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From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org, "Alex Bennée" <alex.bennee@linaro.org>,
	laurent@vivier.eu, "Philippe Mathieu-Daudé" <f4bug@amsat.org>
Subject: [PATCH v4 09/25] linux-user/hppa: Document non-use of setup_sigtramp
Date: Mon, 27 Sep 2021 22:00:23 -0400	[thread overview]
Message-ID: <20210928020039.184412-10-richard.henderson@linaro.org> (raw)
In-Reply-To: <20210928020039.184412-1-richard.henderson@linaro.org>

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



  parent reply	other threads:[~2021-09-28  2:15 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-28  2:00 [PATCH v4 00/25] linux-user: Move signal trampolines to new page Richard Henderson
2021-09-28  2:00 ` [PATCH v4 01/25] linux-user: Add infrastructure for a signal trampoline page Richard Henderson
2021-09-28  2:00 ` [PATCH v4 02/25] linux-user/aarch64: Implement setup_sigtramp Richard Henderson
2021-09-28  2:00 ` [PATCH v4 03/25] linux-user/arm: Drop v1 signal frames Richard Henderson
2021-09-28  2:00 ` [PATCH v4 04/25] linux-user/arm: Drop "_v2" from symbols in signal.c Richard Henderson
2021-09-28  2:00 ` [PATCH v4 05/25] linux-user/arm: Implement setup_sigtramp Richard Henderson
2021-09-28  9:31   ` Peter Maydell
2021-09-28 12:28     ` Richard Henderson
2021-09-28  2:00 ` [PATCH v4 06/25] linux-user/alpha: " Richard Henderson
2021-09-28  2:00 ` [PATCH v4 07/25] linux-user/cris: " Richard Henderson
2021-09-28  2:00 ` [PATCH v4 08/25] linux-user/hexagon: " Richard Henderson
2021-09-28  2:00 ` Richard Henderson [this message]
2021-09-28  2:00 ` [PATCH v4 10/25] linux-user/i386: " Richard Henderson
2021-09-28  6:51   ` Philippe Mathieu-Daudé
2021-09-28  2:00 ` [PATCH v4 11/25] linux-user/x86_64: Raise SIGSEGV if SA_RESTORER not set Richard Henderson
2021-09-28  2:00 ` [PATCH v4 12/25] linux-user/m68k: Implement setup_sigtramp Richard Henderson
2021-09-28  2:00 ` [PATCH v4 13/25] linux-user/microblaze: " Richard Henderson
2021-09-28  2:00 ` [PATCH v4 14/25] linux-user/mips: Tidy install_sigtramp Richard Henderson
2021-09-28  2:00 ` [PATCH v4 15/25] linux-user/mips: Implement setup_sigtramp Richard Henderson
2021-09-28  2:00 ` [PATCH v4 16/25] linux-user/nios2: Document non-use of setup_sigtramp Richard Henderson
2021-09-28  9:24   ` Peter Maydell
2021-09-28  2:00 ` [PATCH v4 17/25] linux-user/openrisc: Implement setup_sigtramp Richard Henderson
2021-09-28  2:00 ` [PATCH v4 18/25] linux-user/ppc: Simplify encode_trampoline Richard Henderson
2021-09-28  2:00 ` [PATCH v4 19/25] linux-user/ppc: Implement setup_sigtramp Richard Henderson
2021-09-28  2:00 ` [PATCH v4 20/25] linux-user/riscv: " Richard Henderson
2021-09-28  2:00 ` [PATCH v4 21/25] linux-user/s390x: " Richard Henderson
2021-09-28  2:00 ` [PATCH v4 22/25] linux-user/sh4: " Richard Henderson
2021-09-28  2:00 ` [PATCH v4 23/25] linux-user/sparc: " Richard Henderson
2021-09-28  6:54   ` Philippe Mathieu-Daudé
2021-09-29  7:17   ` Mark Cave-Ayland
2021-09-28  2:00 ` [PATCH v4 24/25] linux-user/xtensa: " Richard Henderson
2021-09-28  2:00 ` [PATCH v4 25/25] linux-user: Remove default for TARGET_ARCH_HAS_SIGTRAMP_PAGE Richard Henderson

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