* [PATCH 1/2] debugedit: Track active CU
@ 2024-05-19 21:05 Mark Wielaard
2024-05-19 21:05 ` [PATCH 2/2] debugedit: Handle DW_MACRO_{define,undef}_strx Mark Wielaard
2024-05-22 13:52 ` [PATCH 1/2] debugedit: Track active CU Mark Wielaard
0 siblings, 2 replies; 4+ messages in thread
From: Mark Wielaard @ 2024-05-19 21:05 UTC (permalink / raw)
To: debugedit; +Cc: Mark Wielaard
The current CU is tracked indirectly by having static variables for
ptr_size, cu_version and str_offsets_base. These are used to
process/skip forms and resolve strx forms. Put all three in a new
struct CU which must be passed to do_read_str_form_relocated,
skip_form, edit_strp and edit_attributes. The struct CU can then also
be used when parsing the line table string forms.
This should make .debug_line tables which use strx forms work (no
producers have been found that use those though).
Signed-off-by: Mark Wielaard <mark@klomp.org>
---
tools/debugedit.c | 127 ++++++++++++++++++++++++++++------------------
1 file changed, 78 insertions(+), 49 deletions(-)
diff --git a/tools/debugedit.c b/tools/debugedit.c
index 1307a149de8b..6f93fb702876 100644
--- a/tools/debugedit.c
+++ b/tools/debugedit.c
@@ -161,6 +161,8 @@ struct strings
struct line_table
{
+ struct CU *cu; /* (first) CU that references this table. */
+
size_t old_idx; /* Original offset. */
size_t new_idx; /* Offset in new debug_line section. */
ssize_t size_diff; /* Difference in (header) size. */
@@ -191,6 +193,16 @@ struct debug_lines
char *line_buf; /* New Elf_Data d_buf. */
};
+struct CU
+{
+ int ptr_size;
+ int cu_version;
+ /* The offset into the .debug_str_offsets section for this CU. */
+ uint32_t str_offsets_base;
+
+ struct CU *next;
+};
+
typedef struct
{
Elf *elf;
@@ -201,6 +213,10 @@ typedef struct
size_t phnum;
struct strings debug_str, debug_line_str;
struct debug_lines lines;
+ /* List of CUs that keeps track of version, ptr_size,
+ str_offsets_base, etc. so other structures, like macros, can use
+ those properties for parsing. */
+ struct CU *cus;
GElf_Shdr shdr[0];
} DSO;
@@ -292,6 +308,17 @@ destroy_lines (struct debug_lines *lines)
free (lines->line_buf);
}
+static void
+destroy_cus (struct CU *cu)
+{
+ while (cu != NULL)
+ {
+ struct CU *next_cu = cu->next;
+ free (cu);
+ cu = next_cu;
+ }
+}
+
#define read_uleb128(ptr) ({ \
unsigned int ret = 0; \
unsigned int c; \
@@ -327,12 +354,6 @@ static uint32_t (*do_read_32) (unsigned char *ptr);
static void (*do_write_16) (unsigned char *ptr, uint16_t val);
static void (*do_write_32) (unsigned char *ptr, uint32_t val);
-static int ptr_size;
-static int cu_version;
-
-/* The offset into the .debug_str_offsets section for the current CU. */
-static uint32_t str_offsets_base;
-
static inline uint16_t
buf_read_ule16 (unsigned char *data)
{
@@ -751,7 +772,7 @@ do_read_uleb128 (unsigned char *ptr)
static inline uint32_t
do_read_str_form_relocated (DSO *dso, uint32_t form, unsigned char *ptr,
- struct debug_section *sec)
+ struct debug_section *sec, struct CU *cu)
{
uint32_t idx;
switch (form)
@@ -781,7 +802,7 @@ do_read_str_form_relocated (DSO *dso, uint32_t form, unsigned char *ptr,
}
unsigned char *str_off_ptr = debug_sections[DEBUG_STR_OFFSETS].data;
- str_off_ptr += str_offsets_base;
+ str_off_ptr += cu->str_offsets_base;
str_off_ptr += idx * 4;
struct debug_section *str_offsets_sec = &debug_sections[DEBUG_STR_OFFSETS];
@@ -1301,7 +1322,7 @@ destroy_strings (struct strings *strings)
outputs a warning if there was a problem reading the table at the
given offset. */
static bool
-get_line_table (DSO *dso, size_t off, struct line_table **table)
+get_line_table (DSO *dso, size_t off, struct line_table **table, struct CU *cu)
{
struct debug_lines *lines = &dso->lines;
/* Assume there aren't that many, just do a linear search. The
@@ -1336,6 +1357,7 @@ get_line_table (DSO *dso, size_t off, struct line_table **table)
struct line_table *t = &lines->table[lines->used];
*table = NULL;
+ t->cu = cu;
t->old_idx = off;
t->new_idx = off;
t->size_diff = 0;
@@ -1387,8 +1409,8 @@ get_line_table (DSO *dso, size_t off, struct line_table **table)
if (t->version >= 5)
{
/* address_size */
- assert (ptr_size != 0);
- if (ptr_size != read_8 (ptr))
+ assert (cu->ptr_size != 0);
+ if (cu->ptr_size != read_8 (ptr))
{
error (0, 0, "%s: .debug_line address size differs from .debug_info",
dso->filename);
@@ -1637,7 +1659,7 @@ edit_dwarf2_line (DSO *dso)
Also handles DW_FORM_strx, but just for recording the (indexed) string. */
static void
edit_strp (DSO *dso, uint32_t form, unsigned char *ptr, int phase,
- bool handled_strp, struct debug_section *sec)
+ bool handled_strp, struct debug_section *sec, struct CU *cu)
{
unsigned char *ptr_orig = ptr;
@@ -1651,7 +1673,7 @@ edit_strp (DSO *dso, uint32_t form, unsigned char *ptr, int phase,
recorded. */
if (! handled_strp)
{
- size_t idx = do_read_str_form_relocated (dso, form, ptr, sec);
+ size_t idx = do_read_str_form_relocated (dso, form, ptr, sec, cu);
record_existing_string_entry_idx (form == DW_FORM_line_strp,
dso, idx);
}
@@ -1676,15 +1698,15 @@ edit_strp (DSO *dso, uint32_t form, unsigned char *ptr, int phase,
/* Adjust *PTRP after the current *FORMP, update *FORMP for FORM_INDIRECT. */
static enum { FORM_OK, FORM_ERROR, FORM_INDIRECT }
-skip_form (DSO *dso, uint32_t *formp, unsigned char **ptrp)
+skip_form (DSO *dso, uint32_t *formp, unsigned char **ptrp, struct CU *cu)
{
size_t len = 0;
switch (*formp)
{
case DW_FORM_ref_addr:
- if (cu_version == 2)
- *ptrp += ptr_size;
+ if (cu->cu_version == 2)
+ *ptrp += cu->ptr_size;
else
*ptrp += 4;
break;
@@ -1692,7 +1714,7 @@ skip_form (DSO *dso, uint32_t *formp, unsigned char **ptrp)
case DW_FORM_implicit_const:
break;
case DW_FORM_addr:
- *ptrp += ptr_size;
+ *ptrp += cu->ptr_size;
break;
case DW_FORM_ref1:
case DW_FORM_flag:
@@ -2044,17 +2066,21 @@ read_dwarf5_line_entries (DSO *dso, unsigned char **ptrp,
switch (form)
{
- /* Note we don't expect DW_FORM_strx in the line table. */
case DW_FORM_strp:
case DW_FORM_line_strp:
+ case DW_FORM_strx:
+ case DW_FORM_strx1:
+ case DW_FORM_strx2:
+ case DW_FORM_strx3:
+ case DW_FORM_strx4:
edit_strp (dso, form, *ptrp, phase, handled_strp,
- &debug_sections[DEBUG_LINE]);
+ &debug_sections[DEBUG_LINE], table->cu);
break;
}
if (!handled_form)
{
- switch (skip_form (dso, &form, ptrp))
+ switch (skip_form (dso, &form, ptrp, table->cu))
{
case FORM_OK:
break;
@@ -2177,12 +2203,12 @@ read_dwarf5_line (DSO *dso, unsigned char *ptr, struct line_table *table,
adjustments needed in the debug_list data structures. Returns true
if line_table needs to be rewrite either the dir or file paths. */
static bool
-read_dwarf2_line (DSO *dso, uint32_t off, char *comp_dir)
+read_dwarf2_line (DSO *dso, uint32_t off, char *comp_dir, struct CU *cu)
{
unsigned char *ptr;
struct line_table *table;
- if (get_line_table (dso, off, &table) == false
+ if (get_line_table (dso, off, &table, cu) == false
|| table == NULL)
return false;
@@ -2232,10 +2258,10 @@ find_new_list_offs (struct debug_lines *lines, size_t idx)
static void
edit_attributes_str_comp_dir (uint32_t form, DSO *dso, unsigned char **ptrp,
int phase, char **comp_dirp, bool *handled_strpp,
- struct debug_section *debug_sec)
+ struct debug_section *debug_sec, struct CU *cu)
{
const char *dir;
- size_t idx = do_read_str_form_relocated (dso, form, *ptrp, debug_sec);
+ size_t idx = do_read_str_form_relocated (dso, form, *ptrp, debug_sec, cu);
bool line_strp = form == DW_FORM_line_strp;
/* In phase zero we collect the comp_dir. */
if (phase == 0)
@@ -2270,7 +2296,7 @@ edit_attributes_str_comp_dir (uint32_t form, DSO *dso, unsigned char **ptrp,
data might be replaced/updated. */
static unsigned char *
edit_attributes (DSO *dso, unsigned char *ptr, struct abbrev_tag *t, int phase,
- struct debug_section *debug_sec)
+ struct debug_section *debug_sec, struct CU *cu)
{
int i;
uint32_t list_offs;
@@ -2377,7 +2403,7 @@ edit_attributes (DSO *dso, unsigned char *ptr, struct abbrev_tag *t, int phase,
|| form == DW_FORM_strx4)
edit_attributes_str_comp_dir (form, dso,
&ptr, phase, &comp_dir,
- &handled_strp, debug_sec);
+ &handled_strp, debug_sec, cu);
}
else if ((t->tag == DW_TAG_compile_unit
|| t->tag == DW_TAG_partial_unit)
@@ -2400,7 +2426,7 @@ edit_attributes (DSO *dso, unsigned char *ptr, struct abbrev_tag *t, int phase,
Note that we don't handle DW_FORM_string in this
case. */
size_t idx = do_read_str_form_relocated (dso, form, ptr,
- debug_sec);
+ debug_sec, cu);
/* In phase zero we will look for a comp_dir to use. */
if (phase == 0)
@@ -2453,11 +2479,11 @@ edit_attributes (DSO *dso, unsigned char *ptr, struct abbrev_tag *t, int phase,
case DW_FORM_strx2:
case DW_FORM_strx3:
case DW_FORM_strx4:
- edit_strp (dso, form, ptr, phase, handled_strp, debug_sec);
+ edit_strp (dso, form, ptr, phase, handled_strp, debug_sec, cu);
break;
}
- switch (skip_form (dso, &form, &ptr))
+ switch (skip_form (dso, &form, &ptr, cu))
{
case FORM_OK:
break;
@@ -2511,7 +2537,7 @@ edit_attributes (DSO *dso, unsigned char *ptr, struct abbrev_tag *t, int phase,
separately (at the end of phase zero after all CUs have been
scanned in dwarf2_edit). */
if (phase == 0 && found_list_offs
- && read_dwarf2_line (dso, list_offs, comp_dir))
+ && read_dwarf2_line (dso, list_offs, comp_dir, cu))
need_stmt_update = true;
free (comp_dir);
@@ -2542,6 +2568,7 @@ edit_info (DSO *dso, int phase, struct debug_section *sec)
struct abbrev_tag tag, *t;
int i;
bool first;
+ struct CU *cu;
ptr = sec->data;
if (ptr == NULL)
@@ -2551,6 +2578,14 @@ edit_info (DSO *dso, int phase, struct debug_section *sec)
endsec = ptr + sec->size;
while (ptr < endsec)
{
+ cu = malloc (sizeof (struct CU));
+ if (cu == NULL)
+ error (1, errno, "%s: Could not allocate memory for next CU",
+ dso->filename);
+
+ cu->next = dso->cus;
+ dso->cus = cu;
+
unsigned char *cu_start = ptr;
/* header size, version, unit_type, ptr_size. */
@@ -2575,7 +2610,7 @@ edit_info (DSO *dso, int phase, struct debug_section *sec)
return 1;
}
- cu_version = read_16 (ptr);
+ int cu_version = read_16 (ptr);
if (cu_version != 2 && cu_version != 3 && cu_version != 4
&& cu_version != 5)
{
@@ -2583,6 +2618,7 @@ edit_info (DSO *dso, int phase, struct debug_section *sec)
cu_version);
return 1;
}
+ cu->cu_version = cu_version;
int cu_ptr_size = 0;
@@ -2620,23 +2656,15 @@ edit_info (DSO *dso, int phase, struct debug_section *sec)
if (cu_version < 5)
cu_ptr_size = read_8 (ptr);
- if (ptr_size == 0)
+ if (cu_ptr_size != 4 && cu_ptr_size != 8)
{
- ptr_size = cu_ptr_size;
- if (ptr_size != 4 && ptr_size != 8)
- {
- error (0, 0, "%s: Invalid DWARF pointer size %d",
- dso->filename, ptr_size);
- return 1;
- }
- }
- else if (cu_ptr_size != ptr_size)
- {
- error (0, 0, "%s: DWARF pointer size differs between CUs",
- dso->filename);
+ error (0, 0, "%s: Invalid DWARF pointer size %d",
+ dso->filename, cu_ptr_size);
return 1;
}
+ cu->ptr_size = cu_ptr_size;
+
if (sec != &debug_sections[DEBUG_INFO])
ptr += 12; /* Skip type_signature and type_offset. */
@@ -2646,7 +2674,6 @@ edit_info (DSO *dso, int phase, struct debug_section *sec)
return 1;
first = true;
- str_offsets_base = 0;
while (ptr < endcu)
{
tag.entry = read_uleb128 (ptr);
@@ -2674,14 +2701,15 @@ edit_info (DSO *dso, int phase, struct debug_section *sec)
form = t->attr[i].form;
if (t->attr[i].attr == DW_AT_str_offsets_base)
{
- str_offsets_base = do_read_32_relocated (fptr, sec);
+ cu->str_offsets_base = do_read_32_relocated (fptr,
+ sec);
break;
}
- skip_form (dso, &form, &fptr);
+ skip_form (dso, &form, &fptr, cu);
}
}
}
- ptr = edit_attributes (dso, ptr, t, phase, sec);
+ ptr = edit_attributes (dso, ptr, t, phase, sec, cu);
if (ptr == NULL)
break;
}
@@ -2764,7 +2792,6 @@ edit_dwarf2 (DSO *dso)
debug_sections[i].sec = 0;
debug_sections[i].relsec = 0;
}
- ptr_size = 0;
for (i = 1; i < dso->ehdr.e_shnum; ++i)
if (! (dso->shdr[i].sh_flags & (SHF_ALLOC | SHF_WRITE | SHF_EXECINSTR))
@@ -3346,6 +3373,7 @@ error_out:
destroy_strings (&dso->debug_str);
destroy_strings (&dso->debug_line_str);
destroy_lines (&dso->lines);
+ destroy_cus (dso->cus);
free (dso);
}
if (elf)
@@ -3847,6 +3875,7 @@ main (int argc, char *argv[])
destroy_strings (&dso->debug_str);
destroy_strings (&dso->debug_line_str);
destroy_lines (&dso->lines);
+ destroy_cus (dso->cus);
free (dso);
/* In case there were multiple (COMDAT) .debug_macro sections,
--
2.45.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 2/2] debugedit: Handle DW_MACRO_{define,undef}_strx
2024-05-19 21:05 [PATCH 1/2] debugedit: Track active CU Mark Wielaard
@ 2024-05-19 21:05 ` Mark Wielaard
2024-05-22 14:02 ` Mark Wielaard
2024-05-22 13:52 ` [PATCH 1/2] debugedit: Track active CU Mark Wielaard
1 sibling, 1 reply; 4+ messages in thread
From: Mark Wielaard @ 2024-05-19 21:05 UTC (permalink / raw)
To: debugedit; +Cc: Mark Wielaard
For DW_MACRO_{define,undef}_strx we need to record the string index of
the macro. Since this is read through the .debug_str_offets we need to
know the relevant str_offsets_base of the CU associated with the macro
table. Add a macros_offs field to struct CU. Set this in when seeing a
DW_AT_macros. And make sure relocations against .debug_macros are
resolved when handling ET_REL files.
Now all (macro) tests pass with CC=clang even when clang defaults to
-gdwarf-5. The .debug_types tests are skipped because clang doesn't
emit that section.
Signed-off-by: Mark Wielaard <mark@klomp.org>
---
tools/debugedit.c | 39 +++++++++++++++++++++++++++++++++++++--
1 file changed, 37 insertions(+), 2 deletions(-)
diff --git a/tools/debugedit.c b/tools/debugedit.c
index 6f93fb702876..6bdb3f7f1d63 100644
--- a/tools/debugedit.c
+++ b/tools/debugedit.c
@@ -199,6 +199,8 @@ struct CU
int cu_version;
/* The offset into the .debug_str_offsets section for this CU. */
uint32_t str_offsets_base;
+ /* The offset into the .debug_macros section for this CU (DW_AT_macros). */
+ uint32_t macros_offs;
struct CU *next;
};
@@ -615,13 +617,14 @@ setup_relbuf (DSO *dso, debug_section *sec)
if (dso->shdr[i].sh_type == SHT_REL && sym.st_value == 0)
continue;
/* Only consider relocations against .debug_str,
- .debug_str_offsets, .debug_line, .debug_line_str, and
- .debug_abbrev. */
+ .debug_str_offsets, .debug_line, .debug_line_str,
+ .debug_macro and .debug_abbrev. */
if (sym.st_shndx == 0 ||
(sym.st_shndx != debug_sections[DEBUG_STR].sec
&& sym.st_shndx != debug_sections[DEBUG_STR_OFFSETS].sec
&& sym.st_shndx != debug_sections[DEBUG_LINE].sec
&& sym.st_shndx != debug_sections[DEBUG_LINE_STR].sec
+ && sym.st_shndx != debug_sections[DEBUG_MACRO].sec
&& sym.st_shndx != debug_sections[DEBUG_ABBREV].sec))
continue;
rela.r_addend += sym.st_value;
@@ -2338,6 +2341,9 @@ edit_attributes (DSO *dso, unsigned char *ptr, struct abbrev_tag *t, int phase,
}
}
+ if (t->attr[i].attr == DW_AT_macros)
+ cu->macros_offs = do_read_32_relocated (ptr, debug_sec);
+
/* DW_AT_comp_dir is the current working directory. */
if (t->attr[i].attr == DW_AT_comp_dir)
{
@@ -2778,6 +2784,20 @@ update_str_offsets (DSO *dso)
}
}
+static struct CU *
+find_macro_cu (DSO *dso, uint32_t macros_offs)
+{
+ struct CU *cu = dso->cus;
+ while (cu != NULL)
+ {
+ if (cu->macros_offs == macros_offs)
+ return cu;
+ cu = cu->next;
+ }
+
+ return dso->cus; /* Not found, assume first CU. */
+}
+
static int
edit_dwarf2 (DSO *dso)
{
@@ -3073,11 +3093,13 @@ edit_dwarf2 (DSO *dso)
endsec = ptr + macro_sec->size;
int op = 0, macro_version, macro_flags;
int offset_len = 4, line_offset = 0;
+ struct CU *cu = NULL;
while (ptr < endsec)
{
if (!op)
{
+ cu = find_macro_cu (dso, ptr - macro_sec->data);
macro_version = read_16 (ptr);
macro_flags = read_8 (ptr);
if (macro_version < 4 || macro_version > 5)
@@ -3149,6 +3171,19 @@ edit_dwarf2 (DSO *dso)
case DW_MACRO_GNU_transparent_include:
ptr += offset_len;
break;
+ case DW_MACRO_define_strx:
+ case DW_MACRO_undef_strx:
+ read_uleb128 (ptr);
+ if (phase == 0)
+ {
+ size_t idx;
+ idx = do_read_str_form_relocated (dso, DW_FORM_strx,
+ ptr, macro_sec,
+ cu);
+ record_existing_string_entry_idx (false, dso, idx);
+ }
+ read_uleb128 (ptr);
+ break;
default:
error (1, 0, "Unhandled DW_MACRO op 0x%x", op);
break;
--
2.45.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 1/2] debugedit: Track active CU
2024-05-19 21:05 [PATCH 1/2] debugedit: Track active CU Mark Wielaard
2024-05-19 21:05 ` [PATCH 2/2] debugedit: Handle DW_MACRO_{define,undef}_strx Mark Wielaard
@ 2024-05-22 13:52 ` Mark Wielaard
1 sibling, 0 replies; 4+ messages in thread
From: Mark Wielaard @ 2024-05-22 13:52 UTC (permalink / raw)
To: debugedit
Hi,
On Sun, 2024-05-19 at 23:05 +0200, Mark Wielaard wrote:
> The current CU is tracked indirectly by having static variables for
> ptr_size, cu_version and str_offsets_base. These are used to
> process/skip forms and resolve strx forms. Put all three in a new
> struct CU which must be passed to do_read_str_form_relocated,
> skip_form, edit_strp and edit_attributes. The struct CU can then also
> be used when parsing the line table string forms.
>
> This should make .debug_line tables which use strx forms work (no
> producers have been found that use those though).
Pushed to main.
Cheers,
Mark
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 2/2] debugedit: Handle DW_MACRO_{define,undef}_strx
2024-05-19 21:05 ` [PATCH 2/2] debugedit: Handle DW_MACRO_{define,undef}_strx Mark Wielaard
@ 2024-05-22 14:02 ` Mark Wielaard
0 siblings, 0 replies; 4+ messages in thread
From: Mark Wielaard @ 2024-05-22 14:02 UTC (permalink / raw)
To: debugedit
Hi,
On Sun, 2024-05-19 at 23:05 +0200, Mark Wielaard wrote:
> For DW_MACRO_{define,undef}_strx we need to record the string index of
> the macro. Since this is read through the .debug_str_offets we need to
> know the relevant str_offsets_base of the CU associated with the macro
> table. Add a macros_offs field to struct CU. Set this in when seeing a
> DW_AT_macros. And make sure relocations against .debug_macros are
> resolved when handling ET_REL files.
>
> Now all (macro) tests pass with CC=clang even when clang defaults to
> -gdwarf-5. The .debug_types tests are skipped because clang doesn't
> emit that section.
Pushed to main. Hopefully all builders will now be green!
Cheers,
Mark
^ permalink raw reply [flat|nested] 4+ messages in thread
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Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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