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-rw-r--r--arch/riscv/kernel/vdso/Makefile6
-rw-r--r--arch/riscv/kernel/vdso/rt_sigreturn.S10
2 files changed, 12 insertions, 4 deletions
diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
index a842dc034571..43ee881f6c6f 100644
--- a/arch/riscv/kernel/vdso/Makefile
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -69,9 +69,9 @@ CPPFLAGS_$(vdso_lds) += -DHAS_VGETTIMEOFDAY
endif
# Disable -pg to prevent insert call site
-CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
-CFLAGS_REMOVE_getrandom.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
-CFLAGS_REMOVE_hwprobe.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
+CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) $(CC_FLAGS_LTO)
+CFLAGS_REMOVE_getrandom.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) $(CC_FLAGS_LTO)
+CFLAGS_REMOVE_hwprobe.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) $(CC_FLAGS_LTO)
# Force dependency
$(obj)/$(vdso_o): $(obj)/$(vdso_so)
diff --git a/arch/riscv/kernel/vdso/rt_sigreturn.S b/arch/riscv/kernel/vdso/rt_sigreturn.S
index e82987dc3739..d6f96b1abe40 100644
--- a/arch/riscv/kernel/vdso/rt_sigreturn.S
+++ b/arch/riscv/kernel/vdso/rt_sigreturn.S
@@ -7,11 +7,19 @@
#include <asm/unistd.h>
#include <asm/assembler.h>
+/*
+ * WARNING: Do NOT add a CFI landing pad at the start of this function.
+ * Unwinders such as libgcc identify the sigreturn trampoline by matching the
+ * instruction sequence. Adding a landing pad here would break unwinding from
+ * signal handlers.
+ *
+ * This trampoline is used only for signal return and not via an indirect
+ * call/jump from userspace, so adding CFI landing pad is unnecessary.
+ */
.text
SYM_FUNC_START(__vdso_rt_sigreturn)
.cfi_startproc
.cfi_signal_frame
- vdso_lpad
li a7, __NR_rt_sigreturn
ecall
.cfi_endproc