When restoring a function address, we also have to restore the FDPIC
register value (r9).
2018-XX-XX Christophe Lyon <christophe.l...@st.com>
Mickaël Guêné <mickael.gu...@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
+
+#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
