linux/arch/arm/kernel
Nathan Chancellor c39866f268 arm/build: Always handle .ARM.exidx and .ARM.extab sections
After turning on warnings for orphan section placement, enabling
CONFIG_UNWINDER_FRAME_POINTER instead of CONFIG_UNWINDER_ARM causes
thousands of warnings when clang + ld.lld are used:

$ scripts/config --file arch/arm/configs/multi_v7_defconfig \
                 -d CONFIG_UNWINDER_ARM \
                 -e CONFIG_UNWINDER_FRAME_POINTER
$ make -skj"$(nproc)" ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- LLVM=1 defconfig zImage
ld.lld: warning: init/built-in.a(main.o):(.ARM.extab) is being placed in '.ARM.extab'
ld.lld: warning: init/built-in.a(main.o):(.ARM.extab.init.text) is being placed in '.ARM.extab.init.text'
ld.lld: warning: init/built-in.a(main.o):(.ARM.extab.ref.text) is being placed in '.ARM.extab.ref.text'
ld.lld: warning: init/built-in.a(do_mounts.o):(.ARM.extab.init.text) is being placed in '.ARM.extab.init.text'
ld.lld: warning: init/built-in.a(do_mounts.o):(.ARM.extab) is being placed in '.ARM.extab'
ld.lld: warning: init/built-in.a(do_mounts_rd.o):(.ARM.extab.init.text) is being placed in '.ARM.extab.init.text'
ld.lld: warning: init/built-in.a(do_mounts_rd.o):(.ARM.extab) is being placed in '.ARM.extab'
ld.lld: warning: init/built-in.a(do_mounts_initrd.o):(.ARM.extab.init.text) is being placed in '.ARM.extab.init.text'
ld.lld: warning: init/built-in.a(initramfs.o):(.ARM.extab.init.text) is being placed in '.ARM.extab.init.text'
ld.lld: warning: init/built-in.a(initramfs.o):(.ARM.extab) is being placed in '.ARM.extab'
ld.lld: warning: init/built-in.a(calibrate.o):(.ARM.extab.init.text) is being placed in '.ARM.extab.init.text'
ld.lld: warning: init/built-in.a(calibrate.o):(.ARM.extab) is being placed in '.ARM.extab'

These sections are handled by the ARM_UNWIND_SECTIONS define, which is
only added to the list of sections when CONFIG_ARM_UNWIND is set.
CONFIG_ARM_UNWIND is a hidden symbol that is only selected when
CONFIG_UNWINDER_ARM is set so CONFIG_UNWINDER_FRAME_POINTER never
handles these sections. According to the help text of
CONFIG_UNWINDER_ARM, these sections should be discarded so that the
kernel image size is not affected.

Fixes: 5a17850e25 ("arm/build: Warn on orphan section placement")
Link: https://github.com/ClangBuiltLinux/linux/issues/1152
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Review-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
[kees: Made the discard slightly more specific]
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200928224854.3224862-1-natechancellor@gmail.com
2020-10-27 11:32:21 -07:00
..
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
arch_timer.c ARM: 8913/1: arch_timer: include <asm/arch_timer.h> 2019-10-27 21:14:43 +00:00
armksyms.c crypto: lib/sha1 - remove unnecessary includes of linux/cryptohash.h 2020-05-08 15:32:17 +10:00
asm-offsets.c Raise gcc version requirement to 4.9 2020-07-08 10:48:35 -07:00
atags_compat.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
atags_parse.c initrd: remove support for multiple floppies 2020-07-30 08:22:33 +02:00
atags_proc.c ARM: 8973/1: Add missing newline terminator to kernel message 2020-05-07 20:53:10 +01:00
atags.h ARM: mark setup_machine_tags() stub as __init __noreturn 2019-05-14 19:52:48 -07:00
bios32.c ARM/PCI: Remove unused fields from struct hw_pci 2020-09-18 22:39:09 +01:00
bugs.c treewide: fix typos of SPDX-License-Identifier 2019-06-01 18:29:58 +02:00
cpuidle.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
crash_dump.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
debug.S ARM: 9005/1: debug: Select flow control for all debug UARTs 2020-09-15 14:35:28 +01:00
devtree.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
dma-isa.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
dma.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
early_printk.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
efi.c mm/pgtable: drop pgtable_t variable from pte_fn_t functions 2019-07-12 11:05:46 -07:00
elf.c arm32/64/elf: Split READ_IMPLIES_EXEC from executable PT_GNU_STACK 2020-04-20 19:42:19 +02:00
entry-armv.S ARM: uaccess: consolidate uaccess asm to asm/uaccess-asm.h 2020-05-03 17:30:24 +01:00
entry-common.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
entry-ftrace.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
entry-header.S ARM: uaccess: consolidate uaccess asm to asm/uaccess-asm.h 2020-05-03 17:30:24 +01:00
entry-v7m.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
fiq.c arm: fix the flush_icache_range arguments in set_fiq_handler 2020-06-08 11:05:57 -07:00
fiqasm.S ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ 2014-07-18 12:29:04 +01:00
ftrace.c maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
head-common.S ARM: 8914/1: NOMMU: Fix exc_ret for XIP 2019-10-10 22:23:20 +01:00
head-inflate-data.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
head-nommu.S ARM: 8914/1: NOMMU: Fix exc_ret for XIP 2019-10-10 22:23:20 +01:00
head.S mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
hibernate.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 194 2019-05-30 11:29:22 -07:00
hw_breakpoint.c ARM: 8997/2: hw_breakpoint: Handle inexact watchpoint addresses 2020-09-15 14:35:24 +01:00
hyp-stub.S arm: Remove the ability to set HYP vectors outside of the decompressor 2020-03-24 10:56:05 +00:00
insn.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
io.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
irq.c ARM: Remove custom IRQ stat accounting 2020-09-17 16:37:28 +01:00
isa.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
iwmmxt.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
jump_label.c jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
kgdb.c maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
machine_kexec.c mm: remove unneeded includes of <asm/pgalloc.h> 2020-08-07 11:33:26 -07:00
Makefile Linux 5.5-rc1 2019-12-10 10:11:00 +01:00
module-plts.c ARM: 8910/1: fix missing declartion of module_frob_arch_sections 2019-10-27 21:14:38 +00:00
module.c mm: don't include asm/pgtable.h if linux/mm.h is already included 2020-06-09 09:39:13 -07:00
opcodes.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
paravirt.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
patch.c arm/patch: Fix !MMU compile 2020-02-11 12:56:27 +01:00
perf_callchain.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
perf_event_v6.c arm_pmu: Tidy up clear_event_idx call backs 2018-07-10 18:19:02 +01:00
perf_event_v7.c ARM: 8873/1: perf: cleanup cppcheck shifting warning 2019-08-23 11:38:46 +01:00
perf_event_xscale.c arm_pmu: Tidy up clear_event_idx call backs 2018-07-10 18:19:02 +01:00
perf_regs.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pj4-cp0.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
process.c Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-09 13:33:54 -07:00
psci_smp.c ARM: 8919/1: make unexported functions static 2019-10-31 16:58:52 +00:00
ptrace.c arm: switch to ->regset_get() 2020-07-27 14:31:09 -04:00
reboot.c ARM: Use reboot_cpu instead of hardcoding it to 0 2020-03-25 12:59:33 +01:00
reboot.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
relocate_kernel.S ARM: 8962/1: kexec: drop invalid assembly argument 2020-03-12 11:29:02 +00:00
return_address.c ARM: 8918/2: only build return_address() if needed 2019-11-15 22:21:07 +00:00
setup.c arch, drivers: replace for_each_membock() with for_each_mem_range() 2020-10-13 18:38:35 -07:00
signal.c tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume() 2020-10-17 15:04:36 -06:00
signal.h ARM: 8920/1: share get_signal_page from signal.c to process.c 2019-10-31 16:58:53 +00:00
sigreturn_codes.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
sleep.S ARM: 8847/1: pm: fix HYP/SVC mode mismatch when MCPM is used 2019-02-26 11:32:54 +00:00
smccc-call.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
smp_scu.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
smp_tlb.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
smp_twd.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
smp.c ARM: Handle no IPI being registered in show_ipi_list() 2020-09-28 11:32:04 +01:00
stacktrace.c ARM: 8992/1: Fix unwind_frame for clang-built kernels 2020-07-21 16:33:40 +01:00
suspend.c mm: remove unneeded includes of <asm/pgalloc.h> 2020-08-07 11:33:26 -07:00
swp_emulate.c mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
sys_arm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
sys_oabi-compat.c ARM: compat: remove KERNEL_DS usage in sys_oabi_epoll_ctl() 2020-04-21 17:49:30 +01:00
tcm.c ARM: 8925/1: tcm: include <asm/tcm.h> for missing declarations 2019-10-31 16:58:56 +00:00
thumbee.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
time.c ARM/time: Replace <linux/clk-provider.h> by <linux/of_clk.h> 2020-05-15 22:54:57 +02:00
topology.c ARM, sched/topology: Revert back to default scheduler topology 2020-08-19 10:49:47 +02:00
traps.c maccess: make get_kernel_nofault() check for minimal type compatibility 2020-06-18 12:10:37 -07:00
unwind.c arm: add loglvl to unwind_backtrace() 2020-06-09 09:39:10 -07:00
v7m.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
vdso.c ARM: 8987/1: VDSO: Fix incorrect clock_gettime64 2020-07-21 16:32:55 +01:00
vmlinux-xip.lds.S arm/build: Assert for unwanted sections 2020-09-01 10:03:18 +02:00
vmlinux.lds.S arm/build: Always handle .ARM.exidx and .ARM.extab sections 2020-10-27 11:32:21 -07:00
xscale-cp0.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00