Hey team elfutils,
This patch is for https://sourceware.org/bugzilla/show_bug.cgi?id=31447, and
it is ready for code review now 😀
Regards,
Di
From 5326db4241c15a4b2760d12bcc6b58aec86eda98 Mon Sep 17 00:00:00 2001
From: Di Chen <dic...@redhat.com>
Date: Sun, 7 Jul 2024 14:57:30 +0800
Subject: [PATCH] libdwelf: provide a public debug section relocation function
When opening an ET_REL file through libdwfl, we do resolve all
cross-debug-section relocations using __libdwfl_relocate().
This commit provide a public function for the above feature, so users
can make sure that ET_REL files can be handled by libdw.
Here is an example:
int main(int argc, char **argv) {
const char *fname = argv[1];
Elf *elf;
elf_version(EV_CURRENT);
int fd = open(argv[1], O_RDWR);
elf = elf_begin(fd, ELF_C_RDWR, NULL);
dwelf_relocation_debug_sections(elf, fname);
elf_update(elf, ELF_C_WRITE);
return 0;
}
https://sourceware.org/bugzilla/show_bug.cgi?id=31447
Signed-off-by: Di Chen <dic...@redhat.com>
---
libdw/libdw.map | 5 +
libdwelf/Makefile.am | 5 +-
libdwelf/dwelf_relocation_debug_sections.c | 389 +++++++++++++++++++++
libdwelf/libdwelf.h | 3 +
src/strip.c | 348 +-----------------
tests/Makefile.am | 5 +-
tests/dwelf_reloc_dbg_scn.c | 25 ++
tests/run-dwelf-reloc-dbg-scn.sh | 48 +++
tests/testfile-dwelf-reloc-dbg-scn.o.bz2 | Bin 0 -> 1088 bytes
9 files changed, 481 insertions(+), 347 deletions(-)
create mode 100644 libdwelf/dwelf_relocation_debug_sections.c
create mode 100644 tests/dwelf_reloc_dbg_scn.c
create mode 100755 tests/run-dwelf-reloc-dbg-scn.sh
create mode 100644 tests/testfile-dwelf-reloc-dbg-scn.o.bz2
diff --git a/libdw/libdw.map b/libdw/libdw.map
index 552588a9..529036f8 100644
--- a/libdw/libdw.map
+++ b/libdw/libdw.map
@@ -383,3 +383,8 @@ ELFUTILS_0.192 {
global:
dwfl_set_sysroot;
} ELFUTILS_0.191;
+
+ELFUTILS_0.193 {
+ global:
+ dwelf_relocation_debug_sections;
+} ELFUTILS_0.192;
diff --git a/libdwelf/Makefile.am b/libdwelf/Makefile.am
index a35a2873..a3d9cdd4 100644
--- a/libdwelf/Makefile.am
+++ b/libdwelf/Makefile.am
@@ -42,13 +42,14 @@ noinst_HEADERS = libdwelfP.h
libdwelf_a_SOURCES = dwelf_elf_gnu_debuglink.c dwelf_dwarf_gnu_debugaltlink.c \
dwelf_elf_gnu_build_id.c dwelf_scn_gnu_compressed_size.c \
dwelf_strtab.c dwelf_elf_begin.c \
- dwelf_elf_e_machine_string.c
+ dwelf_elf_e_machine_string.c \
+ dwelf_relocation_debug_sections.c
libdwelf = $(libdw)
libdw = ../libdw/libdw.so
libelf = ../libelf/libelf.so
-libebl = ../libebl/libebl.a
+libebl = ../libebl/libebl.a ../backends/libebl_backends.a
libeu = ../lib/libeu.a
libdwelf_pic_a_SOURCES =
diff --git a/libdwelf/dwelf_relocation_debug_sections.c b/libdwelf/dwelf_relocation_debug_sections.c
new file mode 100644
index 00000000..b2949124
--- /dev/null
+++ b/libdwelf/dwelf_relocation_debug_sections.c
@@ -0,0 +1,389 @@
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <assert.h>
+#include "libdwP.h"
+#include "libebl.h"
+
+#define INTERNAL_ERROR(fname) \
+ error_exit(0, _("%s: INTERNAL ERROR %d (%s): %s"), fname, __LINE__, \
+ PACKAGE_VERSION, elf_errmsg(-1))
+
+typedef uint8_t GElf_Byte;
+static int debug_fd = -1;
+static char *tmp_debug_fname = NULL;
+
+
+const char *
+secndx_name (Elf *elf, size_t ndx)
+{
+ size_t shstrndx;
+ GElf_Shdr mem;
+ Elf_Scn *sec = elf_getscn (elf, ndx);
+ GElf_Shdr *shdr = gelf_getshdr (sec, &mem);
+ if (shdr == NULL || elf_getshdrstrndx (elf, &shstrndx) < 0)
+ return "???";
+ return elf_strptr (elf, shstrndx, shdr->sh_name) ?: "???";
+}
+
+
+Elf_Data *
+get_xndxdata (Elf *elf, Elf_Scn *symscn)
+{
+ Elf_Data *xndxdata = NULL;
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (symscn, &shdr_mem);
+ if (shdr != NULL && shdr->sh_type == SHT_SYMTAB)
+ {
+ size_t scnndx = elf_ndxscn (symscn);
+ Elf_Scn *xndxscn = NULL;
+ while ((xndxscn = elf_nextscn (elf, xndxscn)) != NULL)
+ {
+ GElf_Shdr xndxshdr_mem;
+ GElf_Shdr *xndxshdr = gelf_getshdr (xndxscn, &xndxshdr_mem);
+
+ if (xndxshdr != NULL
+ && xndxshdr->sh_type == SHT_SYMTAB_SHNDX
+ && xndxshdr->sh_link == scnndx)
+ {
+ xndxdata = elf_getdata (xndxscn, NULL);
+ break;
+ }
+ }
+ }
+
+ return xndxdata;
+}
+
+
+void
+cleanup_debug (void)
+{
+ if (debug_fd >= 0)
+ {
+ if (tmp_debug_fname != NULL)
+ {
+ unlink (tmp_debug_fname);
+ free (tmp_debug_fname);
+ tmp_debug_fname = NULL;
+ }
+ close (debug_fd);
+ debug_fd = -1;
+ }
+}
+
+
+bool
+relocate (Elf *elf, GElf_Addr offset, const GElf_Sxword addend,
+ Elf_Data *tdata, unsigned int ei_data, const char *fname,
+ bool is_rela, GElf_Sym *sym, int addsub, Elf_Type type)
+{
+ /* These are the types we can relocate. */
+#define TYPES DO_TYPE (BYTE, Byte); DO_TYPE (HALF, Half); \
+ DO_TYPE (WORD, Word); DO_TYPE (SWORD, Sword); \
+ DO_TYPE (XWORD, Xword); DO_TYPE (SXWORD, Sxword)
+
+ size_t size;
+
+#define DO_TYPE(NAME, Name) GElf_##Name Name;
+ union { TYPES; } tmpbuf;
+#undef DO_TYPE
+
+ switch (type)
+ {
+#define DO_TYPE(NAME, Name) \
+ case ELF_T_##NAME: \
+ size = sizeof (GElf_##Name); \
+ tmpbuf.Name = 0; \
+ break;
+ TYPES;
+#undef DO_TYPE
+ default:
+ return false;
+ }
+
+ if (offset > tdata->d_size
+ || tdata->d_size - offset < size)
+ {
+ cleanup_debug ();
+ error_exit (0, _("bad relocation"));
+ }
+
+ /* When the symbol value is zero then for SHT_REL
+ sections this is all that needs to be checked.
+ The addend is contained in the original data at
+ the offset already. So if the (section) symbol
+ address is zero and the given addend is zero
+ just remove the relocation, it isn't needed
+ anymore. */
+ if (addend == 0 && sym->st_value == 0)
+ return true;
+
+ Elf_Data tmpdata =
+ {
+ .d_type = type,
+ .d_buf = &tmpbuf,
+ .d_size = size,
+ .d_version = EV_CURRENT,
+ };
+ Elf_Data rdata =
+ {
+ .d_type = type,
+ .d_buf = tdata->d_buf + offset,
+ .d_size = size,
+ .d_version = EV_CURRENT,
+ };
+
+ GElf_Addr value = sym->st_value;
+ if (is_rela)
+ {
+ /* For SHT_RELA sections we just take the
+ given addend and add it to the value. */
+ value += addend;
+ /* For ADD/SUB relocations we need to fetch the
+ current section contents. */
+ if (addsub != 0)
+ {
+ Elf_Data *d = gelf_xlatetom (elf, &tmpdata,
+ &rdata,
+ ei_data);
+ if (d == NULL)
+ INTERNAL_ERROR (fname);
+ assert (d == &tmpdata);
+ }
+ }
+ else
+ {
+ /* For SHT_REL sections we have to peek at
+ what is already in the section at the given
+ offset to get the addend. */
+ Elf_Data *d = gelf_xlatetom (elf, &tmpdata,
+ &rdata,
+ ei_data);
+ if (d == NULL)
+ INTERNAL_ERROR (fname);
+ assert (d == &tmpdata);
+ }
+
+ switch (type)
+ {
+#define DO_TYPE(NAME, Name) \
+ case ELF_T_##NAME: \
+ if (addsub < 0) \
+ tmpbuf.Name -= (GElf_##Name) value; \
+ else \
+ tmpbuf.Name += (GElf_##Name) value; \
+ break;
+ TYPES;
+#undef DO_TYPE
+ default:
+ abort ();
+ }
+
+ /* Now finally put in the new value. */
+ Elf_Data *s = gelf_xlatetof (elf, &rdata,
+ &tmpdata,
+ ei_data);
+ if (s == NULL)
+ INTERNAL_ERROR (fname);
+ assert (s == &rdata);
+
+ return true;
+}
+
+
+void dwelf_relocation_debug_sections (Elf *elf, const char *fname)
+{
+ size_t shstrndx;
+ if (elf_getshdrstrndx (elf, &shstrndx) < 0)
+ INTERNAL_ERROR (fname);
+
+ GElf_Ehdr ehdr_mem, *ehdr = gelf_getehdr (elf, &ehdr_mem);
+ if (ehdr == NULL)
+ {
+ // __libdwfl_seterrno (DWFL_E_LIBELF);
+ INTERNAL_ERROR (fname);
+ }
+ const unsigned int ei_data = ehdr->e_ident[EI_DATA];
+
+ Ebl *ebl = ebl_openbackend (elf);
+ if (ebl == NULL)
+ {
+ // __libdwfl_seterrno (DWFL_E_LIBEBL);
+ INTERNAL_ERROR (fname);
+ }
+
+ Elf_Scn *scn = NULL;
+ while ((scn = elf_nextscn (elf, scn)) != NULL)
+ {
+ /* We need the actual section and header from the elf
+ not just the cached original in shdr_info because we
+ might want to change the size. */
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+
+ if (shdr != NULL
+ && (shdr->sh_type == SHT_REL || shdr->sh_type == SHT_RELA))
+ {
+ /* Make sure that this relocation section points to a
+ section to relocate with contents, that isn't
+ allocated and that is a debug section. */
+ Elf_Scn *tscn = elf_getscn (elf, shdr->sh_info);
+ GElf_Shdr tshdr_mem;
+ GElf_Shdr *tshdr = gelf_getshdr (tscn, &tshdr_mem);
+ if (tshdr == NULL
+ || tshdr->sh_type == SHT_NOBITS
+ || tshdr->sh_size == 0
+ || (tshdr->sh_flags & SHF_ALLOC) != 0)
+ continue;
+
+ const char *tname = elf_strptr (elf, shstrndx,
+ tshdr->sh_name);
+ if (! tname || ! ebl_debugscn_p (ebl, tname))
+ continue;
+
+ /* OK, lets relocate all trivial cross debug section
+ relocations. */
+ Elf_Data *reldata = elf_getdata (scn, NULL);
+ if (reldata == NULL || reldata->d_buf == NULL)
+ INTERNAL_ERROR (fname);
+
+ /* Make sure we adjust the uncompressed debug data
+ (and recompress if necessary at the end). */
+ GElf_Chdr tchdr;
+ int tcompress_type = 0;
+ bool is_gnu_compressed = false;
+ if (startswith (tname, ".zdebug"))
+ {
+ is_gnu_compressed = true;
+ if (elf_compress_gnu (tscn, 0, 0) != 1)
+ INTERNAL_ERROR (fname);
+ }
+ else
+ {
+ if (gelf_getchdr (tscn, &tchdr) != NULL)
+ {
+ tcompress_type = tchdr.ch_type;
+ if (elf_compress (tscn, 0, 0) != 1)
+ INTERNAL_ERROR (fname);
+ }
+ }
+
+ Elf_Data *tdata = elf_getdata (tscn, NULL);
+ if (tdata == NULL || tdata->d_buf == NULL
+ || tdata->d_type != ELF_T_BYTE)
+ INTERNAL_ERROR (fname);
+
+ /* Pick up the symbol table and shndx table to
+ resolve relocation symbol indexes. */
+ Elf64_Word symt = shdr->sh_link;
+ Elf_Data *symdata, *xndxdata;
+ Elf_Scn * symscn = elf_getscn (elf, symt);
+ symdata = elf_getdata (symscn, NULL);
+ xndxdata = get_xndxdata (elf, symscn);
+ if (symdata == NULL)
+ INTERNAL_ERROR (fname);
+
+ if (shdr->sh_entsize == 0)
+ INTERNAL_ERROR (fname);
+
+ size_t nrels = shdr->sh_size / shdr->sh_entsize;
+ size_t next = 0;
+ const bool is_rela = (shdr->sh_type == SHT_RELA);
+
+ for (size_t relidx = 0; relidx < nrels; ++relidx)
+ {
+ int rtype, symndx, offset, addend;
+ union { GElf_Rela rela; GElf_Rel rel; } mem;
+ void *rel_p; /* Pointer to either rela or rel above */
+
+ if (is_rela)
+ {
+ GElf_Rela *r = gelf_getrela (reldata, relidx, &mem.rela);
+ if (r == NULL)
+ INTERNAL_ERROR (fname);
+ offset = r->r_offset;
+ addend = r->r_addend;
+ rtype = GELF_R_TYPE (r->r_info);
+ symndx = GELF_R_SYM (r->r_info);
+ rel_p = r;
+ }
+ else
+ {
+ GElf_Rel *r = gelf_getrel (reldata, relidx, &mem.rel);
+ if (r == NULL)
+ INTERNAL_ERROR (fname);
+ offset = r->r_offset;
+ addend = 0;
+ rtype = GELF_R_TYPE (r->r_info);
+ symndx = GELF_R_SYM (r->r_info);
+ rel_p = r;
+ }
+
+ /* R_*_NONE relocs can always just be removed. */
+ if (rtype == 0)
+ continue;
+
+ /* We only do simple absolute relocations. */
+ int addsub = 0;
+ Elf_Type type = ebl_reloc_simple_type (ebl, rtype, &addsub);
+ if (type == ELF_T_NUM)
+ goto relocate_failed;
+
+ /* And only for relocations against other debug sections. */
+ GElf_Sym sym_mem;
+ Elf32_Word xndx;
+ GElf_Sym *sym = gelf_getsymshndx (symdata, xndxdata,
+ symndx, &sym_mem,
+ &xndx);
+ if (sym == NULL)
+ INTERNAL_ERROR (fname);
+ Elf32_Word sec = (sym->st_shndx == SHN_XINDEX
+ ? xndx : sym->st_shndx);
+
+ bool dbg_scn = ebl_debugscn_p (ebl, secndx_name (elf, sec));
+
+ if (!dbg_scn)
+ goto relocate_failed;
+
+ if (! relocate (elf, offset, addend,
+ tdata, ei_data, fname, is_rela,
+ sym, addsub, type))
+ goto relocate_failed;
+
+ continue; /* Next */
+
+relocate_failed:
+ if (relidx != next)
+ {
+ int updated;
+ if (is_rela)
+ updated = gelf_update_rela (reldata, next, rel_p);
+ else
+ updated = gelf_update_rel (reldata, next, rel_p);
+ if (updated == 0)
+ INTERNAL_ERROR (fname);
+ }
+ ++next;
+ }
+
+ nrels = next;
+ shdr->sh_size = reldata->d_size = nrels * shdr->sh_entsize;
+ if (gelf_update_shdr (scn, shdr) == 0)
+ INTERNAL_ERROR (fname);
+
+ if (is_gnu_compressed)
+ {
+ if (elf_compress_gnu (tscn, 1, ELF_CHF_FORCE) != 1)
+ INTERNAL_ERROR (fname);
+ }
+ else if (tcompress_type != 0)
+ {
+ if (elf_compress (tscn, tcompress_type, ELF_CHF_FORCE) != 1)
+ INTERNAL_ERROR (fname);
+ }
+ }
+ }
+
+}
diff --git a/libdwelf/libdwelf.h b/libdwelf/libdwelf.h
index 263ca60e..89936bf8 100644
--- a/libdwelf/libdwelf.h
+++ b/libdwelf/libdwelf.h
@@ -140,6 +140,9 @@ extern Elf *dwelf_elf_begin (int fd);
value, or NULL if the given number isn't currently known. */
extern const char *dwelf_elf_e_machine_string (int machine);
+/* Provide a public debug section relocation function. */
+extern void dwelf_relocation_debug_sections (Elf *elf, const char *fname);
+
#ifdef __cplusplus
}
#endif
diff --git a/src/strip.c b/src/strip.c
index 403e0f6f..b46966e6 100644
--- a/src/strip.c
+++ b/src/strip.c
@@ -367,46 +367,6 @@ parse_opt (int key, char *arg, struct argp_state *state)
return 0;
}
-static const char *
-secndx_name (Elf *elf, size_t ndx)
-{
- size_t shstrndx;
- GElf_Shdr mem;
- Elf_Scn *sec = elf_getscn (elf, ndx);
- GElf_Shdr *shdr = gelf_getshdr (sec, &mem);
- if (shdr == NULL || elf_getshdrstrndx (elf, &shstrndx) < 0)
- return "???";
- return elf_strptr (elf, shstrndx, shdr->sh_name) ?: "???";
-}
-
-/* Get the extended section index table data for a symbol table section. */
-static Elf_Data *
-get_xndxdata (Elf *elf, Elf_Scn *symscn)
-{
- Elf_Data *xndxdata = NULL;
- GElf_Shdr shdr_mem;
- GElf_Shdr *shdr = gelf_getshdr (symscn, &shdr_mem);
- if (shdr != NULL && shdr->sh_type == SHT_SYMTAB)
- {
- size_t scnndx = elf_ndxscn (symscn);
- Elf_Scn *xndxscn = NULL;
- while ((xndxscn = elf_nextscn (elf, xndxscn)) != NULL)
- {
- GElf_Shdr xndxshdr_mem;
- GElf_Shdr *xndxshdr = gelf_getshdr (xndxscn, &xndxshdr_mem);
-
- if (xndxshdr != NULL
- && xndxshdr->sh_type == SHT_SYMTAB_SHNDX
- && xndxshdr->sh_link == scnndx)
- {
- xndxdata = elf_getdata (xndxscn, NULL);
- break;
- }
- }
- }
-
- return xndxdata;
-}
/* Updates the shdrstrndx for the given Elf by updating the Ehdr and
possibly the section zero extension field. Returns zero on success. */
@@ -440,306 +400,6 @@ update_shdrstrndx (Elf *elf, size_t shdrstrndx)
}
-/* Apply one relocation. Returns true when trivial
- relocation actually done. */
-static bool
-relocate (Elf *elf, GElf_Addr offset, const GElf_Sxword addend,
- Elf_Data *tdata, unsigned int ei_data, const char *fname,
- bool is_rela, GElf_Sym *sym, int addsub, Elf_Type type)
-{
- /* These are the types we can relocate. */
-#define TYPES DO_TYPE (BYTE, Byte); DO_TYPE (HALF, Half); \
- DO_TYPE (WORD, Word); DO_TYPE (SWORD, Sword); \
- DO_TYPE (XWORD, Xword); DO_TYPE (SXWORD, Sxword)
-
- size_t size;
-
-#define DO_TYPE(NAME, Name) GElf_##Name Name;
- union { TYPES; } tmpbuf;
-#undef DO_TYPE
-
- switch (type)
- {
-#define DO_TYPE(NAME, Name) \
- case ELF_T_##NAME: \
- size = sizeof (GElf_##Name); \
- tmpbuf.Name = 0; \
- break;
- TYPES;
-#undef DO_TYPE
- default:
- return false;
- }
-
- if (offset > tdata->d_size
- || tdata->d_size - offset < size)
- {
- cleanup_debug ();
- error_exit (0, _("bad relocation"));
- }
-
- /* When the symbol value is zero then for SHT_REL
- sections this is all that needs to be checked.
- The addend is contained in the original data at
- the offset already. So if the (section) symbol
- address is zero and the given addend is zero
- just remove the relocation, it isn't needed
- anymore. */
- if (addend == 0 && sym->st_value == 0)
- return true;
-
- Elf_Data tmpdata =
- {
- .d_type = type,
- .d_buf = &tmpbuf,
- .d_size = size,
- .d_version = EV_CURRENT,
- };
- Elf_Data rdata =
- {
- .d_type = type,
- .d_buf = tdata->d_buf + offset,
- .d_size = size,
- .d_version = EV_CURRENT,
- };
-
- GElf_Addr value = sym->st_value;
- if (is_rela)
- {
- /* For SHT_RELA sections we just take the
- given addend and add it to the value. */
- value += addend;
- /* For ADD/SUB relocations we need to fetch the
- current section contents. */
- if (addsub != 0)
- {
- Elf_Data *d = gelf_xlatetom (elf, &tmpdata,
- &rdata,
- ei_data);
- if (d == NULL)
- INTERNAL_ERROR (fname);
- assert (d == &tmpdata);
- }
- }
- else
- {
- /* For SHT_REL sections we have to peek at
- what is already in the section at the given
- offset to get the addend. */
- Elf_Data *d = gelf_xlatetom (elf, &tmpdata,
- &rdata,
- ei_data);
- if (d == NULL)
- INTERNAL_ERROR (fname);
- assert (d == &tmpdata);
- }
-
- switch (type)
- {
-#define DO_TYPE(NAME, Name) \
- case ELF_T_##NAME: \
- if (addsub < 0) \
- tmpbuf.Name -= (GElf_##Name) value; \
- else \
- tmpbuf.Name += (GElf_##Name) value; \
- break;
- TYPES;
-#undef DO_TYPE
- default:
- abort ();
- }
-
- /* Now finally put in the new value. */
- Elf_Data *s = gelf_xlatetof (elf, &rdata,
- &tmpdata,
- ei_data);
- if (s == NULL)
- INTERNAL_ERROR (fname);
- assert (s == &rdata);
-
- return true;
-}
-
-/* Remove any relocations between debug sections in ET_REL
- for the debug file when requested. These relocations are always
- zero based between the unallocated sections. */
-static void
-remove_debug_relocations (Ebl *ebl, Elf *elf, GElf_Ehdr *ehdr,
- const char *fname, size_t shstrndx)
-{
- Elf_Scn *scn = NULL;
- while ((scn = elf_nextscn (elf, scn)) != NULL)
- {
- /* We need the actual section and header from the elf
- not just the cached original in shdr_info because we
- might want to change the size. */
- GElf_Shdr shdr_mem;
- GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
- if (shdr != NULL
- && (shdr->sh_type == SHT_REL || shdr->sh_type == SHT_RELA))
- {
- /* Make sure that this relocation section points to a
- section to relocate with contents, that isn't
- allocated and that is a debug section. */
- Elf_Scn *tscn = elf_getscn (elf, shdr->sh_info);
- GElf_Shdr tshdr_mem;
- GElf_Shdr *tshdr = gelf_getshdr (tscn, &tshdr_mem);
- if (tshdr == NULL
- || tshdr->sh_type == SHT_NOBITS
- || tshdr->sh_size == 0
- || (tshdr->sh_flags & SHF_ALLOC) != 0)
- continue;
-
- const char *tname = elf_strptr (elf, shstrndx,
- tshdr->sh_name);
- if (! tname || ! ebl_debugscn_p (ebl, tname))
- continue;
-
- /* OK, lets relocate all trivial cross debug section
- relocations. */
- Elf_Data *reldata = elf_getdata (scn, NULL);
- if (reldata == NULL || reldata->d_buf == NULL)
- INTERNAL_ERROR (fname);
-
- /* Make sure we adjust the uncompressed debug data
- (and recompress if necessary at the end). */
- GElf_Chdr tchdr;
- int tcompress_type = 0;
- bool is_gnu_compressed = false;
- if (startswith (tname, ".zdebug"))
- {
- is_gnu_compressed = true;
- if (elf_compress_gnu (tscn, 0, 0) != 1)
- INTERNAL_ERROR (fname);
- }
- else
- {
- if (gelf_getchdr (tscn, &tchdr) != NULL)
- {
- tcompress_type = tchdr.ch_type;
- if (elf_compress (tscn, 0, 0) != 1)
- INTERNAL_ERROR (fname);
- }
- }
-
- Elf_Data *tdata = elf_getdata (tscn, NULL);
- if (tdata == NULL || tdata->d_buf == NULL
- || tdata->d_type != ELF_T_BYTE)
- INTERNAL_ERROR (fname);
-
- /* Pick up the symbol table and shndx table to
- resolve relocation symbol indexes. */
- Elf64_Word symt = shdr->sh_link;
- Elf_Data *symdata, *xndxdata;
- Elf_Scn * symscn = elf_getscn (elf, symt);
- symdata = elf_getdata (symscn, NULL);
- xndxdata = get_xndxdata (elf, symscn);
- if (symdata == NULL)
- INTERNAL_ERROR (fname);
-
- if (shdr->sh_entsize == 0)
- INTERNAL_ERROR (fname);
-
- size_t nrels = shdr->sh_size / shdr->sh_entsize;
- size_t next = 0;
- const bool is_rela = (shdr->sh_type == SHT_RELA);
- const unsigned int ei_data = ehdr->e_ident[EI_DATA];
-
- for (size_t relidx = 0; relidx < nrels; ++relidx)
- {
- int rtype, symndx, offset, addend;
- union { GElf_Rela rela; GElf_Rel rel; } mem;
- void *rel_p; /* Pointer to either rela or rel above */
-
- if (is_rela)
- {
- GElf_Rela *r = gelf_getrela (reldata, relidx, &mem.rela);
- if (r == NULL)
- INTERNAL_ERROR (fname);
- offset = r->r_offset;
- addend = r->r_addend;
- rtype = GELF_R_TYPE (r->r_info);
- symndx = GELF_R_SYM (r->r_info);
- rel_p = r;
- }
- else
- {
- GElf_Rel *r = gelf_getrel (reldata, relidx, &mem.rel);
- if (r == NULL)
- INTERNAL_ERROR (fname);
- offset = r->r_offset;
- addend = 0;
- rtype = GELF_R_TYPE (r->r_info);
- symndx = GELF_R_SYM (r->r_info);
- rel_p = r;
- }
-
- /* R_*_NONE relocs can always just be removed. */
- if (rtype == 0)
- continue;
-
- /* We only do simple absolute relocations. */
- int addsub = 0;
- Elf_Type type = ebl_reloc_simple_type (ebl, rtype, &addsub);
- if (type == ELF_T_NUM)
- goto relocate_failed;
-
- /* And only for relocations against other debug sections. */
- GElf_Sym sym_mem;
- Elf32_Word xndx;
- GElf_Sym *sym = gelf_getsymshndx (symdata, xndxdata,
- symndx, &sym_mem,
- &xndx);
- if (sym == NULL)
- INTERNAL_ERROR (fname);
- Elf32_Word sec = (sym->st_shndx == SHN_XINDEX
- ? xndx : sym->st_shndx);
-
- bool dbg_scn = ebl_debugscn_p (ebl, secndx_name (elf, sec));
-
- if (!dbg_scn)
- goto relocate_failed;
-
- if (! relocate (elf, offset, addend,
- tdata, ei_data, fname, is_rela,
- sym, addsub, type))
- goto relocate_failed;
-
- continue; /* Next */
-
-relocate_failed:
- if (relidx != next)
- {
- int updated;
- if (is_rela)
- updated = gelf_update_rela (reldata, next, rel_p);
- else
- updated = gelf_update_rel (reldata, next, rel_p);
- if (updated == 0)
- INTERNAL_ERROR (fname);
- }
- ++next;
- }
-
- nrels = next;
- shdr->sh_size = reldata->d_size = nrels * shdr->sh_entsize;
- if (gelf_update_shdr (scn, shdr) == 0)
- INTERNAL_ERROR (fname);
-
- if (is_gnu_compressed)
- {
- if (elf_compress_gnu (tscn, 1, ELF_CHF_FORCE) != 1)
- INTERNAL_ERROR (fname);
- }
- else if (tcompress_type != 0)
- {
- if (elf_compress (tscn, tcompress_type, ELF_CHF_FORCE) != 1)
- INTERNAL_ERROR (fname);
- }
- }
- }
-}
-
static int
process_file (const char *fname)
{
@@ -839,7 +499,7 @@ process_file (const char *fname)
/* Processing for --reloc-debug-sections-only. */
static int
-handle_debug_relocs (Elf *elf, Ebl *ebl, Elf *new_elf,
+handle_debug_relocs (Elf *elf, Elf *new_elf,
GElf_Ehdr *ehdr, const char *fname, size_t shstrndx,
GElf_Off *last_offset, GElf_Xword *last_size)
{
@@ -911,7 +571,7 @@ handle_debug_relocs (Elf *elf, Ebl *ebl, Elf *new_elf,
}
/* Adjust the relocation sections. */
- remove_debug_relocations (ebl, new_elf, ehdr, fname, shstrndx);
+ dwelf_relocation_debug_sections (new_elf, fname);
/* Adjust the offsets of the non-allocated sections, so they come after
the allocated sections. */
@@ -1139,7 +799,7 @@ handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
if (reloc_debug_only)
{
- if (handle_debug_relocs (elf, ebl, newelf, ehdr, fname, shstrndx,
+ if (handle_debug_relocs (elf, newelf, ehdr, fname, shstrndx,
&lastsec_offset, &lastsec_size) != 0)
{
result = 1;
@@ -2457,7 +2117,7 @@ handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
zero based between the unallocated sections. */
if (debug_fname != NULL && removing_sections
&& reloc_debug && ehdr->e_type == ET_REL)
- remove_debug_relocations (ebl, debugelf, ehdr, fname, shstrndx);
+ dwelf_relocation_debug_sections (debugelf, fname);
/* Now that we have done all adjustments to the data,
we can actually write out the debug file. */
diff --git a/tests/Makefile.am b/tests/Makefile.am
index cdb2d405..69cfc1ba 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -59,7 +59,7 @@ check_PROGRAMS = arextract arsymtest newfile saridx scnnames sectiondump \
get-units-invalid get-units-split attr-integrate-skel \
all-dwarf-ranges unit-info next_cfi \
elfcopy addsections xlate_notes elfrdwrnop \
- dwelf_elf_e_machine_string \
+ dwelf_elf_e_machine_string dwelf_reloc_dbg_scn\
getphdrnum leb128 read_unaligned \
msg_tst system-elf-libelf-test system-elf-gelf-test \
nvidia_extended_linemap_libdw elf-print-reloc-syms \
@@ -205,6 +205,7 @@ TESTS = run-arextract.sh run-arsymtest.sh run-ar.sh newfile test-nlist \
run-strip-version.sh run-xlate-note.sh \
run-readelf-discr.sh \
run-dwelf_elf_e_machine_string.sh \
+ run-dwelf-reloc-dbg-scn.sh \
run-elfclassify.sh run-elfclassify-self.sh \
run-disasm-riscv64.sh \
run-pt_gnu_prop-tests.sh \
@@ -575,6 +576,7 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh run-ar.sh \
run-readelf-discr.sh \
testfile-rng.debug.bz2 testfile-urng.debug.bz2 \
run-dwelf_elf_e_machine_string.sh \
+ run-dwelf-reloc-dbg-scn.sh testfile-dwelf-reloc-dbg-scn.o.bz2 \
run-elfclassify.sh run-elfclassify-self.sh \
run-disasm-riscv64.sh \
testfile-riscv64-dis1.o.bz2 testfile-riscv64-dis1.expect.bz2 \
@@ -851,6 +853,7 @@ debuginfod_build_id_find_LDADD = $(libelf) $(libdw)
xlate_notes_LDADD = $(libelf)
elfrdwrnop_LDADD = $(libelf)
dwelf_elf_e_machine_string_LDADD = $(libelf) $(libdw)
+dwelf_reloc_dbg_scn_LDADD = $(libelf) $(libdw)
getphdrnum_LDADD = $(libelf) $(libdw)
leb128_LDADD = $(libelf) $(libdw)
read_unaligned_LDADD = $(libelf) $(libdw)
diff --git a/tests/dwelf_reloc_dbg_scn.c b/tests/dwelf_reloc_dbg_scn.c
new file mode 100644
index 00000000..bef58c01
--- /dev/null
+++ b/tests/dwelf_reloc_dbg_scn.c
@@ -0,0 +1,25 @@
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <err.h>
+#include <fcntl.h>
+#include ELFUTILS_HEADER(dw)
+#include ELFUTILS_HEADER(dwelf)
+#include <stdio.h>
+#include <unistd.h>
+
+int main(int /*argc*/, char **argv) {
+ const char *fname = argv[1];
+
+ Elf *elf;
+ elf_version(EV_CURRENT);
+ int fd = open(argv[1], O_RDWR);
+
+ elf = elf_begin(fd, ELF_C_RDWR, NULL);
+
+ dwelf_relocation_debug_sections(elf, fname);
+ elf_update(elf, ELF_C_WRITE);
+
+ return 0;
+}
diff --git a/tests/run-dwelf-reloc-dbg-scn.sh b/tests/run-dwelf-reloc-dbg-scn.sh
new file mode 100755
index 00000000..537a46f6
--- /dev/null
+++ b/tests/run-dwelf-reloc-dbg-scn.sh
@@ -0,0 +1,48 @@
+#! /usr/bin/env bash
+# Copyright (C) 2024 Red Hat, Inc.
+# This file is part of elfutils.
+#
+# This file is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# elfutils is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+. $srcdir/test-subr.sh
+
+testfiles testfile-dwelf-reloc-dbg-scn.o
+
+testrun_compare ${abs_builddir}/allfcts testfile-dwelf-reloc-dbg-scn.o <<\EOF
+qq.c/qq.c:6:GNU C17 14.2.1 20240801 (Red Hat 14.2.1-1) -mtune=generic -march=x86-64 -g
+qq.c/qq.c:1:add
+EOF
+
+testrun ${abs_builddir}/dwelf_reloc_dbg_scn testfile-dwelf-reloc-dbg-scn.o
+
+testrun_compare ${abs_builddir}/allfcts testfile-dwelf-reloc-dbg-scn.o <<\EOF
+/home/dichen/elfutils/tests/qq.c:6:main
+/home/dichen/elfutils/tests/qq.c:1:add
+EOF
+
+# = qq.c =
+# int add (int a, int b)
+# {
+# return a+b;
+# }
+#
+# int main()
+# {
+# return 0;
+# }
+
+# Using gcc (GCC) 14.2.1 20240801 (Red Hat 14.2.1-1)
+# gcc -g -c qq.c -o testfile-dwelf-reloc-dbg-scn.o
+
+exit 0
diff --git a/tests/testfile-dwelf-reloc-dbg-scn.o.bz2 b/tests/testfile-dwelf-reloc-dbg-scn.o.bz2
new file mode 100644
index 0000000000000000000000000000000000000000..2f7ca9b63adb5afc4e7b454c2531f328041de010
GIT binary patch
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GX{dalrP>4l
literal 0
HcmV?d00001
--
2.45.2
