[PULL 05/15] bsd-user:Add get_mcontext function for ARM AArch64

[Warner Losh <imp@bsdimp.com>]

From: Stacey Son <sson@FreeBSD.org>

function to retrieve machine context,it populates the provided
target_mcontext_t structure with information from the CPUARMState
registers.

Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Ajeet Singh <itachis@FreeBSD.org>
Co-authored-by: Kyle Evans <kevans@FreeBSD.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240707191128.10509-6-itachis@FreeBSD.org>
Signed-off-by: Warner Losh <imp@bsdimp.com>
---
 bsd-user/aarch64/signal.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/bsd-user/aarch64/signal.c b/bsd-user/aarch64/signal.c
index 98861f9ab3b..ab3bf8558ab 100644
--- a/bsd-user/aarch64/signal.c
+++ b/bsd-user/aarch64/signal.c
@@ -51,3 +51,33 @@ abi_long set_sigtramp_args(CPUARMState *regs, int sig,
 
     return 0;
 }
+
+/*
+ * Compare to get_mcontext() in arm64/arm64/machdep.c
+ * Assumes that the memory is locked if mcp points to user memory.
+ */
+abi_long get_mcontext(CPUARMState *regs, target_mcontext_t *mcp, int flags)
+{
+    int err = 0, i;
+    uint64_t *gr = mcp->mc_gpregs.gp_x;
+
+    mcp->mc_gpregs.gp_spsr = pstate_read(regs);
+    if (flags & TARGET_MC_GET_CLEAR_RET) {
+        gr[0] = 0UL;
+        mcp->mc_gpregs.gp_spsr &= ~CPSR_C;
+    } else {
+        gr[0] = tswap64(regs->xregs[0]);
+    }
+
+    for (i = 1; i < 30; i++) {
+        gr[i] = tswap64(regs->xregs[i]);
+    }
+
+    mcp->mc_gpregs.gp_sp = tswap64(regs->xregs[TARGET_REG_SP]);
+    mcp->mc_gpregs.gp_lr = tswap64(regs->xregs[TARGET_REG_LR]);
+    mcp->mc_gpregs.gp_elr = tswap64(regs->pc);
+
+    /* XXX FP? */
+
+    return err;
+}
-- 
2.45.1