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[PATCH 10/12] Create debug_frame_hdr in target byte order
- From: Marcin Nowakowski <marcin dot nowakowski at imgtec dot com>
- To: <systemtap at sourceware dot org>
- Cc: Marcin Nowakowski <marcin dot nowakowski at imgtec dot com>
- Date: Tue, 11 Oct 2016 10:14:26 +0200
- Subject: [PATCH 10/12] Create debug_frame_hdr in target byte order
- Authentication-results: sourceware.org; auth=none
- References: <1476173668-30787-1-git-send-email-marcin.nowakowski@imgtec.com>
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
---
translate.cxx | 38 ++++++++++++++++++++++++++++----------
1 file changed, 28 insertions(+), 10 deletions(-)
diff --git a/translate.cxx b/translate.cxx
index f4c8332..21afccd 100644
--- a/translate.cxx
+++ b/translate.cxx
@@ -23,6 +23,7 @@
#include "stapregex.h"
#include "stringtable.h"
+#include <byteswap.h>
#include <cstdlib>
#include <iostream>
#include <set>
@@ -6062,6 +6063,17 @@ struct unwindsym_dump_context
set<string> undone_unwindsym_modules;
};
+static bool need_byte_swap_for_target (const unsigned char e_ident[])
+{
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ return (e_ident[EI_DATA] == ELFDATA2MSB);
+#elif __BYTE_ORDER == __BIG_ENDIAN
+ return (e_ident[EI_DATA] == ELFDATA2LSB);
+#else
+ #error Bad host __BYTE_ORDER
+#endif
+}
+
static void create_debug_frame_hdr (const unsigned char e_ident[],
Elf_Data *debug_frame,
void **debug_frame_hdr,
@@ -6081,6 +6093,12 @@ static void create_debug_frame_hdr (const unsigned char e_ident[],
// So there is no need to read the CIEs. And the size is either 4
// or 8, depending on the elf class from e_ident.
int size = (e_ident[EI_CLASS] == ELFCLASS32) ? 4 : 8;
+ bool need_byte_swap = need_byte_swap_for_target (e_ident);
+#define host_to_target_64(x) (need_byte_swap ? bswap_64((x)) : (x))
+#define host_to_target_32(x) (need_byte_swap ? bswap_32((x)) : (x))
+#define target_to_host_64(x) (need_byte_swap ? bswap_64((x)) : (x))
+#define target_to_host_32(x) (need_byte_swap ? bswap_32((x)) : (x))
+
int res = 0;
Dwarf_Off off = 0;
Dwarf_CFI_Entry entry;
@@ -6098,9 +6116,9 @@ static void create_debug_frame_hdr (const unsigned char e_ident[],
{
Dwarf_Addr addr;
if (size == 4)
- addr = (*((uint32_t *) entry.fde.start));
+ addr = target_to_host_32((*((uint32_t *) entry.fde.start)));
else
- addr = (*((uint64_t *) entry.fde.start));
+ addr = target_to_host_64((*((uint64_t *) entry.fde.start)));
fdes.insert(pair<Dwarf_Addr, Dwarf_Off>(addr, off));
}
}
@@ -6145,23 +6163,23 @@ static void create_debug_frame_hdr (const unsigned char e_ident[],
if (size == 4)
{
uint32_t *table = (uint32_t *)(hdr + 4);
- *table++ = (uint32_t) 0; // eh_frame_ptr, unused
- *table++ = (uint32_t) fdes.size();
+ *table++ = host_to_target_32 ((uint32_t) 0); // eh_frame_ptr, unused
+ *table++ = host_to_target_32 ((uint32_t) fdes.size());
for (it = fdes.begin(); it != fdes.end(); it++)
{
- *table++ = (*it).first;
- *table++ = (*it).second;
+ *table++ = host_to_target_32 ((*it).first);
+ *table++ = host_to_target_32 ((*it).second);
}
}
else
{
uint64_t *table = (uint64_t *)(hdr + 4);
- *table++ = (uint64_t) 0; // eh_frame_ptr, unused
- *table++ = (uint64_t) fdes.size();
+ *table++ = host_to_target_64 ((uint64_t) 0); // eh_frame_ptr, unused
+ *table++ = host_to_target_64 ((uint64_t) fdes.size());
for (it = fdes.begin(); it != fdes.end(); it++)
{
- *table++ = (*it).first;
- *table++ = (*it).second;
+ *table++ = host_to_target_64 ((*it).first);
+ *table++ = host_to_target_64 ((*it).second);
}
}
}
--
2.7.4