Segmentation fault, when running compiled LLVM IR

Question

EDIT: I got it working by using ld -o output main.o -L /lib/gcc/x86_64-linux-gnu /lib/x86_64-linux-gnu/crti.o /lib/x86_64-linux-gnu/crtn.o /lib/x86_64-linux-gnu/crt1.o -dynamic-linker /lib64/ld-linux-x86-64.so.2 -lc instead of ld -o output main.o -e main. It seems that these files are necessary to link to successfully run the executable.

I have this simple LLVM IR code, just returning as exit code "15", btw. I use LLVM 17:

; ModuleID = 'main.ll'
source_filename = "main"

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none)
define i32 @main() local_unnamed_addr #0 {
main:
  ret i32 15
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(none) }

I turn the LLVM IR into a .o file, using this command:

llc-17 -filetype=obj main.ll -o main.o

Finally linking the main.o file, using (I also tried ld.lld):

ld -o output main.o -e main

If I run the output (./output), then I get a Segmentation fault error.

This might help:

Output of objdump -D main.o:

main.o:     file format elf64-x86-64


Disassembly of section .text:

0000000000000000 <main>:
   0:   b8 0f 00 00 00          mov    $0xf,%eax
   5:   c3                      ret    

Output of file output:

output: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, not stripped

I also tried debugging using gdb, as followed: gdb ./output, (gdb) run, output:

Starting program: /.../output 

Program received signal SIGSEGV, Segmentation fault.
0x0000000000000001 in ?? ()

then bt (backtrace):

#0  0x0000000000000001 in ?? ()
#1  0x00007fffffffdce6 in ?? ()
#2  0x0000000000000000 in ?? ()

and also info registers:

rax            0xf                 15
rbx            0x0                 0
rcx            0x0                 0
rdx            0x0                 0
rsi            0x0                 0
rdi            0x0                 0
rbp            0x0                 0x0
rsp            0x7fffffffd8d8      0x7fffffffd8d8
r8             0x0                 0
r9             0x0                 0
r10            0x0                 0
r11            0x0                 0
r12            0x0                 0
r13            0x0                 0
r14            0x0                 0
r15            0x0                 0
--Type <RET> for more, q to quit, c to continue without paging--c
rip            0x1                 0x1
eflags         0x10202             [ IF RF ]
cs             0x33                51
ss             0x2b                43
ds             0x0                 0
es             0x0                 0
fs             0x0                 0
gs             0x0                 0
k0             0x0                 0
k1             0x0                 0
k2             0x0                 0
k3             0x0                 0
k4             0x0                 0
k5             0x0                 0
k6             0x0                 0
k7             0x0                 0

Answer 1

I got it working by using ld -o output main.o -L /lib/gcc/x86_64-linux-gnu /lib/x86_64-linux-gnu/crti.o /lib/x86_64-linux-gnu/crtn.o /lib/x86_64-linux-gnu/crt1.o -dynamic-linker /lib64/ld-linux-x86-64.so.2 -lc instead of ld -o output main.o -e main. It seems that these files are necessary to link to successfully run the executable.