[Qemu-devel] [ARM/FDPIC v2 3/4] linux-user: ARM-FDPIC: Add support of FDPIC for ARM.

[Christophe Lyon]

Add FDPIC info into image_info structure since interpreter info is on
stack and needs to be saved to be accessed later on.

Co-Authored-By:  Mickaël Guêné <address@hidden>
Signed-off-by: Christophe Lyon <address@hidden>

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 76d7718..1ee1e38 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -78,6 +78,11 @@ enum {
  */
 #define personality(pers)       (pers & PER_MASK)
 
+int info_is_fdpic(struct image_info *info)
+{
+    return (info->personality == PER_LINUX_FDPIC);
+}
+
 /* this flag is uneffective under linux too, should be deleted */
 #ifndef MAP_DENYWRITE
 #define MAP_DENYWRITE 0
@@ -287,6 +292,24 @@ static inline void init_thread(struct target_pt_regs *regs,
     /* For uClinux PIC binaries.  */
     /* XXX: Linux does this only on ARM with no MMU (do we care ?) */
     regs->uregs[10] = infop->start_data;
+
+    /* Support ARM FDPIC.  */
+    if (info_is_fdpic(infop)) {
+            /* As described in the ABI document, r7 points to the loadmap info
+             * prepared by the kernel. If an interpreter is needed, r8 points
+             * to the interpreter loadmap and r9 points to the interpreter
+             * PT_DYNAMIC info. If no interpreter is needed, r8 is zer0, and
+             * r9 points to the main program PT_DYNAMIC info.  */
+            regs->uregs[7] = infop->loadmap_addr;
+            if (infop->interpreter_loadmap_addr) {
+                /* Executable is dynamically loaded.  */
+                regs->uregs[8] = infop->interpreter_loadmap_addr;
+                regs->uregs[9] = infop->interpreter_pt_dynamic_addr;
+            } else {
+                regs->uregs[8] = 0;
+                regs->uregs[9] = infop->pt_dynamic_addr;
+            }
+        }
 }
 
 #define ELF_NREG    18
@@ -1745,6 +1768,11 @@ static abi_ulong create_elf_tables(abi_ulong p, int 
argc, int envc,
         if (interp_info) {
             interp_info->other_info = info;
             sp = loader_build_fdpic_loadmap(interp_info, sp);
+            info->interpreter_loadmap_addr = interp_info->loadmap_addr;
+            info->interpreter_pt_dynamic_addr = interp_info->pt_dynamic_addr;
+        } else {
+            info->interpreter_loadmap_addr = 0;
+            info->interpreter_pt_dynamic_addr = 0;
         }
     }
 
diff --git a/linux-user/main.c b/linux-user/main.c
index 2acac36..3579f0e 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -4893,6 +4893,9 @@ int main(int argc, char **argv, char **envp)
             env->cp15.sctlr_el[1] |= SCTLR_B;
         }
 #endif
+
+        /* Are we running an FDPIC binary?  */
+        ((TaskState *)thread_cpu->opaque)->is_fdpic = info_is_fdpic(info);
     }
 #elif defined(TARGET_SPARC)
     {
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index da3b517..a2ed148 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -57,6 +57,8 @@ struct image_info {
         uint16_t        nsegs;
         void           *loadsegs;
         abi_ulong       pt_dynamic_addr;
+        abi_ulong       interpreter_loadmap_addr;
+        abi_ulong       interpreter_pt_dynamic_addr;
         struct image_info *other_info;
 };
 
@@ -145,6 +147,9 @@ typedef struct TaskState {
      */
     int signal_pending;
 
+    /* We need to know if we have an FDPIC binary to adapt signal
+     * syscalls.  */
+    int is_fdpic;
 } __attribute__((aligned(16))) TaskState;
 
 extern char *exec_path;
@@ -182,6 +187,7 @@ abi_ulong loader_build_argptr(int envc, int argc, abi_ulong 
sp,
 int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
              struct target_pt_regs * regs, struct image_info *infop,
              struct linux_binprm *);
+int info_is_fdpic(struct image_info *info);
 
 uint32_t get_elf_eflags(int fd);
 int load_elf_binary(struct linux_binprm *bprm, struct image_info *info);
-- 
2.6.3