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[PATCH v3 09/27] linux-user/hppa: Document non-use of setup_sigtramp
From: |
Richard Henderson |
Subject: |
[PATCH v3 09/27] linux-user/hppa: Document non-use of setup_sigtramp |
Date: |
Fri, 24 Sep 2021 12:59:08 -0400 |
We cannot use a raw sigtramp page for hppa,
but must wait for full vdso support.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
linux-user/hppa/target_signal.h | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/linux-user/hppa/target_signal.h b/linux-user/hppa/target_signal.h
index 7f525362e9..d558119ee7 100644
--- a/linux-user/hppa/target_signal.h
+++ b/linux-user/hppa/target_signal.h
@@ -71,4 +71,18 @@ typedef struct target_sigaltstack {
/* mask for all SS_xxx flags */
#define TARGET_SS_FLAG_BITS TARGET_SS_AUTODISARM
+/*
+ * We cannot use a bare sigtramp page for hppa-linux.
+ *
+ * Unlike other guests where we use the instructions at PC to validate
+ * an offset from SP, the hppa libgcc signal frame fallback unwinding uses
+ * the PC address itself to find the frame. This is due to the fact that
+ * the hppa grows the stack upward, and the frame is of unknown size.
+ *
+ * TODO: We should be able to use a VDSO to address this, by providing
+ * proper unwind info for the sigtramp code, at which point the fallback
+ * unwinder will not be used.
+ */
+#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 0
+
#endif /* HPPA_TARGET_SIGNAL_H */
--
2.25.1
- [PATCH v3 07/27] linux-user/cris: Implement setup_sigtramp, (continued)
- [PATCH v3 07/27] linux-user/cris: Implement setup_sigtramp, Richard Henderson, 2021/09/24
- [PATCH v3 13/27] linux-user/microblaze: Implement setup_sigtramp, Richard Henderson, 2021/09/24
- [PATCH v3 04/27] linux-user/arm: Drop "_v2" from symbols in signal.c, Richard Henderson, 2021/09/24
- [PATCH v3 02/27] linux-user/aarch64: Implement setup_sigtramp, Richard Henderson, 2021/09/24
- [PATCH v3 03/27] linux-user/arm: Drop v1 signal frames, Richard Henderson, 2021/09/24
- [PATCH v3 06/27] linux-user/alpha: Implement setup_sigtramp, Richard Henderson, 2021/09/24
- [PATCH v3 08/27] linux-user/hexagon: Implement setup_sigtramp, Richard Henderson, 2021/09/24
- [PATCH v3 11/27] linux-user/x86_64: Raise SIGSEGV if SA_RESTORER not set, Richard Henderson, 2021/09/24
- [PATCH v3 09/27] linux-user/hppa: Document non-use of setup_sigtramp,
Richard Henderson <=
- [PATCH v3 10/27] linux-user/i386: Implement setup_sigtramp, Richard Henderson, 2021/09/24
- [PATCH v3 16/27] linux-user/nios2: Properly emulate EXCP_TRAP, Richard Henderson, 2021/09/24
- [PATCH v3 15/27] linux-user/mips: Implement setup_sigtramp, Richard Henderson, 2021/09/24
- [PATCH v3 12/27] linux-user/m68k: Implement setup_sigtramp, Richard Henderson, 2021/09/24
- [PATCH v3 14/27] linux-user/mips: Tidy install_sigtramp, Richard Henderson, 2021/09/24