On Fri, 5 Mar 2021 09:58:34 -0700 Simon Glass sjg@chromium.org wrote:
Hi Marek,
On Fri, 5 Mar 2021 at 09:50, Marek Behun marek.behun@nic.cz wrote:
On Fri, 5 Mar 2021 09:39:53 -0700 Simon Glass sjg@chromium.org wrote:
Hi Marek,
On Fri, 5 Mar 2021 at 08:37, Marek Behun marek.behun@nic.cz wrote:
On Fri, 5 Mar 2021 11:00:45 +0800 Bin Meng bmeng.cn@gmail.com wrote:
On Wed, Mar 3, 2021 at 12:13 PM Marek Behún marek.behun@nic.cz wrote:
When building with LTO, the system libc's `errno` variable used in arch/sandbox/cpu/os.c conflicts with U-Boot's `errno` (defined in lib/errno.c) with the following error: .../ld: errno@@GLIBC_PRIVATE: TLS definition in /lib64/libc.so.6 section .tbss mismatches non-TLS reference in /tmp/u-boot.EQlEXz.ltrans0.ltrans.o
Do you know if this is the expected behavior when enabling LTO on the compiler?
I don't, but this is a bug anyway. The symbol clashes with the symbol from glibc. Does somebody know whether the usage of this symbol in os.c does really use glibc's version or U-Boot's one?
It is intended to use glibc's version. In fact I don't think U-Boot should have an errno. We return errors in each case, as does Linux.
The problem is that libc defines errno as a thread-local variable or, in older version, as a macro expading to a function dereference, i.e. #define errno (*__get_threads_errno()) But U-Boot usis the errno symbol defined in include/errno.h as a symbol.
So in order for these two symbols not to clash (in case libc is using thread-local symbol with name errno), we need to rename the U-Boot errno variable's symbol name.
Rename is OK, but can we delete it instead? I really don't think it should be there.
We can't simply delete it. The whole u-boot is using the errno symbol from include/errno.h and if we want the whole u-boot to use libc's symbol we need to code include/errno.h to declare it in the same way as libc, which may be different for different libcs.