Re: [TF-A] Incorrect section attributes with ALLOW_RO_XLAT_TABLES=1 - TF-A

6 Mar 2020


      Hi Masahiro,
That warning is expected. GCC complains about this, since tf_base_xlat_table is not constant and we are asking it to be put in a read-only section (see the REGISTER_XLAT_CONTEXT_RO_BASE_TABLE macro). This is fine since:
*   We only want the base table to be read-only after the tables have been initialized. The only time we change tf_base_xlat_table is when we initialize it, and at that point in the platform setup sequence the MMU is off, so permissions have no effect.
  *   We never write to this with the MMU on (it's the level 1 translation table), so there is no danger of generating MMU faults.
I hope this answers your question.
Thanks
Petre
________________________________
From: TF-A tf-a-bounces@lists.trustedfirmware.org on behalf of Masahiro Yamada via TF-A tf-a@lists.trustedfirmware.org
Sent: 06 March 2020 12:30
To: tf-a@lists.trustedfirmware.org tf-a@lists.trustedfirmware.org
Subject: [TF-A] Incorrect section attributes with ALLOW_RO_XLAT_TABLES=1
Hi.
If I build TF-A with ALLOW_RO_XLAT_TABLES=1,
the base xlat table goes into .rodata section
instead of .bss section.
Then, I see a warning like:
/tmp/ccswitLr.s: Assembler messages:
/tmp/ccswitLr.s:297: Warning: setting incorrect section attributes for .rodata
Is this a know issue?
[Reproduce Command]
make PLAT=fvp CROSS_COMPILE=aarch64-linux-gnu- ALLOW_RO_XLAT_TABLES=1
The full build log is below:
masahiro@pug:~/ref/trusted-firmware-a$ make PLAT=fvp
CROSS_COMPILE=aarch64-linux-gnu- ALLOW_RO_XLAT_TABLES=1
  CC      lib/libfdt/fdt.c
  CC      lib/libfdt/fdt_addresses.c
  CC      lib/libfdt/fdt_empty_tree.c
  CC      lib/libfdt/fdt_ro.c
  CC      lib/libfdt/fdt_rw.c
  CC      lib/libfdt/fdt_strerror.c
  CC      lib/libfdt/fdt_sw.c
  CC      lib/libfdt/fdt_wip.c
  AR      build/fvp/release/lib/libfdt.a
Building fvp
  CC      lib/libc/abort.c
  CC      lib/libc/assert.c
  CC      lib/libc/exit.c
  CC      lib/libc/memchr.c
  CC      lib/libc/memcmp.c
  CC      lib/libc/memcpy.c
  CC      lib/libc/memmove.c
  CC      lib/libc/memrchr.c
  CC      lib/libc/memset.c
  CC      lib/libc/printf.c
  CC      lib/libc/putchar.c
  CC      lib/libc/puts.c
  CC      lib/libc/snprintf.c
  CC      lib/libc/strchr.c
  CC      lib/libc/strcmp.c
  CC      lib/libc/strlcpy.c
  CC      lib/libc/strlen.c
  CC      lib/libc/strncmp.c
  CC      lib/libc/strnlen.c
  CC      lib/libc/strrchr.c
  AS      lib/libc/aarch64/setjmp.S
  AR      build/fvp/release/lib/libc.a
  CC      drivers/arm/smmu/smmu_v3.c
  CC      drivers/arm/sp805/sp805.c
  CC      drivers/delay_timer/delay_timer.c
  CC      drivers/io/io_semihosting.c
  CC      lib/semihosting/semihosting.c
  CC      plat/arm/board/fvp/fvp_bl1_setup.c
  CC      plat/arm/board/fvp/fvp_err.c
  CC      plat/arm/board/fvp/fvp_io_storage.c
  CC      drivers/arm/cci/cci.c
  CC      drivers/delay_timer/generic_delay_timer.c
  CC      drivers/cfi/v2m/v2m_flash.c
  CC      drivers/io/io_fip.c
  CC      drivers/io/io_memmap.c
  CC      drivers/io/io_storage.c
  CC      plat/arm/common/arm_bl1_setup.c
  CC      plat/arm/common/arm_err.c
  CC      plat/arm/common/arm_fconf_io_storage.c
  CC      plat/arm/common/fconf/arm_fconf_io.c
  CC      lib/fconf/fconf.c
  CC      lib/fconf/fconf_dyn_cfg_getter.c
  CC      plat/arm/common/arm_dyn_cfg.c
  CC      plat/arm/common/arm_dyn_cfg_helpers.c
  CC      common/fdt_wrappers.c
  CC      bl1/bl1_main.c
  CC      bl1/aarch64/bl1_arch_setup.c
  CC      bl1/aarch64/bl1_context_mgmt.c
  CC      lib/cpus/errata_report.c
  CC      lib/el3_runtime/aarch64/context_mgmt.c
  CC      plat/common/plat_bl1_common.c
  CC      common/bl_common.c
  CC      common/tf_log.c
  CC      drivers/console/multi_console.c
  CC      plat/common/plat_bl_common.c
  CC      plat/common/plat_log_common.c
  CC      plat/common/aarch64/plat_common.c
  CC      lib/compiler-rt/builtins/popcountdi2.c
  CC      lib/compiler-rt/builtins/popcountsi2.c
  CC      plat/arm/board/fvp/fvp_common.c
  CC      plat/arm/common/arm_common.c
  CC      plat/arm/common/arm_console.c
  CC      lib/xlat_tables_v2/aarch64/xlat_tables_arch.c
  CC      lib/xlat_tables_v2/xlat_tables_context.c
  CC      lib/xlat_tables_v2/xlat_tables_core.c
  CC      lib/xlat_tables_v2/xlat_tables_utils.c
  AS      lib/semihosting/aarch64/semihosting_call.S
  AS      plat/arm/board/fvp/aarch64/fvp_helpers.S
  AS      lib/cpus/aarch64/aem_generic.S
  AS      lib/cpus/aarch64/cortex_a35.S
  AS      lib/cpus/aarch64/cortex_a53.S
  AS      lib/cpus/aarch64/cortex_a57.S
  AS      lib/cpus/aarch64/cortex_a72.S
  AS      lib/cpus/aarch64/cortex_a73.S
  AS      bl1/aarch64/bl1_entrypoint.S
  AS      bl1/aarch64/bl1_exceptions.S
  AS      lib/cpus/aarch64/cpu_helpers.S
  AS      plat/common/aarch64/platform_up_stack.S
  AS      lib/cpus/aarch64/dsu_helpers.S
  AS      lib/el3_runtime/aarch64/context.S
  AS      common/aarch64/debug.S
  AS      lib/aarch64/cache_helpers.S
  AS      lib/aarch64/misc_helpers.S
  AS      plat/common/aarch64/platform_helpers.S
  AS      drivers/arm/pl011/aarch64/pl011_console.S
  AS      plat/arm/board/common/aarch64/board_arm_helpers.S
  AS      plat/arm/common/aarch64/arm_helpers.S
  AS      lib/xlat_tables_v2/aarch64/enable_mmu.S
  PP      bl1/bl1.ld.S
  LD      build/fvp/release/bl1/bl1.elf
  BIN     build/fvp/release/bl1.bin
Built build/fvp/release/bl1.bin successfully
OD      build/fvp/release/bl1/bl1.dump
  CC      drivers/arm/sp805/sp805.c
  CC      drivers/io/io_semihosting.c
  CC      lib/utils/mem_region.c
  CC      lib/semihosting/semihosting.c
  CC      plat/arm/board/fvp/fvp_bl2_setup.c
  CC      plat/arm/board/fvp/fvp_err.c
  CC      plat/arm/board/fvp/fvp_io_storage.c
  CC      plat/arm/common/arm_nor_psci_mem_protect.c
  CC      drivers/arm/tzc/tzc400.c
  CC      plat/arm/board/fvp/fvp_security.c
  CC      plat/arm/common/arm_tzc400.c
  CC      drivers/cfi/v2m/v2m_flash.c
  CC      drivers/delay_timer/delay_timer.c
  CC      drivers/delay_timer/generic_delay_timer.c
  CC      drivers/io/io_fip.c
  CC      drivers/io/io_memmap.c
  CC      drivers/io/io_storage.c
  CC      plat/arm/common/arm_bl2_setup.c
  CC      plat/arm/common/arm_err.c
  CC      plat/arm/common/arm_fconf_io_storage.c
  CC      plat/arm/common/fconf/arm_fconf_io.c
  CC      lib/fconf/fconf.c
  CC      lib/fconf/fconf_dyn_cfg_getter.c
  CC      plat/arm/common/arm_dyn_cfg.c
  CC      plat/arm/common/arm_dyn_cfg_helpers.c
  CC      common/fdt_wrappers.c
  CC      plat/arm/common/aarch64/arm_bl2_mem_params_desc.c
  CC      plat/arm/common/arm_image_load.c
  CC      common/desc_image_load.c
  CC      bl2/bl2_image_load_v2.c
  CC      bl2/bl2_main.c
  CC      bl2/aarch64/bl2_arch_setup.c
  CC      common/bl_common.c
  CC      common/tf_log.c
  CC      drivers/console/multi_console.c
  CC      plat/common/plat_bl_common.c
  CC      plat/common/plat_log_common.c
  CC      plat/common/aarch64/plat_common.c
  CC      lib/compiler-rt/builtins/popcountdi2.c
  CC      lib/compiler-rt/builtins/popcountsi2.c
  CC      plat/arm/board/fvp/fvp_common.c
  CC      plat/arm/common/arm_common.c
  CC      plat/arm/common/arm_console.c
  CC      lib/xlat_tables_v2/aarch64/xlat_tables_arch.c
  CC      lib/xlat_tables_v2/xlat_tables_context.c
  CC      lib/xlat_tables_v2/xlat_tables_core.c
  CC      lib/xlat_tables_v2/xlat_tables_utils.c
  AS      lib/semihosting/aarch64/semihosting_call.S
  AS      lib/locks/exclusive/aarch64/spinlock.S
  AS      plat/common/aarch64/platform_up_stack.S
  AS      common/aarch64/early_exceptions.S
  AS      bl2/aarch64/bl2_entrypoint.S
  AS      common/aarch64/debug.S
  AS      lib/aarch64/cache_helpers.S
  AS      lib/aarch64/misc_helpers.S
  AS      plat/common/aarch64/platform_helpers.S
  AS      drivers/arm/pl011/aarch64/pl011_console.S
  AS      plat/arm/board/common/aarch64/board_arm_helpers.S
  AS      plat/arm/common/aarch64/arm_helpers.S
  AS      lib/xlat_tables_v2/aarch64/enable_mmu.S
  PP      bl2/bl2.ld.S
  LD      build/fvp/release/bl2/bl2.elf
  BIN     build/fvp/release/bl2.bin
Built build/fvp/release/bl2.bin successfully
OD      build/fvp/release/bl2/bl2.dump
  CC      drivers/arm/fvp/fvp_pwrc.c
  CC      drivers/arm/smmu/smmu_v3.c
  CC      drivers/delay_timer/delay_timer.c
  CC      drivers/cfi/v2m/v2m_flash.c
  CC      lib/utils/mem_region.c
  CC      plat/arm/board/fvp/fvp_bl31_setup.c
  CC      plat/arm/board/fvp/fvp_pm.c
  CC      plat/arm/board/fvp/fvp_topology.c
  CC      plat/arm/common/arm_nor_psci_mem_protect.c
  CC      drivers/arm/gic/common/gic_common.c
  CC      drivers/arm/gic/v3/gicv3_main.c
  CC      drivers/arm/gic/v3/gicv3_helpers.c
  CC      plat/common/plat_gicv3.c
  CC      plat/arm/common/arm_gicv3.c
  CC      drivers/arm/gic/v3/gic500.c
  CC      drivers/arm/cci/cci.c
  CC      drivers/arm/tzc/tzc400.c
  CC      plat/arm/board/fvp/fvp_security.c
  CC      plat/arm/common/arm_tzc400.c
  CC      drivers/delay_timer/generic_delay_timer.c
  CC      lib/cpus/aarch64/cpuamu.c
  CC      plat/arm/common/arm_bl31_setup.c
  CC      plat/arm/common/arm_pm.c
  CC      plat/arm/common/arm_topology.c
  CC      plat/common/plat_psci_common.c
  CC      plat/arm/common/aarch64/execution_state_switch.c
  CC      plat/arm/common/arm_sip_svc.c
  CC      lib/pmf/pmf_smc.c
  CC      bl31/bl31_main.c
  CC      bl31/interrupt_mgmt.c
  CC      bl31/bl31_context_mgmt.c
  CC      common/runtime_svc.c
  CC      services/arm_arch_svc/arm_arch_svc_setup.c
  CC      services/std_svc/std_svc_setup.c
  CC      lib/el3_runtime/cpu_data_array.c
  CC      lib/el3_runtime/aarch64/context_mgmt.c
  CC      lib/cpus/errata_report.c
  CC      lib/psci/psci_off.c
  CC      lib/psci/psci_on.c
  CC      lib/psci/psci_suspend.c
  CC      lib/psci/psci_common.c
  CC      lib/psci/psci_main.c
  CC      lib/psci/psci_setup.c
  CC      lib/psci/psci_system_off.c
  CC      lib/psci/psci_mem_protect.c
  CC      lib/locks/bakery/bakery_lock_coherent.c
  CC      lib/psci/psci_stat.c
  CC      lib/pmf/pmf_main.c
  CC      lib/extensions/spe/spe.c
  CC      lib/extensions/amu/aarch64/amu.c
  CC      lib/extensions/sve/sve.c
  CC      common/bl_common.c
  CC      common/tf_log.c
  CC      drivers/console/multi_console.c
  CC      plat/common/plat_bl_common.c
  CC      plat/common/plat_log_common.c
  CC      plat/common/aarch64/plat_common.c
  CC      lib/compiler-rt/builtins/popcountdi2.c
  CC      lib/compiler-rt/builtins/popcountsi2.c
  CC      plat/arm/board/fvp/fvp_common.c
  CC      plat/arm/common/arm_common.c
  CC      plat/arm/common/arm_console.c
  CC      lib/xlat_tables_v2/aarch64/xlat_tables_arch.c
  CC      lib/xlat_tables_v2/xlat_tables_context.c
/tmp/ccswitLr.s: Assembler messages:
/tmp/ccswitLr.s:297: Warning: setting incorrect section attributes for .rodata
  CC      lib/xlat_tables_v2/xlat_tables_core.c
  CC      lib/xlat_tables_v2/xlat_tables_utils.c
  AS      plat/arm/board/fvp/aarch64/fvp_helpers.S
  AS      lib/cpus/aarch64/aem_generic.S
  AS      lib/cpus/aarch64/cortex_a35.S
  AS      lib/cpus/aarch64/cortex_a53.S
  AS      lib/cpus/aarch64/cortex_a57.S
  AS      lib/cpus/aarch64/cortex_a72.S
  AS      lib/cpus/aarch64/cortex_a73.S
  AS      lib/cpus/aarch64/cpuamu_helpers.S
  AS      bl31/aarch64/bl31_entrypoint.S
  AS      bl31/aarch64/crash_reporting.S
  AS      bl31/aarch64/ea_delegate.S
  AS      bl31/aarch64/runtime_exceptions.S
  AS      lib/cpus/aarch64/dsu_helpers.S
  AS      plat/common/aarch64/platform_mp_stack.S
  AS      lib/el3_runtime/aarch64/cpu_data.S
  AS      lib/cpus/aarch64/cpu_helpers.S
  AS      lib/locks/exclusive/aarch64/spinlock.S
  AS      lib/psci/aarch64/psci_helpers.S
  AS      lib/el3_runtime/aarch64/context.S
  AS      lib/extensions/amu/aarch64/amu_helpers.S
  AS      lib/cpus/aarch64/wa_cve_2017_5715_bpiall.S
  AS      lib/cpus/aarch64/wa_cve_2017_5715_mmu.S
  AS      common/aarch64/debug.S
  AS      lib/aarch64/cache_helpers.S
  AS      lib/aarch64/misc_helpers.S
  AS      plat/common/aarch64/platform_helpers.S
  AS      drivers/arm/pl011/aarch64/pl011_console.S
  AS      plat/arm/board/common/aarch64/board_arm_helpers.S
  AS      plat/arm/common/aarch64/arm_helpers.S
  AS      lib/xlat_tables_v2/aarch64/enable_mmu.S
  PP      bl31/bl31.ld.S
  LD      build/fvp/release/bl31/bl31.elf
  BIN     build/fvp/release/bl31.bin
Built build/fvp/release/bl31.bin successfully
OD      build/fvp/release/bl31/bl31.dump
  CC      plat/arm/board/fvp/fvp_bl2u_setup.c
  CC      drivers/arm/tzc/tzc400.c
  CC      plat/arm/board/fvp/fvp_security.c
  CC      plat/arm/common/arm_tzc400.c
  CC      drivers/delay_timer/delay_timer.c
  CC      drivers/delay_timer/generic_delay_timer.c
  CC      plat/arm/common/arm_bl2u_setup.c
  CC      bl2u/bl2u_main.c
  CC      common/bl_common.c
  CC      common/tf_log.c
  CC      drivers/console/multi_console.c
  CC      plat/common/plat_bl_common.c
  CC      plat/common/plat_log_common.c
  CC      plat/common/aarch64/plat_common.c
  CC      lib/compiler-rt/builtins/popcountdi2.c
  CC      lib/compiler-rt/builtins/popcountsi2.c
  CC      plat/arm/board/fvp/fvp_common.c
  CC      plat/arm/common/arm_common.c
  CC      plat/arm/common/arm_console.c
  CC      lib/xlat_tables_v2/aarch64/xlat_tables_arch.c
  CC      lib/xlat_tables_v2/xlat_tables_context.c
  CC      lib/xlat_tables_v2/xlat_tables_core.c
  CC      lib/xlat_tables_v2/xlat_tables_utils.c
  AS      bl2u/aarch64/bl2u_entrypoint.S
  AS      plat/common/aarch64/platform_up_stack.S
  AS      common/aarch64/early_exceptions.S
  AS      common/aarch64/debug.S
  AS      lib/aarch64/cache_helpers.S
  AS      lib/aarch64/misc_helpers.S
  AS      plat/common/aarch64/platform_helpers.S
  AS      drivers/arm/pl011/aarch64/pl011_console.S
  AS      plat/arm/board/common/aarch64/board_arm_helpers.S
  AS      plat/arm/common/aarch64/arm_helpers.S
  AS      lib/xlat_tables_v2/aarch64/enable_mmu.S
  PP      bl2u/bl2u.ld.S
  LD      build/fvp/release/bl2u/bl2u.elf
  BIN     build/fvp/release/bl2u.bin
Built build/fvp/release/bl2u.bin successfully
OD      build/fvp/release/bl2u/bl2u.dump
  CPP     plat/arm/board/fvp/fdts/fvp_fw_config.dts
  DTC     plat/arm/board/fvp/fdts/fvp_fw_config.dts
  CPP     plat/arm/board/fvp/fdts/fvp_soc_fw_config.dts
  DTC     plat/arm/board/fvp/fdts/fvp_soc_fw_config.dts
  CPP     plat/arm/board/fvp/fdts/fvp_nt_fw_config.dts
  DTC     plat/arm/board/fvp/fdts/fvp_nt_fw_config.dts
  CPP     fdts/fvp-base-gicv3-psci.dts
  DTC     fdts/fvp-base-gicv3-psci.dts
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:215.20-220.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/flash@0,00000000:
simple-bus unit address format error, expected "0"
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:221.19-224.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/vram@2,00000000:
simple-bus unit address format error, expected "200000000"
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:225.23-229.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/ethernet@2,02000000:
simple-bus unit address format error, expected "202000000"
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:230.26-235.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/clk24mhz: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:236.30-241.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/refclk1mhz: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:242.32-247.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/refclk32khz: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:248.21-370.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/iofpga@3,00000000:
simple-bus unit address format error, expected "300000000"
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:371.33-377.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/fixedregulator: missing
or empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:381.21-387.6:
Warning (simple_bus_reg): /smb@0,0/motherboard/mcc/osc: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:388.12-391.6:
Warning (simple_bus_reg): /smb@0,0/motherboard/mcc/muxfpga: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:392.12-395.6:
Warning (simple_bus_reg): /smb@0,0/motherboard/mcc/dvimode: missing or
empty reg/ranges property
--
Best Regards
Masahiro Yamada
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