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[PATCH for-6.2 3/7] linux-user/arm: Use force_sig() to deliver fpa11 emu
From: |
Peter Maydell |
Subject: |
[PATCH for-6.2 3/7] linux-user/arm: Use force_sig() to deliver fpa11 emulation SIGFPE |
Date: |
Fri, 13 Aug 2021 14:18:05 +0100 |
In the Arm target code, when the fpa11 emulation code tells us we
need to send the guest a SIGFPE, we do this with queue_signal(), but
we are using the wrong si_type, and we aren't setting the _sifields
union members corresponding to either the si_type we are using or the
si_type we should be using.
As the existing comment notes, the kernel code for this calls the old
send_sig() function to deliver the signal. This eventually results
in the kernel's signal handling code fabricating a siginfo_t with a
SI_KERNEL code and a zero pid and uid. For QEMU this means we need
to use QEMU_SI_KILL. We already have a function for that:
force_sig() sets up the whole target_siginfo_t the way we need it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
linux-user/arm/cpu_loop.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/linux-user/arm/cpu_loop.c b/linux-user/arm/cpu_loop.c
index 007752f5b74..44324976196 100644
--- a/linux-user/arm/cpu_loop.c
+++ b/linux-user/arm/cpu_loop.c
@@ -266,16 +266,13 @@ static bool emulate_arm_fpa11(CPUARMState *env, uint32_t
opcode)
ts->fpa.fpsr |= raise & ~enabled;
if (raise & enabled) {
- target_siginfo_t info = { };
-
/*
* The kernel's nwfpe emulator does not pass a real si_code.
- * It merely uses send_sig(SIGFPE, current, 1).
+ * It merely uses send_sig(SIGFPE, current, 1), which results in
+ * __send_signal() filling out SI_KERNEL with pid and uid 0 (under
+ * the "SEND_SIG_PRIV" case). That's what our force_sig() does.
*/
- info.si_signo = TARGET_SIGFPE;
- info.si_code = TARGET_SI_KERNEL;
-
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
+ force_sig(TARGET_SIGFPE);
} else {
env->regs[15] += 4;
}
--
2.20.1
- [PATCH for-6.2 0/7] linux-user: Clean up siginfo_t handling for arm, aarch64, Peter Maydell, 2021/08/13
- [PATCH for-6.2 6/7] linux-user/arm: Use force_sig_fault(), Peter Maydell, 2021/08/13
- [PATCH for-6.2 3/7] linux-user/arm: Use force_sig() to deliver fpa11 emulation SIGFPE,
Peter Maydell <=
- [PATCH for-6.2 7/7] linux-user/aarch64: Use force_sig_fault(), Peter Maydell, 2021/08/13
- [PATCH for-6.2 1/7] linux-user/aarch64: Set siginfo_t addr field for SIGTRAP signals, Peter Maydell, 2021/08/13
- [PATCH for-6.2 2/7] linux-user/arm: Set siginfo_t addr field for SIGTRAP signals, Peter Maydell, 2021/08/13
- [PATCH for-6.2 5/7] linux-user: Provide new force_sig_fault() function, Peter Maydell, 2021/08/13