Re: [RFC PATCH v2 3/8] tools/nolibc: i386: Implement syscall with 6 arguments

From: Ammar Faizi
Date: Tue Mar 22 2022 - 09:56:56 EST


On 3/22/22 8:54 PM, Ammar Faizi wrote:

Willy, something goes wrong here...

ammarfaizi2@integral2:~/work/linux.work/tools/include/nolibc$ taskset -c 0 gcc -ffreestanding -nostdlib -nostartfiles test.c -o test -lgcc
/usr/bin/ld: /tmp/ccHiYiks.o: warning: relocation against `environ' in read-only section `.text'
/usr/bin/ld: /tmp/ccHiYiks.o: in function `getenv':
test.c:(.text+0x1f76): undefined reference to `environ'
/usr/bin/ld: test.c:(.text+0x1fc3): undefined reference to `environ'
/usr/bin/ld: test.c:(.text+0x1ffc): undefined reference to `environ'
/usr/bin/ld: test.c:(.text+0x2021): undefined reference to `environ'
/usr/bin/ld: test.c:(.text+0x2049): undefined reference to `environ'
/usr/bin/ld: warning: creating DT_TEXTREL in a PIE
collect2: error: ld returned 1 exit status
ammarfaizi2@integral2:~/work/linux.work/tools/include/nolibc$


I suspect it's caused by commit:

commit c970abe796019b3d576fd154a54b94efb35c02b1
Author: Willy Tarreau <w@xxxxxx>
Date:   Mon Mar 21 18:33:08 2022 +0100

    tools/nolibc/stdlib: add a simple getenv() implementation
    This implementation relies on an extern definition of the environ
    variable, that the caller must declare and initialize from envp.
    Signed-off-by: Willy Tarreau <w@xxxxxx>
    Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>

I will take a look deeper on this...

This bug only exists when compiling without optimization.

--
Ammar Faizi