1  += -fPIC -ffreestanding $(LOADER_ARCH_CFLAGS$1)
+LOADER_CFLAGS$1  += -mcmodel=large -fPIC -ffreestanding $(LOADER_ARCH_CFLAGS$1)
 LOADER_LDFLAGS$1 += -static -nostdlib -Wl$(BUILD_ID_NONE),-Ttext=$(LOADER_ADDRESS$1),-z,noexecstack

 loader/loader$1.o: loader/loader.c

[DrDaveD]

I found that this doesn't fail on the official fedora 44 container from quay.io/fedora/fedora-bootc:44, although the docker.io/fedora:44 container does fail in the same way. It fails for fedora 45 from both sources. This is because the docker.io/fedora:44 container is configured for f45 packages. It has an enabled rawhide repo, but the fedora and fedora-updates repos are disabled, and for some mysterious reason it defaults $releasever to 45. Reversing the enabled flag on those 3 and doing echo 44 >/etc/dnf/vars/releasever makes it behave like the quay.io container and succeed the compile.

I tried comparing package versions to see if I could narrow down which package makes the difference, but it's very hard to tell because there are so many packages. They do have the same version of gcc, 16.1.1, although one has f44 and one has f45 in the name. I tried starting from 44 and selectively updating glibc and gcc to the f45 versions, but that didn't cause it to fail. After doing a generic dnf update --enablerepo=rawhide it did fail, but that was still such a long list of different packages that I gave up on narrowing it down further, especially since it isn't clear if knowing which package makes the difference would help find a real solution.