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authorNicholas Piggin <npiggin@gmail.com>2021-06-18 01:51:08 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2021-06-25 00:06:56 +1000
commitf23699c93becd746295aaa506537882a46a62219 (patch)
treeea44289996524915c83e6876b39babbe6a640ff8 /arch/powerpc/kernel/vmlinux.lds.S
parent63e40806eea984f770c992120bbfd71b589ea580 (diff)
downloadlinux-f23699c93becd746295aaa506537882a46a62219.tar.bz2
powerpc/64: allow alternate return locations for soft-masked interrupts
The exception table fixup adjusts a failed page fault's interrupt return location if it was taken at an address specified in the exception table, to a corresponding fixup handler address. Introduce a variation of that idea which adds a fixup table for NMIs and soft-masked asynchronous interrupts. This will be used to protect certain critical sections that are sensitive to being clobbered by interrupts coming in (due to using the same SPRs and/or irq soft-mask state). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-10-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kernel/vmlinux.lds.S')
-rw-r--r--arch/powerpc/kernel/vmlinux.lds.S10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 72fa3c00229a..16c5e13e00c4 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -9,6 +9,14 @@
#define EMITS_PT_NOTE
#define RO_EXCEPTION_TABLE_ALIGN 0
+#define RESTART_TABLE(align) \
+ . = ALIGN(align); \
+ __restart_table : AT(ADDR(__restart_table) - LOAD_OFFSET) { \
+ __start___restart_table = .; \
+ KEEP(*(__restart_table)) \
+ __stop___restart_table = .; \
+ }
+
#include <asm/page.h>
#include <asm-generic/vmlinux.lds.h>
#include <asm/cache.h>
@@ -124,6 +132,8 @@ SECTIONS
RO_DATA(PAGE_SIZE)
#ifdef CONFIG_PPC64
+ RESTART_TABLE(8)
+
. = ALIGN(8);
__stf_entry_barrier_fixup : AT(ADDR(__stf_entry_barrier_fixup) - LOAD_OFFSET) {
__start___stf_entry_barrier_fixup = .;