Hi Alex, On 21 August 2018 at 13:26, Alexander Graf <ag...@suse.de> wrote: > > > On 21.08.18 19:30, Simon Glass wrote: >> Hi Alex, >> >> On 20 August 2018 at 06:23, Alexander Graf <ag...@suse.de> wrote: >>> >>> On 08/17/2018 02:49 PM, Simon Glass wrote: >>>> >>>> Hi, >>>> >>>> On 9 August 2018 at 23:45, Bin Meng <bmeng...@gmail.com> wrote: >>>>> >>>>> Hi Alex, >>>>> >>>>> On Wed, Aug 8, 2018 at 1:16 AM, Alexander Graf <ag...@suse.de> wrote: >>>>>> >>>>>> >>>>>>> Am 07.08.2018 um 18:12 schrieb Simon Glass <s...@chromium.org>: >>>>>>> >>>>>>> Hi Alex, >>>>>>> >>>>>>>> On 11 June 2018 at 23:48, Alexander Graf <ag...@suse.de> wrote: >>>>>>>> Some times gcc may generate data that is then used within code that may >>>>>>>> be part of an efi runtime section. That data could be jump tables, >>>>>>>> constants or strings. >>>>>>>> >>>>>>>> In order to make sure we catch these, we need to ensure that gcc emits >>>>>>>> them into a section that we can relocate together with all the other >>>>>>>> efi runtime bits. This only works if the -ffunction-sections and >>>>>>>> -fdata-sections flags are passed and the efi runtime functions are >>>>>>>> in a section that starts with ".text". >>>>>>>> >>>>>>>> Up to now we had all efi runtime bits in sections that did not >>>>>>>> interfere with the normal section naming scheme, but this forces >>>>>>>> us to do so. Hence we need to move the efi_loader text/data/rodata >>>>>>>> sections before the global *(.text*) catch-all section. >>>>>>>> >>>>>>>> With this patch in place, we should hopefully have an easier time >>>>>>>> to extend the efi runtime functionality in the future. >>>>>>>> >>>>>>>> Signed-off-by: Alexander Graf <ag...@suse.de> >>>>>>>> --- >>>>>>>> arch/arm/config.mk | 4 ++-- >>>>>>>> arch/arm/cpu/armv8/u-boot.lds | 24 +++++++++++++-------- >>>>>>>> arch/arm/cpu/u-boot.lds | 36 >>>>>>>> ++++++++++++++++++------------- >>>>>>>> arch/arm/mach-zynq/u-boot.lds | 36 >>>>>>>> ++++++++++++++++++------------- >>>>>>>> arch/riscv/cpu/ax25/u-boot.lds | 26 +++++++++++++--------- >>>>>>>> arch/sandbox/config.mk | 3 +++ >>>>>>>> arch/sandbox/cpu/u-boot.lds | 9 ++++---- >>>>>>>> arch/x86/config.mk | 2 +- >>>>>>>> arch/x86/cpu/u-boot.lds | 32 >>>>>>>> ++++++++++++++------------- >>>>>>>> board/qualcomm/dragonboard410c/u-boot.lds | 17 +++++++++++++-- >>>>>>>> board/qualcomm/dragonboard820c/u-boot.lds | 24 +++++++++++++-------- >>>>>>>> board/ti/am335x/u-boot.lds | 36 >>>>>>>> ++++++++++++++++++------------- >>>>>>>> include/efi_loader.h | 4 ++-- >>>>>>>> 13 files changed, 154 insertions(+), 99 deletions(-) >>>>>>>> >>>>>>> I missed this at the time, probably thinking the subject made it sound >>>>>>> innocuous. There is no 'sandbox:' tag. >>>>>>> >>>>>>> This seems to break sandbox in a pretty strange way: >>>>>>> >>>>>>> gdb --args /tmp/crosfw/sandbox/u-boot -D >>>>>>> GNU gdb (Debian 7.12-6) 7.12.0.20161007-git >>>>>>> Copyright (C) 2016 Free Software Foundation, Inc. >>>>>>> License GPLv3+: GNU GPL version 3 or later >>>>>>> <http://gnu.org/licenses/gpl.html> >>>>>>> This is free software: you are free to change and redistribute it. >>>>>>> There is NO WARRANTY, to the extent permitted by law. Type "show >>>>>>> copying" >>>>>>> and "show warranty" for details. >>>>>>> This GDB was configured as "x86_64-linux-gnu". >>>>>>> Type "show configuration" for configuration details. >>>>>>> For bug reporting instructions, please see: >>>>>>> <http://www.gnu.org/software/gdb/bugs/>. >>>>>>> Find the GDB manual and other documentation resources online at: >>>>>>> <http://www.gnu.org/software/gdb/documentation/>. >>>>>>> For help, type "help". >>>>>>> Type "apropos word" to search for commands related to "word"... >>>>>>> Reading symbols from /tmp/crosfw/sandbox/u-boot...done. >>>>>>> (gdb) r >>>>>>> Starting program: /tmp/crosfw/sandbox/u-boot -D >>>>>>> [Thread debugging using libthread_db enabled] >>>>>>> Using host libthread_db library >>>>>>> "/lib/x86_64-linux-gnu/libthread_db.so.1". >>>>>>> >>>>>>> Program received signal SIGSEGV, Segmentation fault. >>>>>>> 0x0000555555571520 in open@plt () >>>>>>> (gdb) up >>>>>>> #1 0x0000555555571e9a in sandbox_read_fdt_from_file () >>>>>>> at >>>>>>> /home/sjg/c/src/third_party/u-boot/files/arch/sandbox/cpu/cpu.c:264 >>>>>>> 264 fd = os_open(fname, OS_O_RDONLY); >>>>>>> (gdb) print fname >>>>>>> $1 = 0x7ffff7ff0000 "/tmp/crosfw/sandbox/u-boot.dtb" >>>>>>> (gdb) q >>>>>>> >>>>>>> >>>>>>> Also the commit message suggests that this patch changes sandbox to >>>>>>> use --gc-sections, which is not obvious from the subject. I think that >>>>>>> should be a separate commit and in fact it should really be separate >>>>>>> commits for each arch, I think. That might help people notice it... >>>>>>> >>>>>>> I only noticed now since the EFI pull request has landed. >>>>>> >>>>>> Can you try my bss patch really quick? Maybe we're just overwriting gd. >>>>>> >>>>>> Alex >>>>>> >>>>> This patch breaks efi-x86_app_defconfig. The EFI application no longer >>>>> boots. I was testing on top of u-boot/master. >>>>> >>>>> If I do: >>>>> >>>>> diff --git a/arch/x86/config.mk b/arch/x86/config.mk >>>>> index 586e11a..fc119ec 100644 >>>>> --- a/arch/x86/config.mk >>>>> +++ b/arch/x86/config.mk >>>>> @@ -24,7 +24,6 @@ endif >>>>> ifeq ($(IS_32BIT),y) >>>>> PLATFORM_CPPFLAGS += -march=i386 -m32 >>>>> # TODO: These break on x86_64; need to debug further >>>>> -PLATFORM_RELFLAGS += -fdata-sections >>>>> else >>>>> PLATFORM_CPPFLAGS += $(if $(CONFIG_SPL_BUILD),,-fpic) -fno-common -m64 >>>>> endif >>>>> >>>>> Then it boots again. Can you please take a look? >>>>> >>>>> Regards, >>>>> Bin >>>> >>>> Please can we revert the offending patch quickly for the release? I am >>>> not comfortable with the sandbox changes either (data-sections, etc.). >>> >>> I can not reproduce the sandbox breakage (and travis doesn't seem to >>> either, otherwise it would be broken for everyone, no?). Can you give me >>> some guidelines on how to reproduce the failures for you and I'll just fix >>> it? >> >> I would like to revert the sandbox changes at least. I don't want to >> enable -ffunction-sections, for example. > > Could you please explain why? In general I always thought the sandbox > target was meant as debugging aid which allows you to find and debug > bugs more easily. > > I would assume that chances for breakage are higher with function and > data sections, because the linker could remove code it considers dead? > So for a debugging target, I would think it makes sense to have it > enabled rather than disabled.
Yes I think removing dead could could cause problems. But so could not garbage-collecting sections, so it is not a great argument. Sandbox is targeted at building as much code as possible. Ideally every piece of non-arch-specific code should be built with sandbox. Maybe I am being conservative, but I see no reason to enable it for sandbox. I'll try to think of some better reasons and reply if I can. I also feel that it slipped in under the radar with no review. Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
