target/ppc: Implement ppc_cpu_record_sigsegv

Record DAR, DSISR, and exception_index.  That last means
that we must exit to cpu_loop ourselves, instead of letting
exception_index being overwritten.

This is exactly what the user-mode ppc_cpu_tlb_fill does,
so simply rename it as ppc_cpu_record_sigsegv.

Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

4 files changed, 24 insertions, 9 deletions

diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index 0472ec9154..e946da5f3a 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -1302,9 +1302,6 @@ extern const VMStateDescription vmstate_ppc_cpu;
 
 /*****************************************************************************/
 void ppc_translate_init(void);
-bool ppc_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
-                      MMUAccessType access_type, int mmu_idx,
-                      bool probe, uintptr_t retaddr);
 
 #if !defined(CONFIG_USER_ONLY)
 void ppc_store_sdr1(CPUPPCState *env, target_ulong value);
diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
index 65545ba9ca..1c7a7b4b38 100644
--- a/target/ppc/cpu_init.c
+++ b/target/ppc/cpu_init.c
@@ -9014,9 +9014,11 @@ static const struct SysemuCPUOps ppc_sysemu_ops = {
 
 static const struct TCGCPUOps ppc_tcg_ops = {
   .initialize = ppc_translate_init,
-  .tlb_fill = ppc_cpu_tlb_fill,
 
-#ifndef CONFIG_USER_ONLY
+#ifdef CONFIG_USER_ONLY
+  .record_sigsegv = ppc_cpu_record_sigsegv,
+#else
+  .tlb_fill = ppc_cpu_tlb_fill,
   .cpu_exec_interrupt = ppc_cpu_exec_interrupt,
   .do_interrupt = ppc_cpu_do_interrupt,
   .cpu_exec_enter = ppc_cpu_exec_enter,
diff --git a/target/ppc/internal.h b/target/ppc/internal.h
index 55284369f5..339974b7d8 100644
--- a/target/ppc/internal.h
+++ b/target/ppc/internal.h
@@ -283,5 +283,14 @@ static inline void pte_invalidate(target_ulong *pte0)
 #define PTE_PTEM_MASK 0x7FFFFFBF
 #define PTE_CHECK_MASK (TARGET_PAGE_MASK | 0x7B)
 
+#ifdef CONFIG_USER_ONLY
+void ppc_cpu_record_sigsegv(CPUState *cs, vaddr addr,
+                            MMUAccessType access_type,
+                            bool maperr, uintptr_t ra);
+#else
+bool ppc_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
+                      MMUAccessType access_type, int mmu_idx,
+                      bool probe, uintptr_t retaddr);
+#endif
 
 #endif /* PPC_INTERNAL_H */
diff --git a/target/ppc/user_only_helper.c b/target/ppc/user_only_helper.c
index aa3f867596..7ff76f7a06 100644
--- a/target/ppc/user_only_helper.c
+++ b/target/ppc/user_only_helper.c
@@ -21,16 +21,23 @@
 #include "qemu/osdep.h"
 #include "cpu.h"
 #include "exec/exec-all.h"
+#include "internal.h"
 
-
-bool ppc_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
-                      MMUAccessType access_type, int mmu_idx,
-                      bool probe, uintptr_t retaddr)
+void ppc_cpu_record_sigsegv(CPUState *cs, vaddr address,
+                            MMUAccessType access_type,
+                            bool maperr, uintptr_t retaddr)
 {
     PowerPCCPU *cpu = POWERPC_CPU(cs);
     CPUPPCState *env = &cpu->env;
     int exception, error_code;
 
+    /*
+     * Both DSISR and the "trap number" (exception vector offset,
+     * looked up from exception_index) are present in the linux-user
+     * signal frame.
+     * FIXME: we don't actually populate the trap number properly.
+     * It would be easiest to fill in an env->trap value now.
+     */
     if (access_type == MMU_INST_FETCH) {
         exception = POWERPC_EXCP_ISI;
         error_code = 0x40000000;