From 6fef087d0d37ba7dba8f3d75566eb4c256cd6742 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 7 Jul 2021 18:07:38 -0700 Subject: [PATCH] hexagon: handle {,SOFT}IRQENTRY_TEXT in linker script 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 Reviewed-by: Nick Desaulniers Acked-by: Brian Cain Cc: Oliver Glitta Cc: Vlastimil Babka Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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