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Revert r201292 which relaxed the stack frame alignment requirements. 

This was primarily working around problems where we weren't able
to identify trap handlers for different environments -- but instead,
I'm working to make it easier to specify those trap handler function
names.

llvm-svn: 201366
This commit is contained in:
Jason Molenda 2014-02-13 23:29:36 +00:00
parent 1f3de49f37
commit abba74b4ee
4 changed files with 40 additions and 37 deletions
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22
lldb/source/Plugins/ABI/MacOSX-i386/ABIMacOSX_i386.cpp
View File

@ -235,12 +235,22 @@ ABIMacOSX_i386::GetRedZoneSize () const
ABISP
ABIMacOSX_i386::CreateInstance (const ArchSpec &arch)
{
static ABISP g_abi_sp;
if (arch.GetTriple().getArch() == llvm::Triple::x86)
{
if (!g_abi_sp)
g_abi_sp.reset (new ABIMacOSX_i386);
return g_abi_sp;
static ABISP g_abi_mac_sp;
static ABISP g_abi_other_sp;
if (arch.GetTriple().getArch() == llvm::Triple::x86)
{
if (arch.GetTriple().isOSDarwin())
{
if (!g_abi_mac_sp)
g_abi_mac_sp.reset (new ABIMacOSX_i386(true));
return g_abi_mac_sp;
}
else
{
if (!g_abi_other_sp)
g_abi_other_sp.reset (new ABIMacOSX_i386(false));
return g_abi_other_sp;
}
}
return ABISP();
}

37
lldb/source/Plugins/ABI/MacOSX-i386/ABIMacOSX_i386.h
View File

@ -71,25 +71,24 @@ public:
return true;
}
// The Darwin i386 ABI requires that stack frames be 16 byte aligned.
// When there is a trap handler on the stack, e.g. _sigtramp in userland
// code, we've seen that the stack pointer is often not aligned properly
// before the handler is invoked. This means that lldb will stop the unwind
// early -- before the function which caused the trap.
//
// To work around this, we relax that alignment to be just word-size (4-bytes).
// Whitelisting the trap handlers for user space would be easy (_sigtramp) but
// in other environments there can be a large number of different functions
// involved in async traps.
//
// If we were to enforce 16-byte alignment, we also need to relax to 4-byte
// alignment for non-darwin i386 targets.
virtual bool
CallFrameAddressIsValid (lldb::addr_t cfa)
{
// Make sure the stack call frame addresses are are 4 byte aligned
if (cfa & (4ull - 1ull))
return false; // Not 4 byte aligned
// Darwin call frame addresses must be 16-byte aligned, but other OS's
// only need 4-byte alignment. Otherwise the ABI matches, so we have
// this one minor override here.
if (target_is_darwin)
{
// Make sure the stack call frame addresses are are 16 byte aligned
if (cfa & (16ull - 1ull))
return false; // Not 16 byte aligned
}
else
{
// Make sure the stack call frame addresses are are 4 byte aligned
if (cfa & (4ull - 1ull))
return false; // Not 4 byte aligned
}
if (cfa == 0)
return false; // Zero is not a valid stack address
return true;
@ -140,7 +139,11 @@ protected:
RegisterIsCalleeSaved (const lldb_private::RegisterInfo *reg_info);
private:
ABIMacOSX_i386() : lldb_private::ABI() { } // Call CreateInstance instead.
ABIMacOSX_i386(bool is_darwin) : lldb_private::ABI(),
target_is_darwin(is_darwin)
{ } // Call CreateInstance instead.
bool target_is_darwin;
};

16
lldb/source/Plugins/ABI/SysV-x86_64/ABISysV_x86_64.h
View File

@ -68,22 +68,12 @@ public:
return true;
}
// The SysV x86_64 ABI requires that stack frames be 16 byte aligned.
// When there is a trap handler on the stack, e.g. _sigtramp in userland
// code, we've seen that the stack pointer is often not aligned properly
// before the handler is invoked. This means that lldb will stop the unwind
// early -- before the function which caused the trap.
//
// To work around this, we relax that alignment to be just word-size (8-bytes).
// Whitelisting the trap handlers for user space would be easy (_sigtramp) but
// in other environments there can be a large number of different functions
// involved in async traps.
virtual bool
CallFrameAddressIsValid (lldb::addr_t cfa)
{
// Make sure the stack call frame addresses are 8 byte aligned
if (cfa & (8ull - 1ull))
return false; // Not 8 byte aligned
// Make sure the stack call frame addresses are 16 byte aligned
if (cfa & (16ull - 1ull))
return false; // Not 16 byte aligned
if (cfa == 0)
return false; // Zero is not a valid stack address
return true;

2
lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp
View File

@ -482,7 +482,7 @@ DynamicLoaderPOSIXDYLD::GetThreadLocalData (const lldb::ModuleSP module, const l
Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));
if (log)
log->Printf("DynamicLoaderPOSIXDYLD::Performed TLS lookup: "
"module=%s, link_map=0x%" PRIx64 ", tp=0x%" PRIx64 ", modid=%" PRId64 ", tls_block=0x%" PRIx64 "\n",
"module=%s, link_map=0x%" PRIx64 ", tp=0x%" PRIx64 ", modid=%ld, tls_block=0x%" PRIx64 "\n",
mod->GetObjectName().AsCString(""), link_map, tp, (int64_t)modid, tls_block);
return tls_block;