[PATCH v6 16/17] bsd-user: Implement set_mcontext and get_ucontext_sigreturn for RISCV

[Ajeet Singh]

From: Mark Corbin <mark@dibsco.co.uk>

Added implementations for 'set_mcontext' and 'get_ucontext_sigreturn'
functions for RISC-V architecture,
Both functions ensure that the CPU state and user context are properly
managed.

Signed-off-by: Mark Corbin <mark@dibsco.co.uk>
Signed-off-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Ajeet Singh <itachis@FreeBSD.org>
Co-authored-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 bsd-user/riscv/signal.c | 54 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/bsd-user/riscv/signal.c b/bsd-user/riscv/signal.c
index 072ad821d2..10c940cd49 100644
--- a/bsd-user/riscv/signal.c
+++ b/bsd-user/riscv/signal.c
@@ -114,3 +114,57 @@ abi_long get_mcontext(CPURISCVState *regs, 
target_mcontext_t *mcp,
 
     return 0;
 }
+
+/* Compare with set_mcontext() in riscv/riscv/exec_machdep.c */
+abi_long set_mcontext(CPURISCVState *regs, target_mcontext_t *mcp,
+        int srflag)
+{
+
+    regs->gpr[5] = tswap64(mcp->mc_gpregs.gp_t[0]);
+    regs->gpr[6] = tswap64(mcp->mc_gpregs.gp_t[1]);
+    regs->gpr[7] = tswap64(mcp->mc_gpregs.gp_t[2]);
+    regs->gpr[28] = tswap64(mcp->mc_gpregs.gp_t[3]);
+    regs->gpr[29] = tswap64(mcp->mc_gpregs.gp_t[4]);
+    regs->gpr[30] = tswap64(mcp->mc_gpregs.gp_t[5]);
+    regs->gpr[31] = tswap64(mcp->mc_gpregs.gp_t[6]);
+
+    regs->gpr[8] = tswap64(mcp->mc_gpregs.gp_s[0]);
+    regs->gpr[9] = tswap64(mcp->mc_gpregs.gp_s[1]);
+    regs->gpr[18] = tswap64(mcp->mc_gpregs.gp_s[2]);
+    regs->gpr[19] = tswap64(mcp->mc_gpregs.gp_s[3]);
+    regs->gpr[20] = tswap64(mcp->mc_gpregs.gp_s[4]);
+    regs->gpr[21] = tswap64(mcp->mc_gpregs.gp_s[5]);
+    regs->gpr[22] = tswap64(mcp->mc_gpregs.gp_s[6]);
+    regs->gpr[23] = tswap64(mcp->mc_gpregs.gp_s[7]);
+    regs->gpr[24] = tswap64(mcp->mc_gpregs.gp_s[8]);
+    regs->gpr[25] = tswap64(mcp->mc_gpregs.gp_s[9]);
+    regs->gpr[26] = tswap64(mcp->mc_gpregs.gp_s[10]);
+    regs->gpr[27] = tswap64(mcp->mc_gpregs.gp_s[11]);
+
+    regs->gpr[10] = tswap64(mcp->mc_gpregs.gp_a[0]);
+    regs->gpr[11] = tswap64(mcp->mc_gpregs.gp_a[1]);
+    regs->gpr[12] = tswap64(mcp->mc_gpregs.gp_a[2]);
+    regs->gpr[13] = tswap64(mcp->mc_gpregs.gp_a[3]);
+    regs->gpr[14] = tswap64(mcp->mc_gpregs.gp_a[4]);
+    regs->gpr[15] = tswap64(mcp->mc_gpregs.gp_a[5]);
+    regs->gpr[16] = tswap64(mcp->mc_gpregs.gp_a[6]);
+    regs->gpr[17] = tswap64(mcp->mc_gpregs.gp_a[7]);
+
+
+    regs->gpr[1] = tswap64(mcp->mc_gpregs.gp_ra);
+    regs->gpr[2] = tswap64(mcp->mc_gpregs.gp_sp);
+    regs->gpr[3] = tswap64(mcp->mc_gpregs.gp_gp);
+    regs->gpr[4] = tswap64(mcp->mc_gpregs.gp_tp);
+    regs->pc = tswap64(mcp->mc_gpregs.gp_sepc);
+
+    return 0;
+}
+
+/* Compare with sys_sigreturn() in riscv/riscv/machdep.c */
+abi_long get_ucontext_sigreturn(CPURISCVState *regs,
+                        abi_ulong target_sf, abi_ulong *target_uc)
+{
+
+    *target_uc = target_sf;
+    return 0;
+}
-- 
2.34.1