From 758f33379569d817558a4310c47b42834b8e4e57 Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Tue, 10 Jan 2023 08:24:23 +0100 Subject: [PATCH] tools/nolibc: export environ as a weak symbol on riscv The environ is retrieved from the _start code and is easy to store at this moment. Let's declare the variable weak and store the value into it. By not being static it will be visible to all units. By being weak, if some programs already declared it, they will continue to be able to use it. This was tested on riscv64 both with environ inherited from _start and extracted from envp. Signed-off-by: Willy Tarreau Signed-off-by: Paul E. McKenney --- tools/include/nolibc/arch-riscv.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/include/nolibc/arch-riscv.h b/tools/include/nolibc/arch-riscv.h index c2b5db383d96f..1608e6bd94b97 100644 --- a/tools/include/nolibc/arch-riscv.h +++ b/tools/include/nolibc/arch-riscv.h @@ -170,6 +170,8 @@ struct sys_stat_struct { _arg1; \ }) +char **environ __attribute__((weak)); + /* startup code */ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void) { @@ -183,6 +185,8 @@ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void) "slli a2, a0, "PTRLOG"\n" // envp (a2) = SZREG*argc ... "add a2, a2, "SZREG"\n" // + SZREG (skip null) "add a2,a2,a1\n" // + argv + "lui a3, %hi(environ)\n" // a3 = &environ (high bits) + "sd a2,%lo(environ)(a3)\n" // store envp(a2) into environ "andi sp,a1,-16\n" // sp must be 16-byte aligned "call main\n" // main() returns the status code, we'll exit with it. "li a7, 93\n" // NR_exit == 93 -- 2.30.2