From: Nathan Chancellor nathan@kernel.org
[ Upstream commit 6fef087d0d37ba7dba8f3d75566eb4c256cd6742 ]
Patch series "hexagon: Fix build error with CONFIG_STACKDEPOT and select CONFIG_ARCH_WANT_LD_ORPHAN_WARN".
This series fixes an error with ARCH=hexagon that was pointed out by the patch "mm/slub: use stackdepot to save stack trace in objects".
The first patch fixes that error by handling the '.irqentry.text' and '.softirqentry.text' sections.
The second patch switches Hexagon over to the common DISCARDS macro, which should have been done when Hexagon was merged into the tree to match commit 023bf6f1b8bf ("linker script: unify usage of discard definition").
The third patch selects CONFIG_ARCH_WANT_LD_ORPHAN_WARN so that something like this does not happen again.
This patch (of 3):
Patch "mm/slub: use stackdepot to save stack trace in objects" in -mm selects CONFIG_STACKDEPOT when CONFIG_STACKTRACE_SUPPORT is selected and CONFIG_STACKDEPOT requires IRQENTRY_TEXT and SOFTIRQENTRY_TEXT to be handled after commit 505a0ef15f96 ("kasan: stackdepot: move filter_irq_stacks() to stackdepot.c") due to the use of the __{,soft}irqentry_text_{start,end} section symbols. If those sections are not handled, the build is broken.
$ make ARCH=hexagon CROSS_COMPILE=hexagon-linux- LLVM=1 LLVM_IAS=1 defconfig all ... ld.lld: error: undefined symbol: __irqentry_text_start
referenced by stackdepot.c stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a referenced by stackdepot.c stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
ld.lld: error: undefined symbol: __irqentry_text_end
referenced by stackdepot.c stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a referenced by stackdepot.c stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
ld.lld: error: undefined symbol: __softirqentry_text_start
referenced by stackdepot.c stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a referenced by stackdepot.c stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
ld.lld: error: undefined symbol: __softirqentry_text_end
referenced by stackdepot.c stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a referenced by stackdepot.c stackdepot.o:(filter_irq_stacks) in archive lib/built-in.a
...
Add these sections to the Hexagon linker script so the build continues to work. ld.lld's orphan section warning would have caught this prior to the -mm commit mentioned above:
ld.lld: warning: kernel/built-in.a(softirq.o):(.softirqentry.text) is being placed in '.softirqentry.text' ld.lld: warning: kernel/built-in.a(softirq.o):(.softirqentry.text) is being placed in '.softirqentry.text' ld.lld: warning: kernel/built-in.a(softirq.o):(.softirqentry.text) is being placed in '.softirqentry.text'
Link: https://lkml.kernel.org/r/20210521011239.1332345-1-nathan@kernel.org Link: https://lkml.kernel.org/r/20210521011239.1332345-2-nathan@kernel.org Link: https://github.com/ClangBuiltLinux/linux/issues/1381 Fixes: 505a0ef15f96 ("kasan: stackdepot: move filter_irq_stacks() to stackdepot.c") Signed-off-by: Nathan Chancellor nathan@kernel.org Reviewed-by: Nick Desaulniers ndesaulniers@google.com Acked-by: Brian Cain bcain@codeaurora.org Cc: Oliver Glitta glittao@gmail.com Cc: Vlastimil Babka vbabka@suse.cz Cc: David Rientjes rientjes@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/hexagon/kernel/vmlinux.lds.S | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/hexagon/kernel/vmlinux.lds.S b/arch/hexagon/kernel/vmlinux.lds.S index 35b18e55eae8..20f19539c5fc 100644 --- a/arch/hexagon/kernel/vmlinux.lds.S +++ b/arch/hexagon/kernel/vmlinux.lds.S @@ -38,6 +38,8 @@ SECTIONS .text : AT(ADDR(.text)) { _text = .; TEXT_TEXT + IRQENTRY_TEXT + SOFTIRQENTRY_TEXT SCHED_TEXT CPUIDLE_TEXT LOCK_TEXT