[ARM/FDPIC,06/21,ARM] FDPIC: Add support for c++ exceptions

Message ID 20180525080354.13295-7-christophe.lyon@st.com
State New
Headers show
Series
  • FDPIC ARM for ARM
Related show

Commit Message

Christophe Lyon May 25, 2018, 8:03 a.m.
When restoring a function address, we also have to restore the FDPIC
register value (r9).

2018-XX-XX  Christophe Lyon  <christophe.lyon@st.com>
	Mickaël Guêné <mickael.guene@st.com>

	gcc/
	* ginclude/unwind-arm-common.h (unwinder_cache): Add reserved5
	field.

	libgcc/
	* config/arm/linux-atomic.c (__ARM_ARCH__): Define.
	(__kernel_cmpxchg): Add FDPIC support.
	(__kernel_dmb): Likewise.
	(__fdpic_cmpxchg): New function.
	(__fdpic_dmb): New function.
	* config/arm/unwind-arm.h (gnu_Unwind_Find_got): New function.
	(_Unwind_decode_typeinfo_ptr): Add FDPIC support.
	* unwindo-arm-common.inc (UCB_PR_GOT): New.
	(funcdesc_t): New struct.
	(get_eit_entry): Add FDPIC support.
	(unwind_phase2): Likewise.
	(unwind_phase2_forced): Likewise.
	(__gnu_Unwind_RaiseException): Likewise.
	(__gnu_Unwind_Resume): Likewise.
	(__gnu_Unwind_Backtrace): Likewise.
	* unwind-pe.h (read_encoded_value_with_base): Likewise.

	libstdc++/
	* libsupc++/eh_personality.cc (get_ttype_entry): Add FDPIC
	support.

Change-Id: Ic0841eb3d7bfb0b3f6d187cd52a660b8fd394d85

-- 
2.6.3

Comments

Kyrill Tkachov June 8, 2018, 10:15 a.m. | #1
Hi Christophe,

On 25/05/18 09:03, Christophe Lyon wrote:
> When restoring a function address, we also have to restore the FDPIC

> register value (r9).

>

> 2018-XX-XX  Christophe Lyon  <christophe.lyon@st.com>

>         Mickaël Guêné <mickael.guene@st.com>

>

>         gcc/

>         * ginclude/unwind-arm-common.h (unwinder_cache): Add reserved5

>         field.

>

>         libgcc/

>         * config/arm/linux-atomic.c (__ARM_ARCH__): Define.

>         (__kernel_cmpxchg): Add FDPIC support.

>         (__kernel_dmb): Likewise.

>         (__fdpic_cmpxchg): New function.

>         (__fdpic_dmb): New function.

>         * config/arm/unwind-arm.h (gnu_Unwind_Find_got): New function.

>         (_Unwind_decode_typeinfo_ptr): Add FDPIC support.

>         * unwindo-arm-common.inc (UCB_PR_GOT): New.

>         (funcdesc_t): New struct.

>         (get_eit_entry): Add FDPIC support.

>         (unwind_phase2): Likewise.

>         (unwind_phase2_forced): Likewise.

>         (__gnu_Unwind_RaiseException): Likewise.

>         (__gnu_Unwind_Resume): Likewise.

>         (__gnu_Unwind_Backtrace): Likewise.

>         * unwind-pe.h (read_encoded_value_with_base): Likewise.

>

>         libstdc++/

>         * libsupc++/eh_personality.cc (get_ttype_entry): Add FDPIC

>         support.

>

> Change-Id: Ic0841eb3d7bfb0b3f6d187cd52a660b8fd394d85

>

> diff --git a/gcc/ginclude/unwind-arm-common.h b/gcc/ginclude/unwind-arm-common.h

> index 8a1a919..150bd0f 100644

> --- a/gcc/ginclude/unwind-arm-common.h

> +++ b/gcc/ginclude/unwind-arm-common.h

> @@ -91,7 +91,7 @@ extern "C" {

>            _uw reserved2;  /* Personality routine address */

>            _uw reserved3;  /* Saved callsite address */

>            _uw reserved4;  /* Forced unwind stop arg */

> -         _uw reserved5;

> +         _uw reserved5;  /* Personality routine GOT value in FDPIC mode.  */

>          }

>        unwinder_cache;

>        /* Propagation barrier cache (valid after phase 1): */

> diff --git a/libgcc/config/arm/linux-atomic.c b/libgcc/config/arm/linux-atomic.c

> index d334c58..a20ad94 100644

> --- a/libgcc/config/arm/linux-atomic.c

> +++ b/libgcc/config/arm/linux-atomic.c

> @@ -23,13 +23,99 @@ a copy of the GCC Runtime Library Exception along with this program;

>  see the files COPYING3 and COPYING.RUNTIME respectively. If not, see

>  <http://www.gnu.org/licenses/>. */

>

> +#if defined(__ARM_ARCH_2__)

> +# define __ARM_ARCH__ 2

> +#endif

> +

> +#if defined(__ARM_ARCH_3__)

> +# define __ARM_ARCH__ 3

> +#endif

> +

> +#if defined(__ARM_ARCH_3M__) || defined(__ARM_ARCH_4__) \

> +  || defined(__ARM_ARCH_4T__)

> +/* We use __ARM_ARCH__ set to 4 here, but in reality it's any processor with

> +   long multiply instructions.  That includes v3M.  */

> +# define __ARM_ARCH__ 4

> +#endif

> +


Support for __ARM_ARCH_2__, __ARM_ARCH_3__, __ARM_ARCH_3M__ has been removed in GCC 9
so this code is dead.

I notice that in the removal I've missed out an occurrence of these in config/arm/lib1funcs.S.
If you want to remove those occurrences as a separate patch that would be preapproved.

Thanks,
Kyrill

> +#if defined(__ARM_ARCH_5__) || defined(__ARM_ARCH_5T__) \

> +  || defined(__ARM_ARCH_5E__) || defined(__ARM_ARCH_5TE__) \

> +  || defined(__ARM_ARCH_5TEJ__)

> +# define __ARM_ARCH__ 5

> +#endif

> +

> +#if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) \

> +  || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) \

> +  || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) \

> +  || defined(__ARM_ARCH_6M__)

> +# define __ARM_ARCH__ 6

> +#endif

> +

> +#if defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) \

> +  || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) \

> +  || defined(__ARM_ARCH_7EM__)

> +# define __ARM_ARCH__ 7

> +#endif

> +

> +#ifndef __ARM_ARCH__

> +#error Unable to determine architecture.

> +#endif

> +

>  /* Kernel helper for compare-and-exchange.  */

>  typedef int (__kernel_cmpxchg_t) (int oldval, int newval, int *ptr);

> +#if __FDPIC__

> +#define __kernel_cmpxchg __fdpic_cmpxchg

> +#else

>  #define __kernel_cmpxchg (*(__kernel_cmpxchg_t *) 0xffff0fc0)

> +#endif

>

>  /* Kernel helper for memory barrier.  */

>  typedef void (__kernel_dmb_t) (void);

> +#if __FDPIC__

> +#define __kernel_dmb __fdpic_dmb

> +#else

>  #define __kernel_dmb (*(__kernel_dmb_t *) 0xffff0fa0)

> +#endif

> +

> +#if __FDPIC__

> +static int __fdpic_cmpxchg (int oldval, int newval, int *ptr)

> +{

> +#if __ARM_ARCH__ < 6

> +  #error architecture support not yet implemented

> +  /* Use swap instruction (but is it always safe ? (interrupt?))  */

> +#else

> +  int result;

> +

> +  asm volatile ("1: ldrex r3, [%[ptr]]\n\t"

> +               "subs  r3, r3, %[oldval]\n\t"

> +               "itt eq\n\t"

> +               "strexeq r3, %[newval], [%[ptr]]\n\t"

> +               "teqeq r3, #1\n\t"

> +               "it eq\n\t"

> +               "beq 1b\n\t"

> +               "rsbs  %[result], r3, #0\n\t"

> +               : [result] "=r" (result)

> +               : [oldval] "r" (oldval) , [newval] "r" (newval), [ptr] "r" (ptr)

> +               : "r3");

> +    return result;

> +#endif

> +}

> +

> +static void __fdpic_dmb ()

> +{

> +#if __ARM_ARCH__ < 6

> +  /* No op? Perhaps flush write buffer ?  */

> +  return ;

> +#else

> + #if __ARM_ARCH__ >= 7

> +  asm volatile ("dmb\n\t");

> + #elif __ARM_ARCH__ == 6

> +  asm volatile ("mcr p15, 0, r0, c7, c10, 5\n\t");

> + #endif

> +#endif

> +}

> +

> +#endif

>

>  /* Note: we implement byte, short and int versions of atomic operations using

>     the above kernel helpers; see linux-atomic-64bit.c for "long long" (64-bit)

> diff --git a/libgcc/config/arm/unwind-arm.h b/libgcc/config/arm/unwind-arm.h

> index 9f7d3f2..a9598eb 100644

> --- a/libgcc/config/arm/unwind-arm.h

> +++ b/libgcc/config/arm/unwind-arm.h

> @@ -36,6 +36,25 @@

>  #ifdef __cplusplus

>  extern "C" {

>  #endif

> +_Unwind_Ptr __attribute__((weak)) __gnu_Unwind_Find_got (_Unwind_Ptr);

> +

> +static inline _Unwind_Ptr gnu_Unwind_Find_got (_Unwind_Ptr ptr)

> +{

> +    _Unwind_Ptr res;

> +

> +    if (__gnu_Unwind_Find_got)

> +       res =  __gnu_Unwind_Find_got (ptr);

> +    else

> +      {

> +       asm volatile ("mov %[result], r9"

> +                     : [result]"=r" (res)

> +                     :

> +                     :);

> +    }

> +

> +    return res;

> +}

> +

>    /* Decode an R_ARM_TARGET2 relocation.  */

>    static inline _Unwind_Word

>    _Unwind_decode_typeinfo_ptr (_Unwind_Word base __attribute__ ((unused)),

> @@ -48,7 +67,12 @@ extern "C" {

>        if (!tmp)

>          return 0;

>

> -#if (defined(linux) && !defined(__uClinux__)) || defined(__NetBSD__) \

> +#if __FDPIC__

> +      /* For FDPIC, we store the offset of the GOT entry. */

> +      /* So, first get GOT from dynamic linker and then use indirect access.  */

> +      tmp += gnu_Unwind_Find_got (ptr);

> +      tmp = *(_Unwind_Word *) tmp;

> +#elif (defined(linux) && !defined(__uClinux__)) || defined(__NetBSD__) \

>      || defined(__FreeBSD__) || defined(__fuchsia__)

>        /* Pc-relative indirect.  */

>  #define _GLIBCXX_OVERRIDE_TTYPE_ENCODING (DW_EH_PE_pcrel | DW_EH_PE_indirect)

> diff --git a/libgcc/unwind-arm-common.inc b/libgcc/unwind-arm-common.inc

> index 76f8fc3..f5415c1 100644

> --- a/libgcc/unwind-arm-common.inc

> +++ b/libgcc/unwind-arm-common.inc

> @@ -62,6 +62,7 @@ __gnu_Unwind_Find_exidx (_Unwind_Ptr, int *);

>  #define UCB_PR_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved2)

>  #define UCB_SAVED_CALLSITE_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved3)

>  #define UCB_FORCED_STOP_ARG(ucbp) ((ucbp)->unwinder_cache.reserved4)

> +#define UCB_PR_GOT(ucbp) ((ucbp)->unwinder_cache.reserved5)

>

>  /* Unwind descriptors.  */

>

> @@ -85,6 +86,12 @@ typedef struct __EIT_entry

>    _uw content;

>  } __EIT_entry;

>

> +/* Only used in FDPIC case.  */

> +struct funcdesc_t {

> +    unsigned int ptr;

> +    unsigned int got;

> +};

> +

>  /* Assembly helper functions.  */

>

>  /* Restore core register state.  Never returns.  */

> @@ -259,7 +266,23 @@ get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address)

>      {

>        /* One of the predefined standard routines.  */

>        _uw idx = (*(_uw *) ucbp->pr_cache.ehtp >> 24) & 0xf;

> +#if __FDPIC__

> +      {

> +       struct funcdesc_t *funcdesc

> +         = (struct funcdesc_t *) __gnu_unwind_get_pr_addr (idx);

> +       if (funcdesc)

> +         {

> +           UCB_PR_ADDR (ucbp) = funcdesc->ptr;

> +           UCB_PR_GOT (ucbp) = funcdesc->got;

> +         }

> +       else

> +         {

> +           UCB_PR_ADDR (ucbp) = 0;

> +         }

> +      }

> +#else

>        UCB_PR_ADDR (ucbp) = __gnu_unwind_get_pr_addr (idx);

> +#endif

>        if (UCB_PR_ADDR (ucbp) == 0)

>          {

>            /* Failed */

> @@ -269,7 +292,13 @@ get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address)

>    else

>      {

>        /* Execute region offset to PR */

> +#if __FDPIC__

>        UCB_PR_ADDR (ucbp) = selfrel_offset31 (ucbp->pr_cache.ehtp);

> +      UCB_PR_GOT (ucbp)

> +       = (unsigned int) gnu_Unwind_Find_got ((_Unwind_Ptr) UCB_PR_ADDR (ucbp));

> +#else

> +      UCB_PR_ADDR (ucbp) = selfrel_offset31 (ucbp->pr_cache.ehtp);

> +#endif

>      }

>    return _URC_OK;

>  }

> @@ -291,14 +320,29 @@ unwind_phase2 (_Unwind_Control_Block * ucbp, phase2_vrs * vrs)

>        UCB_SAVED_CALLSITE_ADDR (ucbp) = VRS_PC(vrs);

>

>        /* Call the pr to decide what to do.  */

> +#if __FDPIC__

> +      {

> +       volatile struct funcdesc_t funcdesc;

> +       funcdesc.ptr = UCB_PR_ADDR (ucbp);

> +       funcdesc.got = UCB_PR_GOT (ucbp);

> +       pr_result = ((personality_routine) &funcdesc)

> +         (_US_UNWIND_FRAME_STARTING, ucbp, (_Unwind_Context *) vrs);

> +      }

> +#else

>        pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))

>          (_US_UNWIND_FRAME_STARTING, ucbp, (_Unwind_Context *) vrs);

> +#endif

>      }

>    while (pr_result == _URC_CONTINUE_UNWIND);

>

>    if (pr_result != _URC_INSTALL_CONTEXT)

>      abort();

>

> +#if __FDPIC__

> +      /* r9 could have been lost due to PLT jump.  Restore correct value.  */

> +      vrs->core.r[9] = gnu_Unwind_Find_got (VRS_PC (vrs));

> +#endif

> +

>    uw_restore_core_regs (vrs, &vrs->core);

>  }

>

> @@ -346,8 +390,18 @@ unwind_phase2_forced (_Unwind_Control_Block *ucbp, phase2_vrs *entry_vrs,

>            next_vrs = saved_vrs;

>

>            /* Call the pr to decide what to do.  */

> +#if __FDPIC__

> +         {

> +           volatile struct funcdesc_t funcdesc;

> +           funcdesc.ptr = UCB_PR_ADDR (ucbp);

> +           funcdesc.got = UCB_PR_GOT (ucbp);

> +           pr_result = ((personality_routine) &funcdesc)

> +             (action, ucbp, (void *) &next_vrs);

> +         }

> +#else

>            pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))

>              (action, ucbp, (void *) &next_vrs);

> +#endif

>

>            saved_vrs.prev_sp = VRS_SP (&next_vrs);

>          }

> @@ -384,6 +438,11 @@ unwind_phase2_forced (_Unwind_Control_Block *ucbp, phase2_vrs *entry_vrs,

>        return _URC_FAILURE;

>      }

>

> +#if __FDPIC__

> +  /* r9 could have been lost due to PLT jump.  Restore correct value.  */

> +  saved_vrs.core.r[9] = gnu_Unwind_Find_got (VRS_PC (&saved_vrs));

> +#endif

> +

>    uw_restore_core_regs (&saved_vrs, &saved_vrs.core);

>  }

>

> @@ -429,8 +488,18 @@ __gnu_Unwind_RaiseException (_Unwind_Control_Block * ucbp,

>          return _URC_FAILURE;

>

>        /* Call the pr to decide what to do.  */

> +#if __FDPIC__

> +      {

> +       volatile struct funcdesc_t funcdesc;

> +       funcdesc.ptr = UCB_PR_ADDR (ucbp);

> +       funcdesc.got = UCB_PR_GOT (ucbp);

> +       pr_result = ((personality_routine) &funcdesc)

> +         (_US_VIRTUAL_UNWIND_FRAME, ucbp, (void *) &saved_vrs);

> +      }

> +#else

>        pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))

>          (_US_VIRTUAL_UNWIND_FRAME, ucbp, (void *) &saved_vrs);

> +#endif

>      }

>    while (pr_result == _URC_CONTINUE_UNWIND);

>

> @@ -488,13 +557,27 @@ __gnu_Unwind_Resume (_Unwind_Control_Block * ucbp, phase2_vrs * entry_vrs)

>      }

>

>    /* Call the cached PR.  */

> +#if __FDPIC__

> +  {

> +    volatile struct funcdesc_t funcdesc;

> +    funcdesc.ptr = UCB_PR_ADDR (ucbp);

> +    funcdesc.got = UCB_PR_GOT (ucbp);

> +    pr_result = ((personality_routine) &funcdesc)

> +      (_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs);

> +  }

> +#else

>    pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))

>          (_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs);

> +#endif

>

>    switch (pr_result)

>      {

>      case _URC_INSTALL_CONTEXT:

>        /* Upload the registers to enter the landing pad.  */

> +#if __FDPIC__

> +      /* r9 could have been lost due to PLT jump.  Restore correct value.  */

> +      entry_vrs->core.r[9] = gnu_Unwind_Find_got (VRS_PC (entry_vrs));

> +#endif

>        uw_restore_core_regs (entry_vrs, &entry_vrs->core);

>

>      case _URC_CONTINUE_UNWIND:

> @@ -586,9 +669,20 @@ __gnu_Unwind_Backtrace(_Unwind_Trace_Fn trace, void * trace_argument,

>          }

>

>        /* Call the pr to decide what to do.  */

> +#if __FDPIC__

> +      {

> +       volatile struct funcdesc_t funcdesc;

> +       funcdesc.ptr = UCB_PR_ADDR (ucbp);

> +       funcdesc.got = UCB_PR_GOT (ucbp);

> +       code = ((personality_routine) &funcdesc)

> +         (_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND,

> +          ucbp, (void *) &saved_vrs);

> +      }

> +#else

>        code = ((personality_routine) UCB_PR_ADDR (ucbp))

>          (_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND,

>           ucbp, (void *) &saved_vrs);

> +#endif

>      }

>    while (code != _URC_END_OF_STACK

>           && code != _URC_FAILURE);

> diff --git a/libgcc/unwind-pe.h b/libgcc/unwind-pe.h

> index dd5ae95..c18dffe 100644

> --- a/libgcc/unwind-pe.h

> +++ b/libgcc/unwind-pe.h

> @@ -259,10 +259,25 @@ read_encoded_value_with_base (unsigned char encoding, _Unwind_Ptr base,

>

>        if (result != 0)

>          {

> +#if __FDPIC__

> +    if ((encoding & DW_EH_PE_pcrel) && (encoding & DW_EH_PE_indirect))

> +      {

> +       result += gnu_Unwind_Find_got ((_Unwind_Ptr) u);

> +       result = *(_Unwind_Internal_Ptr *) result;

> +      }

> +    else

> +      {

> +       result += ((encoding & 0x70) == DW_EH_PE_pcrel

> +                  ? (_Unwind_Internal_Ptr) u : base);

> +       if (encoding & DW_EH_PE_indirect)

> +         result = *(_Unwind_Internal_Ptr *) result;

> +      }

> +#else

>            result += ((encoding & 0x70) == DW_EH_PE_pcrel

>                       ? (_Unwind_Internal_Ptr) u : base);

>            if (encoding & DW_EH_PE_indirect)

>              result = *(_Unwind_Internal_Ptr *) result;

> +#endif

>          }

>      }

>

> diff --git a/libstdc++-v3/libsupc++/eh_personality.cc b/libstdc++-v3/libsupc++/eh_personality.cc

> index 1b336c7..138b606 100644

> --- a/libstdc++-v3/libsupc++/eh_personality.cc

> +++ b/libstdc++-v3/libsupc++/eh_personality.cc

> @@ -93,7 +93,13 @@ get_ttype_entry (lsda_header_info *info, _uleb128_t i)

>    _Unwind_Ptr ptr;

>

>    i *= size_of_encoded_value (info->ttype_encoding);

> -  read_encoded_value_with_base (info->ttype_encoding, info->ttype_base,

> +  read_encoded_value_with_base (

> +#if __FDPIC__

> +               (DW_EH_PE_pcrel | DW_EH_PE_indirect),

> +#else

> +               info->ttype_encoding,

> +#endif

> +               info->ttype_base,

>                                  info->TType - i, &ptr);

>

>    return reinterpret_cast<const std::type_info *>(ptr);

> -- 

> 2.6.3

>
Richard Earnshaw (lists) June 8, 2018, 10:51 a.m. | #2
On 08/06/18 11:15, Kyrill Tkachov wrote:
> Hi Christophe,

> 

> On 25/05/18 09:03, Christophe Lyon wrote:

>> When restoring a function address, we also have to restore the FDPIC

>> register value (r9).

>>

>> 2018-XX-XX  Christophe Lyon  <christophe.lyon@st.com>

>>         Mickaël Guêné <mickael.guene@st.com>

>>

>>         gcc/

>>         * ginclude/unwind-arm-common.h (unwinder_cache): Add reserved5

>>         field.

>>

>>         libgcc/

>>         * config/arm/linux-atomic.c (__ARM_ARCH__): Define.

>>         (__kernel_cmpxchg): Add FDPIC support.

>>         (__kernel_dmb): Likewise.

>>         (__fdpic_cmpxchg): New function.

>>         (__fdpic_dmb): New function.

>>         * config/arm/unwind-arm.h (gnu_Unwind_Find_got): New function.

>>         (_Unwind_decode_typeinfo_ptr): Add FDPIC support.

>>         * unwindo-arm-common.inc (UCB_PR_GOT): New.

>>         (funcdesc_t): New struct.

>>         (get_eit_entry): Add FDPIC support.

>>         (unwind_phase2): Likewise.

>>         (unwind_phase2_forced): Likewise.

>>         (__gnu_Unwind_RaiseException): Likewise.

>>         (__gnu_Unwind_Resume): Likewise.

>>         (__gnu_Unwind_Backtrace): Likewise.

>>         * unwind-pe.h (read_encoded_value_with_base): Likewise.

>>

>>         libstdc++/

>>         * libsupc++/eh_personality.cc (get_ttype_entry): Add FDPIC

>>         support.

>>

>> Change-Id: Ic0841eb3d7bfb0b3f6d187cd52a660b8fd394d85

>>

>> diff --git a/gcc/ginclude/unwind-arm-common.h

>> b/gcc/ginclude/unwind-arm-common.h

>> index 8a1a919..150bd0f 100644

>> --- a/gcc/ginclude/unwind-arm-common.h

>> +++ b/gcc/ginclude/unwind-arm-common.h

>> @@ -91,7 +91,7 @@ extern "C" {

>>            _uw reserved2;  /* Personality routine address */

>>            _uw reserved3;  /* Saved callsite address */

>>            _uw reserved4;  /* Forced unwind stop arg */

>> -         _uw reserved5;

>> +         _uw reserved5;  /* Personality routine GOT value in FDPIC

>> mode.  */

>>          }

>>        unwinder_cache;

>>        /* Propagation barrier cache (valid after phase 1): */

>> diff --git a/libgcc/config/arm/linux-atomic.c

>> b/libgcc/config/arm/linux-atomic.c

>> index d334c58..a20ad94 100644

>> --- a/libgcc/config/arm/linux-atomic.c

>> +++ b/libgcc/config/arm/linux-atomic.c

>> @@ -23,13 +23,99 @@ a copy of the GCC Runtime Library Exception along

>> with this program;

>>  see the files COPYING3 and COPYING.RUNTIME respectively. If not, see

>>  <http://www.gnu.org/licenses/>. */

>>

>> +#if defined(__ARM_ARCH_2__)

>> +# define __ARM_ARCH__ 2

>> +#endif

>> +

>> +#if defined(__ARM_ARCH_3__)

>> +# define __ARM_ARCH__ 3

>> +#endif

>> +

>> +#if defined(__ARM_ARCH_3M__) || defined(__ARM_ARCH_4__) \

>> +  || defined(__ARM_ARCH_4T__)

>> +/* We use __ARM_ARCH__ set to 4 here, but in reality it's any

>> processor with

>> +   long multiply instructions.  That includes v3M.  */

>> +# define __ARM_ARCH__ 4

>> +#endif

>> +

> 

> Support for __ARM_ARCH_2__, __ARM_ARCH_3__, __ARM_ARCH_3M__ has been

> removed in GCC 9

> so this code is dead.


Better still, use the ACLE pre-defines rather than the awkward GCC
versions which need updating each time a new architecture variant is added.

R.

> 

> I notice that in the removal I've missed out an occurrence of these in

> config/arm/lib1funcs.S.

> If you want to remove those occurrences as a separate patch that would

> be preapproved.

> 

> Thanks,

> Kyrill

> 

>> +#if defined(__ARM_ARCH_5__) || defined(__ARM_ARCH_5T__) \

>> +  || defined(__ARM_ARCH_5E__) || defined(__ARM_ARCH_5TE__) \

>> +  || defined(__ARM_ARCH_5TEJ__)

>> +# define __ARM_ARCH__ 5

>> +#endif

>> +

>> +#if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) \

>> +  || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) \

>> +  || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) \

>> +  || defined(__ARM_ARCH_6M__)

>> +# define __ARM_ARCH__ 6

>> +#endif

>> +

>> +#if defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) \

>> +  || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) \

>> +  || defined(__ARM_ARCH_7EM__)

>> +# define __ARM_ARCH__ 7

>> +#endif

>> +

>> +#ifndef __ARM_ARCH__

>> +#error Unable to determine architecture.

>> +#endif

>> +

>>  /* Kernel helper for compare-and-exchange.  */

>>  typedef int (__kernel_cmpxchg_t) (int oldval, int newval, int *ptr);

>> +#if __FDPIC__

>> +#define __kernel_cmpxchg __fdpic_cmpxchg

>> +#else

>>  #define __kernel_cmpxchg (*(__kernel_cmpxchg_t *) 0xffff0fc0)

>> +#endif

>>

>>  /* Kernel helper for memory barrier.  */

>>  typedef void (__kernel_dmb_t) (void);

>> +#if __FDPIC__

>> +#define __kernel_dmb __fdpic_dmb

>> +#else

>>  #define __kernel_dmb (*(__kernel_dmb_t *) 0xffff0fa0)

>> +#endif

>> +

>> +#if __FDPIC__

>> +static int __fdpic_cmpxchg (int oldval, int newval, int *ptr)

>> +{

>> +#if __ARM_ARCH__ < 6

>> +  #error architecture support not yet implemented

>> +  /* Use swap instruction (but is it always safe ? (interrupt?))  */

>> +#else

>> +  int result;

>> +

>> +  asm volatile ("1: ldrex r3, [%[ptr]]\n\t"

>> +               "subs  r3, r3, %[oldval]\n\t"

>> +               "itt eq\n\t"

>> +               "strexeq r3, %[newval], [%[ptr]]\n\t"

>> +               "teqeq r3, #1\n\t"

>> +               "it eq\n\t"

>> +               "beq 1b\n\t"

>> +               "rsbs  %[result], r3, #0\n\t"

>> +               : [result] "=r" (result)

>> +               : [oldval] "r" (oldval) , [newval] "r" (newval), [ptr]

>> "r" (ptr)

>> +               : "r3");

>> +    return result;

>> +#endif

>> +}

>> +

>> +static void __fdpic_dmb ()

>> +{

>> +#if __ARM_ARCH__ < 6

>> +  /* No op? Perhaps flush write buffer ?  */

>> +  return ;

>> +#else

>> + #if __ARM_ARCH__ >= 7

>> +  asm volatile ("dmb\n\t");

>> + #elif __ARM_ARCH__ == 6

>> +  asm volatile ("mcr p15, 0, r0, c7, c10, 5\n\t");

>> + #endif

>> +#endif

>> +}

>> +

>> +#endif

>>

>>  /* Note: we implement byte, short and int versions of atomic

>> operations using

>>     the above kernel helpers; see linux-atomic-64bit.c for "long long"

>> (64-bit)

>> diff --git a/libgcc/config/arm/unwind-arm.h

>> b/libgcc/config/arm/unwind-arm.h

>> index 9f7d3f2..a9598eb 100644

>> --- a/libgcc/config/arm/unwind-arm.h

>> +++ b/libgcc/config/arm/unwind-arm.h

>> @@ -36,6 +36,25 @@

>>  #ifdef __cplusplus

>>  extern "C" {

>>  #endif

>> +_Unwind_Ptr __attribute__((weak)) __gnu_Unwind_Find_got (_Unwind_Ptr);

>> +

>> +static inline _Unwind_Ptr gnu_Unwind_Find_got (_Unwind_Ptr ptr)

>> +{

>> +    _Unwind_Ptr res;

>> +

>> +    if (__gnu_Unwind_Find_got)

>> +       res =  __gnu_Unwind_Find_got (ptr);

>> +    else

>> +      {

>> +       asm volatile ("mov %[result], r9"

>> +                     : [result]"=r" (res)

>> +                     :

>> +                     :);

>> +    }

>> +

>> +    return res;

>> +}

>> +

>>    /* Decode an R_ARM_TARGET2 relocation.  */

>>    static inline _Unwind_Word

>>    _Unwind_decode_typeinfo_ptr (_Unwind_Word base __attribute__

>> ((unused)),

>> @@ -48,7 +67,12 @@ extern "C" {

>>        if (!tmp)

>>          return 0;

>>

>> -#if (defined(linux) && !defined(__uClinux__)) || defined(__NetBSD__) \

>> +#if __FDPIC__

>> +      /* For FDPIC, we store the offset of the GOT entry. */

>> +      /* So, first get GOT from dynamic linker and then use indirect

>> access.  */

>> +      tmp += gnu_Unwind_Find_got (ptr);

>> +      tmp = *(_Unwind_Word *) tmp;

>> +#elif (defined(linux) && !defined(__uClinux__)) || defined(__NetBSD__) \

>>      || defined(__FreeBSD__) || defined(__fuchsia__)

>>        /* Pc-relative indirect.  */

>>  #define _GLIBCXX_OVERRIDE_TTYPE_ENCODING (DW_EH_PE_pcrel |

>> DW_EH_PE_indirect)

>> diff --git a/libgcc/unwind-arm-common.inc b/libgcc/unwind-arm-common.inc

>> index 76f8fc3..f5415c1 100644

>> --- a/libgcc/unwind-arm-common.inc

>> +++ b/libgcc/unwind-arm-common.inc

>> @@ -62,6 +62,7 @@ __gnu_Unwind_Find_exidx (_Unwind_Ptr, int *);

>>  #define UCB_PR_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved2)

>>  #define UCB_SAVED_CALLSITE_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved3)

>>  #define UCB_FORCED_STOP_ARG(ucbp) ((ucbp)->unwinder_cache.reserved4)

>> +#define UCB_PR_GOT(ucbp) ((ucbp)->unwinder_cache.reserved5)

>>

>>  /* Unwind descriptors.  */

>>

>> @@ -85,6 +86,12 @@ typedef struct __EIT_entry

>>    _uw content;

>>  } __EIT_entry;

>>

>> +/* Only used in FDPIC case.  */

>> +struct funcdesc_t {

>> +    unsigned int ptr;

>> +    unsigned int got;

>> +};

>> +

>>  /* Assembly helper functions.  */

>>

>>  /* Restore core register state.  Never returns.  */

>> @@ -259,7 +266,23 @@ get_eit_entry (_Unwind_Control_Block *ucbp, _uw

>> return_address)

>>      {

>>        /* One of the predefined standard routines.  */

>>        _uw idx = (*(_uw *) ucbp->pr_cache.ehtp >> 24) & 0xf;

>> +#if __FDPIC__

>> +      {

>> +       struct funcdesc_t *funcdesc

>> +         = (struct funcdesc_t *) __gnu_unwind_get_pr_addr (idx);

>> +       if (funcdesc)

>> +         {

>> +           UCB_PR_ADDR (ucbp) = funcdesc->ptr;

>> +           UCB_PR_GOT (ucbp) = funcdesc->got;

>> +         }

>> +       else

>> +         {

>> +           UCB_PR_ADDR (ucbp) = 0;

>> +         }

>> +      }

>> +#else

>>        UCB_PR_ADDR (ucbp) = __gnu_unwind_get_pr_addr (idx);

>> +#endif

>>        if (UCB_PR_ADDR (ucbp) == 0)

>>          {

>>            /* Failed */

>> @@ -269,7 +292,13 @@ get_eit_entry (_Unwind_Control_Block *ucbp, _uw

>> return_address)

>>    else

>>      {

>>        /* Execute region offset to PR */

>> +#if __FDPIC__

>>        UCB_PR_ADDR (ucbp) = selfrel_offset31 (ucbp->pr_cache.ehtp);

>> +      UCB_PR_GOT (ucbp)

>> +       = (unsigned int) gnu_Unwind_Find_got ((_Unwind_Ptr)

>> UCB_PR_ADDR (ucbp));

>> +#else

>> +      UCB_PR_ADDR (ucbp) = selfrel_offset31 (ucbp->pr_cache.ehtp);

>> +#endif

>>      }

>>    return _URC_OK;

>>  }

>> @@ -291,14 +320,29 @@ unwind_phase2 (_Unwind_Control_Block * ucbp,

>> phase2_vrs * vrs)

>>        UCB_SAVED_CALLSITE_ADDR (ucbp) = VRS_PC(vrs);

>>

>>        /* Call the pr to decide what to do.  */

>> +#if __FDPIC__

>> +      {

>> +       volatile struct funcdesc_t funcdesc;

>> +       funcdesc.ptr = UCB_PR_ADDR (ucbp);

>> +       funcdesc.got = UCB_PR_GOT (ucbp);

>> +       pr_result = ((personality_routine) &funcdesc)

>> +         (_US_UNWIND_FRAME_STARTING, ucbp, (_Unwind_Context *) vrs);

>> +      }

>> +#else

>>        pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))

>>          (_US_UNWIND_FRAME_STARTING, ucbp, (_Unwind_Context *) vrs);

>> +#endif

>>      }

>>    while (pr_result == _URC_CONTINUE_UNWIND);

>>

>>    if (pr_result != _URC_INSTALL_CONTEXT)

>>      abort();

>>

>> +#if __FDPIC__

>> +      /* r9 could have been lost due to PLT jump.  Restore correct

>> value.  */

>> +      vrs->core.r[9] = gnu_Unwind_Find_got (VRS_PC (vrs));

>> +#endif

>> +

>>    uw_restore_core_regs (vrs, &vrs->core);

>>  }

>>

>> @@ -346,8 +390,18 @@ unwind_phase2_forced (_Unwind_Control_Block

>> *ucbp, phase2_vrs *entry_vrs,

>>            next_vrs = saved_vrs;

>>

>>            /* Call the pr to decide what to do.  */

>> +#if __FDPIC__

>> +         {

>> +           volatile struct funcdesc_t funcdesc;

>> +           funcdesc.ptr = UCB_PR_ADDR (ucbp);

>> +           funcdesc.got = UCB_PR_GOT (ucbp);

>> +           pr_result = ((personality_routine) &funcdesc)

>> +             (action, ucbp, (void *) &next_vrs);

>> +         }

>> +#else

>>            pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))

>>              (action, ucbp, (void *) &next_vrs);

>> +#endif

>>

>>            saved_vrs.prev_sp = VRS_SP (&next_vrs);

>>          }

>> @@ -384,6 +438,11 @@ unwind_phase2_forced (_Unwind_Control_Block

>> *ucbp, phase2_vrs *entry_vrs,

>>        return _URC_FAILURE;

>>      }

>>

>> +#if __FDPIC__

>> +  /* r9 could have been lost due to PLT jump.  Restore correct

>> value.  */

>> +  saved_vrs.core.r[9] = gnu_Unwind_Find_got (VRS_PC (&saved_vrs));

>> +#endif

>> +

>>    uw_restore_core_regs (&saved_vrs, &saved_vrs.core);

>>  }

>>

>> @@ -429,8 +488,18 @@ __gnu_Unwind_RaiseException

>> (_Unwind_Control_Block * ucbp,

>>          return _URC_FAILURE;

>>

>>        /* Call the pr to decide what to do.  */

>> +#if __FDPIC__

>> +      {

>> +       volatile struct funcdesc_t funcdesc;

>> +       funcdesc.ptr = UCB_PR_ADDR (ucbp);

>> +       funcdesc.got = UCB_PR_GOT (ucbp);

>> +       pr_result = ((personality_routine) &funcdesc)

>> +         (_US_VIRTUAL_UNWIND_FRAME, ucbp, (void *) &saved_vrs);

>> +      }

>> +#else

>>        pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))

>>          (_US_VIRTUAL_UNWIND_FRAME, ucbp, (void *) &saved_vrs);

>> +#endif

>>      }

>>    while (pr_result == _URC_CONTINUE_UNWIND);

>>

>> @@ -488,13 +557,27 @@ __gnu_Unwind_Resume (_Unwind_Control_Block *

>> ucbp, phase2_vrs * entry_vrs)

>>      }

>>

>>    /* Call the cached PR.  */

>> +#if __FDPIC__

>> +  {

>> +    volatile struct funcdesc_t funcdesc;

>> +    funcdesc.ptr = UCB_PR_ADDR (ucbp);

>> +    funcdesc.got = UCB_PR_GOT (ucbp);

>> +    pr_result = ((personality_routine) &funcdesc)

>> +      (_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs);

>> +  }

>> +#else

>>    pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))

>>          (_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs);

>> +#endif

>>

>>    switch (pr_result)

>>      {

>>      case _URC_INSTALL_CONTEXT:

>>        /* Upload the registers to enter the landing pad.  */

>> +#if __FDPIC__

>> +      /* r9 could have been lost due to PLT jump.  Restore correct

>> value.  */

>> +      entry_vrs->core.r[9] = gnu_Unwind_Find_got (VRS_PC (entry_vrs));

>> +#endif

>>        uw_restore_core_regs (entry_vrs, &entry_vrs->core);

>>

>>      case _URC_CONTINUE_UNWIND:

>> @@ -586,9 +669,20 @@ __gnu_Unwind_Backtrace(_Unwind_Trace_Fn trace,

>> void * trace_argument,

>>          }

>>

>>        /* Call the pr to decide what to do.  */

>> +#if __FDPIC__

>> +      {

>> +       volatile struct funcdesc_t funcdesc;

>> +       funcdesc.ptr = UCB_PR_ADDR (ucbp);

>> +       funcdesc.got = UCB_PR_GOT (ucbp);

>> +       code = ((personality_routine) &funcdesc)

>> +         (_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND,

>> +          ucbp, (void *) &saved_vrs);

>> +      }

>> +#else

>>        code = ((personality_routine) UCB_PR_ADDR (ucbp))

>>          (_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND,

>>           ucbp, (void *) &saved_vrs);

>> +#endif

>>      }

>>    while (code != _URC_END_OF_STACK

>>           && code != _URC_FAILURE);

>> diff --git a/libgcc/unwind-pe.h b/libgcc/unwind-pe.h

>> index dd5ae95..c18dffe 100644

>> --- a/libgcc/unwind-pe.h

>> +++ b/libgcc/unwind-pe.h

>> @@ -259,10 +259,25 @@ read_encoded_value_with_base (unsigned char

>> encoding, _Unwind_Ptr base,

>>

>>        if (result != 0)

>>          {

>> +#if __FDPIC__

>> +    if ((encoding & DW_EH_PE_pcrel) && (encoding & DW_EH_PE_indirect))

>> +      {

>> +       result += gnu_Unwind_Find_got ((_Unwind_Ptr) u);

>> +       result = *(_Unwind_Internal_Ptr *) result;

>> +      }

>> +    else

>> +      {

>> +       result += ((encoding & 0x70) == DW_EH_PE_pcrel

>> +                  ? (_Unwind_Internal_Ptr) u : base);

>> +       if (encoding & DW_EH_PE_indirect)

>> +         result = *(_Unwind_Internal_Ptr *) result;

>> +      }

>> +#else

>>            result += ((encoding & 0x70) == DW_EH_PE_pcrel

>>                       ? (_Unwind_Internal_Ptr) u : base);

>>            if (encoding & DW_EH_PE_indirect)

>>              result = *(_Unwind_Internal_Ptr *) result;

>> +#endif

>>          }

>>      }

>>

>> diff --git a/libstdc++-v3/libsupc++/eh_personality.cc

>> b/libstdc++-v3/libsupc++/eh_personality.cc

>> index 1b336c7..138b606 100644

>> --- a/libstdc++-v3/libsupc++/eh_personality.cc

>> +++ b/libstdc++-v3/libsupc++/eh_personality.cc

>> @@ -93,7 +93,13 @@ get_ttype_entry (lsda_header_info *info, _uleb128_t i)

>>    _Unwind_Ptr ptr;

>>

>>    i *= size_of_encoded_value (info->ttype_encoding);

>> -  read_encoded_value_with_base (info->ttype_encoding, info->ttype_base,

>> +  read_encoded_value_with_base (

>> +#if __FDPIC__

>> +               (DW_EH_PE_pcrel | DW_EH_PE_indirect),

>> +#else

>> +               info->ttype_encoding,

>> +#endif

>> +               info->ttype_base,

>>                                  info->TType - i, &ptr);

>>

>>    return reinterpret_cast<const std::type_info *>(ptr);

>> -- 

>> 2.6.3

>>

>
Christophe Lyon June 11, 2018, 6:49 a.m. | #3
On 8 June 2018 at 12:51, Richard Earnshaw (lists)
<Richard.Earnshaw@arm.com> wrote:
> On 08/06/18 11:15, Kyrill Tkachov wrote:

>> Hi Christophe,

>>

>> On 25/05/18 09:03, Christophe Lyon wrote:

>>> When restoring a function address, we also have to restore the FDPIC

>>> register value (r9).

>>>

>>> 2018-XX-XX  Christophe Lyon  <christophe.lyon@st.com>

>>>         Mickaël Guêné <mickael.guene@st.com>

>>>

>>>         gcc/

>>>         * ginclude/unwind-arm-common.h (unwinder_cache): Add reserved5

>>>         field.

>>>

>>>         libgcc/

>>>         * config/arm/linux-atomic.c (__ARM_ARCH__): Define.

>>>         (__kernel_cmpxchg): Add FDPIC support.

>>>         (__kernel_dmb): Likewise.

>>>         (__fdpic_cmpxchg): New function.

>>>         (__fdpic_dmb): New function.

>>>         * config/arm/unwind-arm.h (gnu_Unwind_Find_got): New function.

>>>         (_Unwind_decode_typeinfo_ptr): Add FDPIC support.

>>>         * unwindo-arm-common.inc (UCB_PR_GOT): New.

>>>         (funcdesc_t): New struct.

>>>         (get_eit_entry): Add FDPIC support.

>>>         (unwind_phase2): Likewise.

>>>         (unwind_phase2_forced): Likewise.

>>>         (__gnu_Unwind_RaiseException): Likewise.

>>>         (__gnu_Unwind_Resume): Likewise.

>>>         (__gnu_Unwind_Backtrace): Likewise.

>>>         * unwind-pe.h (read_encoded_value_with_base): Likewise.

>>>

>>>         libstdc++/

>>>         * libsupc++/eh_personality.cc (get_ttype_entry): Add FDPIC

>>>         support.

>>>

>>> Change-Id: Ic0841eb3d7bfb0b3f6d187cd52a660b8fd394d85

>>>

>>> diff --git a/gcc/ginclude/unwind-arm-common.h

>>> b/gcc/ginclude/unwind-arm-common.h

>>> index 8a1a919..150bd0f 100644

>>> --- a/gcc/ginclude/unwind-arm-common.h

>>> +++ b/gcc/ginclude/unwind-arm-common.h

>>> @@ -91,7 +91,7 @@ extern "C" {

>>>            _uw reserved2;  /* Personality routine address */

>>>            _uw reserved3;  /* Saved callsite address */

>>>            _uw reserved4;  /* Forced unwind stop arg */

>>> -         _uw reserved5;

>>> +         _uw reserved5;  /* Personality routine GOT value in FDPIC

>>> mode.  */

>>>          }

>>>        unwinder_cache;

>>>        /* Propagation barrier cache (valid after phase 1): */

>>> diff --git a/libgcc/config/arm/linux-atomic.c

>>> b/libgcc/config/arm/linux-atomic.c

>>> index d334c58..a20ad94 100644

>>> --- a/libgcc/config/arm/linux-atomic.c

>>> +++ b/libgcc/config/arm/linux-atomic.c

>>> @@ -23,13 +23,99 @@ a copy of the GCC Runtime Library Exception along

>>> with this program;

>>>  see the files COPYING3 and COPYING.RUNTIME respectively. If not, see

>>>  <http://www.gnu.org/licenses/>. */

>>>

>>> +#if defined(__ARM_ARCH_2__)

>>> +# define __ARM_ARCH__ 2

>>> +#endif

>>> +

>>> +#if defined(__ARM_ARCH_3__)

>>> +# define __ARM_ARCH__ 3

>>> +#endif

>>> +

>>> +#if defined(__ARM_ARCH_3M__) || defined(__ARM_ARCH_4__) \

>>> +  || defined(__ARM_ARCH_4T__)

>>> +/* We use __ARM_ARCH__ set to 4 here, but in reality it's any

>>> processor with

>>> +   long multiply instructions.  That includes v3M.  */

>>> +# define __ARM_ARCH__ 4

>>> +#endif

>>> +

>>

>> Support for __ARM_ARCH_2__, __ARM_ARCH_3__, __ARM_ARCH_3M__ has been

>> removed in GCC 9

>> so this code is dead.

>

> Better still, use the ACLE pre-defines rather than the awkward GCC

> versions which need updating each time a new architecture variant is added.

>


Indeed, that's a better solution. I did notice discrepancies between
several copies of this code block in various GCC libs.


> R.

>

>>

>> I notice that in the removal I've missed out an occurrence of these in

>> config/arm/lib1funcs.S.

>> If you want to remove those occurrences as a separate patch that would

>> be preapproved.

>>

>> Thanks,

>> Kyrill

>>

>>> +#if defined(__ARM_ARCH_5__) || defined(__ARM_ARCH_5T__) \

>>> +  || defined(__ARM_ARCH_5E__) || defined(__ARM_ARCH_5TE__) \

>>> +  || defined(__ARM_ARCH_5TEJ__)

>>> +# define __ARM_ARCH__ 5

>>> +#endif

>>> +

>>> +#if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) \

>>> +  || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) \

>>> +  || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) \

>>> +  || defined(__ARM_ARCH_6M__)

>>> +# define __ARM_ARCH__ 6

>>> +#endif

>>> +

>>> +#if defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) \

>>> +  || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) \

>>> +  || defined(__ARM_ARCH_7EM__)

>>> +# define __ARM_ARCH__ 7

>>> +#endif

>>> +

>>> +#ifndef __ARM_ARCH__

>>> +#error Unable to determine architecture.

>>> +#endif

>>> +

>>>  /* Kernel helper for compare-and-exchange.  */

>>>  typedef int (__kernel_cmpxchg_t) (int oldval, int newval, int *ptr);

>>> +#if __FDPIC__

>>> +#define __kernel_cmpxchg __fdpic_cmpxchg

>>> +#else

>>>  #define __kernel_cmpxchg (*(__kernel_cmpxchg_t *) 0xffff0fc0)

>>> +#endif

>>>

>>>  /* Kernel helper for memory barrier.  */

>>>  typedef void (__kernel_dmb_t) (void);

>>> +#if __FDPIC__

>>> +#define __kernel_dmb __fdpic_dmb

>>> +#else

>>>  #define __kernel_dmb (*(__kernel_dmb_t *) 0xffff0fa0)

>>> +#endif

>>> +

>>> +#if __FDPIC__

>>> +static int __fdpic_cmpxchg (int oldval, int newval, int *ptr)

>>> +{

>>> +#if __ARM_ARCH__ < 6

>>> +  #error architecture support not yet implemented

>>> +  /* Use swap instruction (but is it always safe ? (interrupt?))  */

>>> +#else

>>> +  int result;

>>> +

>>> +  asm volatile ("1: ldrex r3, [%[ptr]]\n\t"

>>> +               "subs  r3, r3, %[oldval]\n\t"

>>> +               "itt eq\n\t"

>>> +               "strexeq r3, %[newval], [%[ptr]]\n\t"

>>> +               "teqeq r3, #1\n\t"

>>> +               "it eq\n\t"

>>> +               "beq 1b\n\t"

>>> +               "rsbs  %[result], r3, #0\n\t"

>>> +               : [result] "=r" (result)

>>> +               : [oldval] "r" (oldval) , [newval] "r" (newval), [ptr]

>>> "r" (ptr)

>>> +               : "r3");

>>> +    return result;

>>> +#endif

>>> +}

>>> +

>>> +static void __fdpic_dmb ()

>>> +{

>>> +#if __ARM_ARCH__ < 6

>>> +  /* No op? Perhaps flush write buffer ?  */

>>> +  return ;

>>> +#else

>>> + #if __ARM_ARCH__ >= 7

>>> +  asm volatile ("dmb\n\t");

>>> + #elif __ARM_ARCH__ == 6

>>> +  asm volatile ("mcr p15, 0, r0, c7, c10, 5\n\t");

>>> + #endif

>>> +#endif

>>> +}

>>> +

>>> +#endif

>>>

>>>  /* Note: we implement byte, short and int versions of atomic

>>> operations using

>>>     the above kernel helpers; see linux-atomic-64bit.c for "long long"

>>> (64-bit)

>>> diff --git a/libgcc/config/arm/unwind-arm.h

>>> b/libgcc/config/arm/unwind-arm.h

>>> index 9f7d3f2..a9598eb 100644

>>> --- a/libgcc/config/arm/unwind-arm.h

>>> +++ b/libgcc/config/arm/unwind-arm.h

>>> @@ -36,6 +36,25 @@

>>>  #ifdef __cplusplus

>>>  extern "C" {

>>>  #endif

>>> +_Unwind_Ptr __attribute__((weak)) __gnu_Unwind_Find_got (_Unwind_Ptr);

>>> +

>>> +static inline _Unwind_Ptr gnu_Unwind_Find_got (_Unwind_Ptr ptr)

>>> +{

>>> +    _Unwind_Ptr res;

>>> +

>>> +    if (__gnu_Unwind_Find_got)

>>> +       res =  __gnu_Unwind_Find_got (ptr);

>>> +    else

>>> +      {

>>> +       asm volatile ("mov %[result], r9"

>>> +                     : [result]"=r" (res)

>>> +                     :

>>> +                     :);

>>> +    }

>>> +

>>> +    return res;

>>> +}

>>> +

>>>    /* Decode an R_ARM_TARGET2 relocation.  */

>>>    static inline _Unwind_Word

>>>    _Unwind_decode_typeinfo_ptr (_Unwind_Word base __attribute__

>>> ((unused)),

>>> @@ -48,7 +67,12 @@ extern "C" {

>>>        if (!tmp)

>>>          return 0;

>>>

>>> -#if (defined(linux) && !defined(__uClinux__)) || defined(__NetBSD__) \

>>> +#if __FDPIC__

>>> +      /* For FDPIC, we store the offset of the GOT entry. */

>>> +      /* So, first get GOT from dynamic linker and then use indirect

>>> access.  */

>>> +      tmp += gnu_Unwind_Find_got (ptr);

>>> +      tmp = *(_Unwind_Word *) tmp;

>>> +#elif (defined(linux) && !defined(__uClinux__)) || defined(__NetBSD__) \

>>>      || defined(__FreeBSD__) || defined(__fuchsia__)

>>>        /* Pc-relative indirect.  */

>>>  #define _GLIBCXX_OVERRIDE_TTYPE_ENCODING (DW_EH_PE_pcrel |

>>> DW_EH_PE_indirect)

>>> diff --git a/libgcc/unwind-arm-common.inc b/libgcc/unwind-arm-common.inc

>>> index 76f8fc3..f5415c1 100644

>>> --- a/libgcc/unwind-arm-common.inc

>>> +++ b/libgcc/unwind-arm-common.inc

>>> @@ -62,6 +62,7 @@ __gnu_Unwind_Find_exidx (_Unwind_Ptr, int *);

>>>  #define UCB_PR_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved2)

>>>  #define UCB_SAVED_CALLSITE_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved3)

>>>  #define UCB_FORCED_STOP_ARG(ucbp) ((ucbp)->unwinder_cache.reserved4)

>>> +#define UCB_PR_GOT(ucbp) ((ucbp)->unwinder_cache.reserved5)

>>>

>>>  /* Unwind descriptors.  */

>>>

>>> @@ -85,6 +86,12 @@ typedef struct __EIT_entry

>>>    _uw content;

>>>  } __EIT_entry;

>>>

>>> +/* Only used in FDPIC case.  */

>>> +struct funcdesc_t {

>>> +    unsigned int ptr;

>>> +    unsigned int got;

>>> +};

>>> +

>>>  /* Assembly helper functions.  */

>>>

>>>  /* Restore core register state.  Never returns.  */

>>> @@ -259,7 +266,23 @@ get_eit_entry (_Unwind_Control_Block *ucbp, _uw

>>> return_address)

>>>      {

>>>        /* One of the predefined standard routines.  */

>>>        _uw idx = (*(_uw *) ucbp->pr_cache.ehtp >> 24) & 0xf;

>>> +#if __FDPIC__

>>> +      {

>>> +       struct funcdesc_t *funcdesc

>>> +         = (struct funcdesc_t *) __gnu_unwind_get_pr_addr (idx);

>>> +       if (funcdesc)

>>> +         {

>>> +           UCB_PR_ADDR (ucbp) = funcdesc->ptr;

>>> +           UCB_PR_GOT (ucbp) = funcdesc->got;

>>> +         }

>>> +       else

>>> +         {

>>> +           UCB_PR_ADDR (ucbp) = 0;

>>> +         }

>>> +      }

>>> +#else

>>>        UCB_PR_ADDR (ucbp) = __gnu_unwind_get_pr_addr (idx);

>>> +#endif

>>>        if (UCB_PR_ADDR (ucbp) == 0)

>>>          {

>>>            /* Failed */

>>> @@ -269,7 +292,13 @@ get_eit_entry (_Unwind_Control_Block *ucbp, _uw

>>> return_address)

>>>    else

>>>      {

>>>        /* Execute region offset to PR */

>>> +#if __FDPIC__

>>>        UCB_PR_ADDR (ucbp) = selfrel_offset31 (ucbp->pr_cache.ehtp);

>>> +      UCB_PR_GOT (ucbp)

>>> +       = (unsigned int) gnu_Unwind_Find_got ((_Unwind_Ptr)

>>> UCB_PR_ADDR (ucbp));

>>> +#else

>>> +      UCB_PR_ADDR (ucbp) = selfrel_offset31 (ucbp->pr_cache.ehtp);

>>> +#endif

>>>      }

>>>    return _URC_OK;

>>>  }

>>> @@ -291,14 +320,29 @@ unwind_phase2 (_Unwind_Control_Block * ucbp,

>>> phase2_vrs * vrs)

>>>        UCB_SAVED_CALLSITE_ADDR (ucbp) = VRS_PC(vrs);

>>>

>>>        /* Call the pr to decide what to do.  */

>>> +#if __FDPIC__

>>> +      {

>>> +       volatile struct funcdesc_t funcdesc;

>>> +       funcdesc.ptr = UCB_PR_ADDR (ucbp);

>>> +       funcdesc.got = UCB_PR_GOT (ucbp);

>>> +       pr_result = ((personality_routine) &funcdesc)

>>> +         (_US_UNWIND_FRAME_STARTING, ucbp, (_Unwind_Context *) vrs);

>>> +      }

>>> +#else

>>>        pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))

>>>          (_US_UNWIND_FRAME_STARTING, ucbp, (_Unwind_Context *) vrs);

>>> +#endif

>>>      }

>>>    while (pr_result == _URC_CONTINUE_UNWIND);

>>>

>>>    if (pr_result != _URC_INSTALL_CONTEXT)

>>>      abort();

>>>

>>> +#if __FDPIC__

>>> +      /* r9 could have been lost due to PLT jump.  Restore correct

>>> value.  */

>>> +      vrs->core.r[9] = gnu_Unwind_Find_got (VRS_PC (vrs));

>>> +#endif

>>> +

>>>    uw_restore_core_regs (vrs, &vrs->core);

>>>  }

>>>

>>> @@ -346,8 +390,18 @@ unwind_phase2_forced (_Unwind_Control_Block

>>> *ucbp, phase2_vrs *entry_vrs,

>>>            next_vrs = saved_vrs;

>>>

>>>            /* Call the pr to decide what to do.  */

>>> +#if __FDPIC__

>>> +         {

>>> +           volatile struct funcdesc_t funcdesc;

>>> +           funcdesc.ptr = UCB_PR_ADDR (ucbp);

>>> +           funcdesc.got = UCB_PR_GOT (ucbp);

>>> +           pr_result = ((personality_routine) &funcdesc)

>>> +             (action, ucbp, (void *) &next_vrs);

>>> +         }

>>> +#else

>>>            pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))

>>>              (action, ucbp, (void *) &next_vrs);

>>> +#endif

>>>

>>>            saved_vrs.prev_sp = VRS_SP (&next_vrs);

>>>          }

>>> @@ -384,6 +438,11 @@ unwind_phase2_forced (_Unwind_Control_Block

>>> *ucbp, phase2_vrs *entry_vrs,

>>>        return _URC_FAILURE;

>>>      }

>>>

>>> +#if __FDPIC__

>>> +  /* r9 could have been lost due to PLT jump.  Restore correct

>>> value.  */

>>> +  saved_vrs.core.r[9] = gnu_Unwind_Find_got (VRS_PC (&saved_vrs));

>>> +#endif

>>> +

>>>    uw_restore_core_regs (&saved_vrs, &saved_vrs.core);

>>>  }

>>>

>>> @@ -429,8 +488,18 @@ __gnu_Unwind_RaiseException

>>> (_Unwind_Control_Block * ucbp,

>>>          return _URC_FAILURE;

>>>

>>>        /* Call the pr to decide what to do.  */

>>> +#if __FDPIC__

>>> +      {

>>> +       volatile struct funcdesc_t funcdesc;

>>> +       funcdesc.ptr = UCB_PR_ADDR (ucbp);

>>> +       funcdesc.got = UCB_PR_GOT (ucbp);

>>> +       pr_result = ((personality_routine) &funcdesc)

>>> +         (_US_VIRTUAL_UNWIND_FRAME, ucbp, (void *) &saved_vrs);

>>> +      }

>>> +#else

>>>        pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))

>>>          (_US_VIRTUAL_UNWIND_FRAME, ucbp, (void *) &saved_vrs);

>>> +#endif

>>>      }

>>>    while (pr_result == _URC_CONTINUE_UNWIND);

>>>

>>> @@ -488,13 +557,27 @@ __gnu_Unwind_Resume (_Unwind_Control_Block *

>>> ucbp, phase2_vrs * entry_vrs)

>>>      }

>>>

>>>    /* Call the cached PR.  */

>>> +#if __FDPIC__

>>> +  {

>>> +    volatile struct funcdesc_t funcdesc;

>>> +    funcdesc.ptr = UCB_PR_ADDR (ucbp);

>>> +    funcdesc.got = UCB_PR_GOT (ucbp);

>>> +    pr_result = ((personality_routine) &funcdesc)

>>> +      (_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs);

>>> +  }

>>> +#else

>>>    pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))

>>>          (_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs);

>>> +#endif

>>>

>>>    switch (pr_result)

>>>      {

>>>      case _URC_INSTALL_CONTEXT:

>>>        /* Upload the registers to enter the landing pad.  */

>>> +#if __FDPIC__

>>> +      /* r9 could have been lost due to PLT jump.  Restore correct

>>> value.  */

>>> +      entry_vrs->core.r[9] = gnu_Unwind_Find_got (VRS_PC (entry_vrs));

>>> +#endif

>>>        uw_restore_core_regs (entry_vrs, &entry_vrs->core);

>>>

>>>      case _URC_CONTINUE_UNWIND:

>>> @@ -586,9 +669,20 @@ __gnu_Unwind_Backtrace(_Unwind_Trace_Fn trace,

>>> void * trace_argument,

>>>          }

>>>

>>>        /* Call the pr to decide what to do.  */

>>> +#if __FDPIC__

>>> +      {

>>> +       volatile struct funcdesc_t funcdesc;

>>> +       funcdesc.ptr = UCB_PR_ADDR (ucbp);

>>> +       funcdesc.got = UCB_PR_GOT (ucbp);

>>> +       code = ((personality_routine) &funcdesc)

>>> +         (_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND,

>>> +          ucbp, (void *) &saved_vrs);

>>> +      }

>>> +#else

>>>        code = ((personality_routine) UCB_PR_ADDR (ucbp))

>>>          (_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND,

>>>           ucbp, (void *) &saved_vrs);

>>> +#endif

>>>      }

>>>    while (code != _URC_END_OF_STACK

>>>           && code != _URC_FAILURE);

>>> diff --git a/libgcc/unwind-pe.h b/libgcc/unwind-pe.h

>>> index dd5ae95..c18dffe 100644

>>> --- a/libgcc/unwind-pe.h

>>> +++ b/libgcc/unwind-pe.h

>>> @@ -259,10 +259,25 @@ read_encoded_value_with_base (unsigned char

>>> encoding, _Unwind_Ptr base,

>>>

>>>        if (result != 0)

>>>          {

>>> +#if __FDPIC__

>>> +    if ((encoding & DW_EH_PE_pcrel) && (encoding & DW_EH_PE_indirect))

>>> +      {

>>> +       result += gnu_Unwind_Find_got ((_Unwind_Ptr) u);

>>> +       result = *(_Unwind_Internal_Ptr *) result;

>>> +      }

>>> +    else

>>> +      {

>>> +       result += ((encoding & 0x70) == DW_EH_PE_pcrel

>>> +                  ? (_Unwind_Internal_Ptr) u : base);

>>> +       if (encoding & DW_EH_PE_indirect)

>>> +         result = *(_Unwind_Internal_Ptr *) result;

>>> +      }

>>> +#else

>>>            result += ((encoding & 0x70) == DW_EH_PE_pcrel

>>>                       ? (_Unwind_Internal_Ptr) u : base);

>>>            if (encoding & DW_EH_PE_indirect)

>>>              result = *(_Unwind_Internal_Ptr *) result;

>>> +#endif

>>>          }

>>>      }

>>>

>>> diff --git a/libstdc++-v3/libsupc++/eh_personality.cc

>>> b/libstdc++-v3/libsupc++/eh_personality.cc

>>> index 1b336c7..138b606 100644

>>> --- a/libstdc++-v3/libsupc++/eh_personality.cc

>>> +++ b/libstdc++-v3/libsupc++/eh_personality.cc

>>> @@ -93,7 +93,13 @@ get_ttype_entry (lsda_header_info *info, _uleb128_t i)

>>>    _Unwind_Ptr ptr;

>>>

>>>    i *= size_of_encoded_value (info->ttype_encoding);

>>> -  read_encoded_value_with_base (info->ttype_encoding, info->ttype_base,

>>> +  read_encoded_value_with_base (

>>> +#if __FDPIC__

>>> +               (DW_EH_PE_pcrel | DW_EH_PE_indirect),

>>> +#else

>>> +               info->ttype_encoding,

>>> +#endif

>>> +               info->ttype_base,

>>>                                  info->TType - i, &ptr);

>>>

>>>    return reinterpret_cast<const std::type_info *>(ptr);

>>> --

>>> 2.6.3

>>>

>>

>

Patch

diff --git a/gcc/ginclude/unwind-arm-common.h b/gcc/ginclude/unwind-arm-common.h
index 8a1a919..150bd0f 100644
--- a/gcc/ginclude/unwind-arm-common.h
+++ b/gcc/ginclude/unwind-arm-common.h
@@ -91,7 +91,7 @@  extern "C" {
 	  _uw reserved2;  /* Personality routine address */
 	  _uw reserved3;  /* Saved callsite address */
 	  _uw reserved4;  /* Forced unwind stop arg */
-	  _uw reserved5;
+	  _uw reserved5;  /* Personality routine GOT value in FDPIC mode.  */
 	}
       unwinder_cache;
       /* Propagation barrier cache (valid after phase 1): */
diff --git a/libgcc/config/arm/linux-atomic.c b/libgcc/config/arm/linux-atomic.c
index d334c58..a20ad94 100644
--- a/libgcc/config/arm/linux-atomic.c
+++ b/libgcc/config/arm/linux-atomic.c
@@ -23,13 +23,99 @@  a copy of the GCC Runtime Library Exception along with this program;
 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 <http://www.gnu.org/licenses/>.  */
 
+#if defined(__ARM_ARCH_2__)
+# define __ARM_ARCH__ 2
+#endif
+
+#if defined(__ARM_ARCH_3__)
+# define __ARM_ARCH__ 3
+#endif
+
+#if defined(__ARM_ARCH_3M__) || defined(__ARM_ARCH_4__) \
+  || defined(__ARM_ARCH_4T__)
+/* We use __ARM_ARCH__ set to 4 here, but in reality it's any processor with
+   long multiply instructions.  That includes v3M.  */
+# define __ARM_ARCH__ 4
+#endif
+
+#if defined(__ARM_ARCH_5__) || defined(__ARM_ARCH_5T__) \
+  || defined(__ARM_ARCH_5E__) || defined(__ARM_ARCH_5TE__) \
+  || defined(__ARM_ARCH_5TEJ__)
+# define __ARM_ARCH__ 5
+#endif
+
+#if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) \
+  || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) \
+  || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) \
+  || defined(__ARM_ARCH_6M__)
+# define __ARM_ARCH__ 6
+#endif
+
+#if defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) \
+  || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) \
+  || defined(__ARM_ARCH_7EM__)
+# define __ARM_ARCH__ 7
+#endif
+
+#ifndef __ARM_ARCH__
+#error Unable to determine architecture.
+#endif
+
 /* Kernel helper for compare-and-exchange.  */
 typedef int (__kernel_cmpxchg_t) (int oldval, int newval, int *ptr);
+#if __FDPIC__
+#define __kernel_cmpxchg __fdpic_cmpxchg
+#else
 #define __kernel_cmpxchg (*(__kernel_cmpxchg_t *) 0xffff0fc0)
+#endif
 
 /* Kernel helper for memory barrier.  */
 typedef void (__kernel_dmb_t) (void);
+#if __FDPIC__
+#define __kernel_dmb __fdpic_dmb
+#else
 #define __kernel_dmb (*(__kernel_dmb_t *) 0xffff0fa0)
+#endif
+
+#if __FDPIC__
+static int __fdpic_cmpxchg (int oldval, int newval, int *ptr)
+{
+#if __ARM_ARCH__ < 6
+  #error architecture support not yet implemented
+  /* Use swap instruction (but is it always safe ? (interrupt?))  */
+#else
+  int result;
+
+  asm volatile ("1: ldrex r3, [%[ptr]]\n\t"
+		"subs  r3, r3, %[oldval]\n\t"
+		"itt eq\n\t"
+		"strexeq r3, %[newval], [%[ptr]]\n\t"
+		"teqeq r3, #1\n\t"
+		"it eq\n\t"
+		"beq 1b\n\t"
+		"rsbs  %[result], r3, #0\n\t"
+		: [result] "=r" (result)
+		: [oldval] "r" (oldval) , [newval] "r" (newval), [ptr] "r" (ptr)
+		: "r3");
+    return result;
+#endif
+}
+
+static void __fdpic_dmb ()
+{
+#if __ARM_ARCH__ < 6
+  /* No op? Perhaps flush write buffer ?  */
+  return ;
+#else
+ #if __ARM_ARCH__ >= 7
+  asm volatile ("dmb\n\t");
+ #elif __ARM_ARCH__ == 6
+  asm volatile ("mcr p15, 0, r0, c7, c10, 5\n\t");
+ #endif
+#endif
+}
+
+#endif
 
 /* Note: we implement byte, short and int versions of atomic operations using
    the above kernel helpers; see linux-atomic-64bit.c for "long long" (64-bit)
diff --git a/libgcc/config/arm/unwind-arm.h b/libgcc/config/arm/unwind-arm.h
index 9f7d3f2..a9598eb 100644
--- a/libgcc/config/arm/unwind-arm.h
+++ b/libgcc/config/arm/unwind-arm.h
@@ -36,6 +36,25 @@ 
 #ifdef __cplusplus
 extern "C" {
 #endif
+_Unwind_Ptr __attribute__((weak)) __gnu_Unwind_Find_got (_Unwind_Ptr);
+
+static inline _Unwind_Ptr gnu_Unwind_Find_got (_Unwind_Ptr ptr)
+{
+    _Unwind_Ptr res;
+
+    if (__gnu_Unwind_Find_got)
+	res =  __gnu_Unwind_Find_got (ptr);
+    else
+      {
+	asm volatile ("mov %[result], r9"
+		      : [result]"=r" (res)
+		      :
+		      :);
+    }
+
+    return res;
+}
+
   /* Decode an R_ARM_TARGET2 relocation.  */
   static inline _Unwind_Word
   _Unwind_decode_typeinfo_ptr (_Unwind_Word base __attribute__ ((unused)),
@@ -48,7 +67,12 @@  extern "C" {
       if (!tmp)
 	return 0;
 
-#if (defined(linux) && !defined(__uClinux__)) || defined(__NetBSD__) \
+#if __FDPIC__
+      /* For FDPIC, we store the offset of the GOT entry.  */
+      /* So, first get GOT from dynamic linker and then use indirect access.  */
+      tmp += gnu_Unwind_Find_got (ptr);
+      tmp = *(_Unwind_Word *) tmp;
+#elif (defined(linux) && !defined(__uClinux__)) || defined(__NetBSD__) \
     || defined(__FreeBSD__) || defined(__fuchsia__)
       /* Pc-relative indirect.  */
 #define _GLIBCXX_OVERRIDE_TTYPE_ENCODING (DW_EH_PE_pcrel | DW_EH_PE_indirect)
diff --git a/libgcc/unwind-arm-common.inc b/libgcc/unwind-arm-common.inc
index 76f8fc3..f5415c1 100644
--- a/libgcc/unwind-arm-common.inc
+++ b/libgcc/unwind-arm-common.inc
@@ -62,6 +62,7 @@  __gnu_Unwind_Find_exidx (_Unwind_Ptr, int *);
 #define UCB_PR_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved2)
 #define UCB_SAVED_CALLSITE_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved3)
 #define UCB_FORCED_STOP_ARG(ucbp) ((ucbp)->unwinder_cache.reserved4)
+#define UCB_PR_GOT(ucbp) ((ucbp)->unwinder_cache.reserved5)
 
 /* Unwind descriptors.  */
 
@@ -85,6 +86,12 @@  typedef struct __EIT_entry
   _uw content;
 } __EIT_entry;
 
+/* Only used in FDPIC case.  */
+struct funcdesc_t {
+    unsigned int ptr;
+    unsigned int got;
+};
+
 /* Assembly helper functions.  */
 
 /* Restore core register state.  Never returns.  */
@@ -259,7 +266,23 @@  get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address)
     {
       /* One of the predefined standard routines.  */
       _uw idx = (*(_uw *) ucbp->pr_cache.ehtp >> 24) & 0xf;
+#if __FDPIC__
+      {
+	struct funcdesc_t *funcdesc
+	  = (struct funcdesc_t *) __gnu_unwind_get_pr_addr (idx);
+	if (funcdesc)
+	  {
+	    UCB_PR_ADDR (ucbp) = funcdesc->ptr;
+	    UCB_PR_GOT (ucbp) = funcdesc->got;
+	  }
+	else
+	  {
+	    UCB_PR_ADDR (ucbp) = 0;
+	  }
+      }
+#else
       UCB_PR_ADDR (ucbp) = __gnu_unwind_get_pr_addr (idx);
+#endif
       if (UCB_PR_ADDR (ucbp) == 0)
 	{
 	  /* Failed */
@@ -269,7 +292,13 @@  get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address)
   else
     {
       /* Execute region offset to PR */
+#if __FDPIC__
       UCB_PR_ADDR (ucbp) = selfrel_offset31 (ucbp->pr_cache.ehtp);
+      UCB_PR_GOT (ucbp)
+	= (unsigned int) gnu_Unwind_Find_got ((_Unwind_Ptr) UCB_PR_ADDR (ucbp));
+#else
+      UCB_PR_ADDR (ucbp) = selfrel_offset31 (ucbp->pr_cache.ehtp);
+#endif
     }
   return _URC_OK;
 }
@@ -291,14 +320,29 @@  unwind_phase2 (_Unwind_Control_Block * ucbp, phase2_vrs * vrs)
       UCB_SAVED_CALLSITE_ADDR (ucbp) = VRS_PC(vrs);
 
       /* Call the pr to decide what to do.  */
+#if __FDPIC__
+      {
+	volatile struct funcdesc_t funcdesc;
+	funcdesc.ptr = UCB_PR_ADDR (ucbp);
+	funcdesc.got = UCB_PR_GOT (ucbp);
+	pr_result = ((personality_routine) &funcdesc)
+	  (_US_UNWIND_FRAME_STARTING, ucbp, (_Unwind_Context *) vrs);
+      }
+#else
       pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
 	(_US_UNWIND_FRAME_STARTING, ucbp, (_Unwind_Context *) vrs);
+#endif
     }
   while (pr_result == _URC_CONTINUE_UNWIND);
   
   if (pr_result != _URC_INSTALL_CONTEXT)
     abort();
 
+#if __FDPIC__
+      /* r9 could have been lost due to PLT jump.  Restore correct value.  */
+      vrs->core.r[9] = gnu_Unwind_Find_got (VRS_PC (vrs));
+#endif
+
   uw_restore_core_regs (vrs, &vrs->core);
 }
 
@@ -346,8 +390,18 @@  unwind_phase2_forced (_Unwind_Control_Block *ucbp, phase2_vrs *entry_vrs,
 	  next_vrs = saved_vrs;
 
 	  /* Call the pr to decide what to do.  */
+#if __FDPIC__
+	  {
+	    volatile struct funcdesc_t funcdesc;
+	    funcdesc.ptr = UCB_PR_ADDR (ucbp);
+	    funcdesc.got = UCB_PR_GOT (ucbp);
+	    pr_result = ((personality_routine) &funcdesc)
+	      (action, ucbp, (void *) &next_vrs);
+	  }
+#else
 	  pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
 	    (action, ucbp, (void *) &next_vrs);
+#endif
 
 	  saved_vrs.prev_sp = VRS_SP (&next_vrs);
 	}
@@ -384,6 +438,11 @@  unwind_phase2_forced (_Unwind_Control_Block *ucbp, phase2_vrs *entry_vrs,
       return _URC_FAILURE;
     }
 
+#if __FDPIC__
+  /* r9 could have been lost due to PLT jump.  Restore correct value.  */
+  saved_vrs.core.r[9] = gnu_Unwind_Find_got (VRS_PC (&saved_vrs));
+#endif
+
   uw_restore_core_regs (&saved_vrs, &saved_vrs.core);
 }
 
@@ -429,8 +488,18 @@  __gnu_Unwind_RaiseException (_Unwind_Control_Block * ucbp,
 	return _URC_FAILURE;
 
       /* Call the pr to decide what to do.  */
+#if __FDPIC__
+      {
+	volatile struct funcdesc_t funcdesc;
+	funcdesc.ptr = UCB_PR_ADDR (ucbp);
+	funcdesc.got = UCB_PR_GOT (ucbp);
+	pr_result = ((personality_routine) &funcdesc)
+	  (_US_VIRTUAL_UNWIND_FRAME, ucbp, (void *) &saved_vrs);
+      }
+#else
       pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
 	(_US_VIRTUAL_UNWIND_FRAME, ucbp, (void *) &saved_vrs);
+#endif
     }
   while (pr_result == _URC_CONTINUE_UNWIND);
 
@@ -488,13 +557,27 @@  __gnu_Unwind_Resume (_Unwind_Control_Block * ucbp, phase2_vrs * entry_vrs)
     }
 
   /* Call the cached PR.  */
+#if __FDPIC__
+  {
+    volatile struct funcdesc_t funcdesc;
+    funcdesc.ptr = UCB_PR_ADDR (ucbp);
+    funcdesc.got = UCB_PR_GOT (ucbp);
+    pr_result = ((personality_routine) &funcdesc)
+      (_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs);
+  }
+#else
   pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
 	(_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs);
+#endif
 
   switch (pr_result)
     {
     case _URC_INSTALL_CONTEXT:
       /* Upload the registers to enter the landing pad.  */
+#if __FDPIC__
+      /* r9 could have been lost due to PLT jump.  Restore correct value.  */
+      entry_vrs->core.r[9] = gnu_Unwind_Find_got (VRS_PC (entry_vrs));
+#endif
       uw_restore_core_regs (entry_vrs, &entry_vrs->core);
 
     case _URC_CONTINUE_UNWIND:
@@ -586,9 +669,20 @@  __gnu_Unwind_Backtrace(_Unwind_Trace_Fn trace, void * trace_argument,
 	}
 
       /* Call the pr to decide what to do.  */
+#if __FDPIC__
+      {
+	volatile struct funcdesc_t funcdesc;
+	funcdesc.ptr = UCB_PR_ADDR (ucbp);
+	funcdesc.got = UCB_PR_GOT (ucbp);
+	code = ((personality_routine) &funcdesc)
+	  (_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND,
+	   ucbp, (void *) &saved_vrs);
+      }
+#else
       code = ((personality_routine) UCB_PR_ADDR (ucbp))
 	(_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND, 
 	 ucbp, (void *) &saved_vrs);
+#endif
     }
   while (code != _URC_END_OF_STACK
 	 && code != _URC_FAILURE);
diff --git a/libgcc/unwind-pe.h b/libgcc/unwind-pe.h
index dd5ae95..c18dffe 100644
--- a/libgcc/unwind-pe.h
+++ b/libgcc/unwind-pe.h
@@ -259,10 +259,25 @@  read_encoded_value_with_base (unsigned char encoding, _Unwind_Ptr base,
 
       if (result != 0)
 	{
+#if __FDPIC__
+    if ((encoding & DW_EH_PE_pcrel) && (encoding & DW_EH_PE_indirect))
+      {
+	result += gnu_Unwind_Find_got ((_Unwind_Ptr) u);
+	result = *(_Unwind_Internal_Ptr *) result;
+      }
+    else
+      {
+	result += ((encoding & 0x70) == DW_EH_PE_pcrel
+		   ? (_Unwind_Internal_Ptr) u : base);
+	if (encoding & DW_EH_PE_indirect)
+	  result = *(_Unwind_Internal_Ptr *) result;
+      }
+#else
 	  result += ((encoding & 0x70) == DW_EH_PE_pcrel
 		     ? (_Unwind_Internal_Ptr) u : base);
 	  if (encoding & DW_EH_PE_indirect)
 	    result = *(_Unwind_Internal_Ptr *) result;
+#endif
 	}
     }
 
diff --git a/libstdc++-v3/libsupc++/eh_personality.cc b/libstdc++-v3/libsupc++/eh_personality.cc
index 1b336c7..138b606 100644
--- a/libstdc++-v3/libsupc++/eh_personality.cc
+++ b/libstdc++-v3/libsupc++/eh_personality.cc
@@ -93,7 +93,13 @@  get_ttype_entry (lsda_header_info *info, _uleb128_t i)
   _Unwind_Ptr ptr;
 
   i *= size_of_encoded_value (info->ttype_encoding);
-  read_encoded_value_with_base (info->ttype_encoding, info->ttype_base,
+  read_encoded_value_with_base (
+#if __FDPIC__
+		(DW_EH_PE_pcrel | DW_EH_PE_indirect),
+#else
+		info->ttype_encoding,
+#endif
+		info->ttype_base,
 				info->TType - i, &ptr);
 
   return reinterpret_cast<const std::type_info *>(ptr);