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

Message ID 20180423075215.4572-4-christophe.lyon@st.com
State New
Headers show
Series
  • FDPIC ABI for ARM
Related show

Commit Message

Christophe Lyon April 23, 2018, 7:51 a.m.
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 <mickael.guene@st.com>
Signed-off-by: Christophe Lyon <christophe.lyon@st.com>


-- 
2.6.3

Comments

Peter Maydell April 23, 2018, 12:49 p.m. | #1
On 23 April 2018 at 08:51, Christophe Lyon <christophe.lyon@st.com> wrote:
> 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 <mickael.guene@st.com>

> Signed-off-by: Christophe Lyon <christophe.lyon@st.com>

>

> 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


"zero"

> +             * r9 points to the main program PT_DYNAMIC info.  */


Something odd seems to have happened to the indentation here.

Nit: */ should be on a line of its own.

> +            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;


Looking at the TaskState struct it already has a pointer
to the image_info struct. So we could just have something like
    bool task_is_fdpic(TaskState *ts)
    {
        return ts->info->personality == PER_LINUX_FDPIC;
    }

and save the need to set up and test a separate flag, I think.

Otherwise looks good.

thanks
-- PMM
Christophe Lyon April 23, 2018, 2:13 p.m. | #2
On 23/04/2018 14:49, Peter Maydell wrote:
> On 23 April 2018 at 08:51, Christophe Lyon <christophe.lyon@st.com> wrote:

>> 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 <mickael.guene@st.com>

>> Signed-off-by: Christophe Lyon <christophe.lyon@st.com>

>>

>> 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

> 

> "zero"

> 

>> +             * r9 points to the main program PT_DYNAMIC info.  */

> 

> Something odd seems to have happened to the indentation here.

> 

> Nit: */ should be on a line of its own.

> 

>> +            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;

> 

> Looking at the TaskState struct it already has a pointer

> to the image_info struct. So we could just have something like

>      bool task_is_fdpic(TaskState *ts)

>      {

>          return ts->info->personality == PER_LINUX_FDPIC;

>      }

> 

> and save the need to set up and test a separate flag, I think.

> 


This patch defines and uses info_is_fdpic, the next one in the
series uses information for TaskState, so I suppose it's OK
not to add this new flag as you suggest, and in the next patch
use info_is_fdpic(ts->info) instead of adding task_is_fdpic() ?

Thanks,

Christophe

> Otherwise looks good.

> 

> thanks

> -- PMM

> .

>
Peter Maydell April 23, 2018, 3:13 p.m. | #3
On 23 April 2018 at 15:13, Christophe Lyon <christophe.lyon@st.com> wrote:
> On 23/04/2018 14:49, Peter Maydell wrote:

> This patch defines and uses info_is_fdpic, the next one in the

> series uses information for TaskState, so I suppose it's OK

> not to add this new flag as you suggest, and in the next patch

> use info_is_fdpic(ts->info) instead of adding task_is_fdpic() ?


Yes, that works too.

thanks
-- PMM

Patch

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);