[v5,15/17] bsd-user: Implement 'get_mcontext' for RISC-V

Commit Message

Ajeet Singh Sept. 7, 2024, 3:19 a.m. UTC

From: Mark Corbin <[e-mail]>

Added the 'get_mcontext' function to extract and populate
the RISC-V machine context from the CPU state.
This function is used to gather the current state of the
general-purpose registers and store it in a 'target_mcontext_'
structure.

Signed-off-by: Mark Corbin <[e-mail]>
Signed-off-by: Ajeet Singh <[e-mail]>
Signed-off-by: Warner Losh <[e-mail]>
Co-authored-by: Warner Losh <[e-mail]>
Reviewed-by: Richard Henderson <[e-mail]>
---
 bsd-user/riscv/signal.c | 53 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

Patch

diff --git a/bsd-user/riscv/signal.c b/bsd-user/riscv/signal.c
index 2597fec2fd..072ad821d2 100644
--- a/bsd-user/riscv/signal.c
+++ b/bsd-user/riscv/signal.c
@@ -61,3 +61,56 @@  abi_long setup_sigframe_arch(CPURISCVState *env, abi_ulong frame_addr,
     get_mcontext(env, mcp, flags);
     return 0;
 }
+
+/*
+ * Compare with get_mcontext() in riscv/riscv/machdep.c
+ * Assumes that the memory is locked if mcp points to user memory.
+ */
+abi_long get_mcontext(CPURISCVState *regs, target_mcontext_t *mcp,
+        int flags)
+{
+
+    mcp->mc_gpregs.gp_t[0] = tswap64(regs->gpr[5]);
+    mcp->mc_gpregs.gp_t[1] = tswap64(regs->gpr[6]);
+    mcp->mc_gpregs.gp_t[2] = tswap64(regs->gpr[7]);
+    mcp->mc_gpregs.gp_t[3] = tswap64(regs->gpr[28]);
+    mcp->mc_gpregs.gp_t[4] = tswap64(regs->gpr[29]);
+    mcp->mc_gpregs.gp_t[5] = tswap64(regs->gpr[30]);
+    mcp->mc_gpregs.gp_t[6] = tswap64(regs->gpr[31]);
+
+    mcp->mc_gpregs.gp_s[0] = tswap64(regs->gpr[8]);
+    mcp->mc_gpregs.gp_s[1] = tswap64(regs->gpr[9]);
+    mcp->mc_gpregs.gp_s[2] = tswap64(regs->gpr[18]);
+    mcp->mc_gpregs.gp_s[3] = tswap64(regs->gpr[19]);
+    mcp->mc_gpregs.gp_s[4] = tswap64(regs->gpr[20]);
+    mcp->mc_gpregs.gp_s[5] = tswap64(regs->gpr[21]);
+    mcp->mc_gpregs.gp_s[6] = tswap64(regs->gpr[22]);
+    mcp->mc_gpregs.gp_s[7] = tswap64(regs->gpr[23]);
+    mcp->mc_gpregs.gp_s[8] = tswap64(regs->gpr[24]);
+    mcp->mc_gpregs.gp_s[9] = tswap64(regs->gpr[25]);
+    mcp->mc_gpregs.gp_s[10] = tswap64(regs->gpr[26]);
+    mcp->mc_gpregs.gp_s[11] = tswap64(regs->gpr[27]);
+
+    mcp->mc_gpregs.gp_a[0] = tswap64(regs->gpr[10]);
+    mcp->mc_gpregs.gp_a[1] = tswap64(regs->gpr[11]);
+    mcp->mc_gpregs.gp_a[2] = tswap64(regs->gpr[12]);
+    mcp->mc_gpregs.gp_a[3] = tswap64(regs->gpr[13]);
+    mcp->mc_gpregs.gp_a[4] = tswap64(regs->gpr[14]);
+    mcp->mc_gpregs.gp_a[5] = tswap64(regs->gpr[15]);
+    mcp->mc_gpregs.gp_a[6] = tswap64(regs->gpr[16]);
+    mcp->mc_gpregs.gp_a[7] = tswap64(regs->gpr[17]);
+
+    if (flags & TARGET_MC_GET_CLEAR_RET) {
+        mcp->mc_gpregs.gp_a[0] = 0; /* a0 */
+        mcp->mc_gpregs.gp_a[1] = 0; /* a1 */
+        mcp->mc_gpregs.gp_t[0] = 0; /* clear syscall error */
+    }
+
+    mcp->mc_gpregs.gp_ra = tswap64(regs->gpr[1]);
+    mcp->mc_gpregs.gp_sp = tswap64(regs->gpr[2]);
+    mcp->mc_gpregs.gp_gp = tswap64(regs->gpr[3]);
+    mcp->mc_gpregs.gp_tp = tswap64(regs->gpr[4]);
+    mcp->mc_gpregs.gp_sepc = tswap64(regs->pc);
+
+    return 0;
+}