[Bug 250992] Binaries produced by clang -pg on x86-64 always crash in ld-elf.so.1

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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=250992

            Bug ID: 250992
           Summary: Binaries produced by clang -pg on x86-64 always crash
                    in ld-elf.so.1
           Product: Base System
           Version: 12.2-RELEASE
          Hardware: Any
                OS: Any
            Status: New
          Severity: Affects Only Me
          Priority: ---
         Component: bin
          Assignee: bugs at FreeBSD.org
          Reporter: oleg.derevenetz at gmail.com

Consider the following program (test.c):

$ cat test.c
#include <stdio.h>

int main()
{
    printf("OK\n");
}

When built using the following command:

$ clang -pg test.c

the following binary is produced:

$ file a.out
a.out: ELF 64-bit LSB executable, x86-64, version 1 (FreeBSD), statically
linked, interpreter /libexec/ld-elf.so.1, for FreeBSD 12.2, FreeBSD-style, with
debug_info, not stripped

(note the "interpreter /libexec/ld-elf.so.1" part).

Once launched, it crashes inside ld-elf.so.1 with SIGSEGV:

$ lldb a.out
(lldb) target create "a.out"
Current executable set to '/usr/home/oleg/tmp/pg/a.out' (x86_64).
(lldb) run
Process 872 launching
Process 872 launched: '/usr/home/oleg/tmp/pg/a.out' (x86_64)
Process 872 stopped
* thread #1, name = 'a.out', stop reason = signal SIGSEGV: invalid address
(fault address: 0x0)
    frame #0: 0x00000008002a3ab0
->  0x8002a3ab0: movq   (%r15), %rdx
    0x8002a3ab3: cmpq   $0x6fffffef, %rdx         ; imm = 0x6FFFFFEF
    0x8002a3aba: jg     0x8002a3b10
    0x8002a3abc: cmpq   $0x21, %rdx
(lldb) disassemble
->  0x8002a3ab0: movq   (%r15), %rdx
    0x8002a3ab3: cmpq   $0x6fffffef, %rdx         ; imm = 0x6FFFFFEF
    0x8002a3aba: jg     0x8002a3b10
    0x8002a3abc: cmpq   $0x21, %rdx
    0x8002a3ac0: ja     0x8002a3ba6
    0x8002a3ac6: movslq (%r12,%rdx,4), %rax
    0x8002a3aca: addq   %r12, %rax
    0x8002a3acd: jmpq   *%rax
(lldb)

Disassembled code above is apparently from ld-elf.so.1/_rtld_is_dlopened.

However, if the following command is used for the build:

$ clang -pg -static test.c

the following binary is produced:

$ file a.out
a.out: ELF 64-bit LSB executable, x86-64, version 1 (FreeBSD), statically
linked, for FreeBSD 12.2, FreeBSD-style, with debug_info, not stripped

(note the absence of "interpreter ..." part). This binary runs just fine:

$ lldb a.out
(lldb) target create "a.out"
Current executable set to '/usr/home/oleg/tmp/pg/a.out' (x86_64).
(lldb) run
Process 914 launching
Process 914 launched: '/usr/home/oleg/tmp/pg/a.out' (x86_64)
OK
Process 914 exited with status = 0 (0x00000000)
(lldb)

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