[PATCH 10/14] scripts/sorttable: Add helper functions for Elf_Shdr

Steven Rostedt
2025-01-02T18:59:48Z

From: Steven Rostedt <rostedt@goodmis.org>

In order to remove the double #include of sorttable.h for 64 and 32 bit
to create duplicate functions, add helper functions for Elf_Shdr. This
will create a function pointer for each helper that will get assigned to
the appropriate function to handle either the 64bit or 32bit version.

This also moves the _r()/r() wrappers for the Elf_Shdr references that
handle endian and size differences between the different architectures,
into the helper function and out of the open code which is more error
prone.

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
scripts/sorttable.c | 42 +++++++++++++++++++++++++++++
scripts/sorttable.h | 66 +++++++++++++++++++++++++++++----------------
2 files changed, 85 insertions(+), 23 deletions(-)

diff --git a/scripts/sorttable.c b/scripts/sorttable.c
index 5dfa734eff09..b2b96ff261d6 100644
--- a/scripts/sorttable.c
+++ b/scripts/sorttable.c
@@ -110,6 +110,48 @@ EHDR_HALF(shentsize)
EHDR_HALF(shstrndx)
EHDR_HALF(shnum)

+#define SHDR_WORD(fn_name) \
+static uint32_t shdr64_##fn_name(Elf_Shdr *shdr) \
+{ \
+ return r(&shdr->e64.sh_##fn_name); \
+} \
+ \
+static uint32_t shdr32_##fn_name(Elf_Shdr *shdr) \
+{ \
+ return r(&shdr->e32.sh_##fn_name); \
+}
+
+#define SHDR_ADDR(fn_name) \
+static uint64_t shdr64_##fn_name(Elf_Shdr *shdr) \
+{ \
+ return r8(&shdr->e64.sh_##fn_name); \
+} \
+ \
+static uint64_t shdr32_##fn_name(Elf_Shdr *shdr) \
+{ \
+ return r(&shdr->e32.sh_##fn_name); \
+}
+
+#define SHDR_WORD(fn_name) \
+static uint32_t shdr64_##fn_name(Elf_Shdr *shdr) \
+{ \
+ return r(&shdr->e64.sh_##fn_name); \
+} \
+ \
+static uint32_t shdr32_##fn_name(Elf_Shdr *shdr) \
+{ \
+ return r(&shdr->e32.sh_##fn_name); \
+}
+
+SHDR_ADDR(addr)
+SHDR_ADDR(offset)
+SHDR_ADDR(size)
+SHDR_ADDR(entsize)
+
+SHDR_WORD(link)
+SHDR_WORD(name)
+SHDR_WORD(type)
+
/*
* Get the whole file as a programming convenience in order to avoid
* malloc+lseek+read+free of many pieces. If successful, then mmap
diff --git a/scripts/sorttable.h b/scripts/sorttable.h
index 3855f2ad0e73..a391757aaff0 100644
--- a/scripts/sorttable.h
+++ b/scripts/sorttable.h
@@ -31,6 +31,13 @@
#undef ehdr_shentsize
#undef ehdr_shstrndx
#undef ehdr_shnum
+#undef shdr_addr
+#undef shdr_offset
+#undef shdr_link
+#undef shdr_size
+#undef shdr_name
+#undef shdr_type
+#undef shdr_entsize

#ifdef SORTTABLE_64
# define extable_ent_size 16
@@ -47,6 +54,13 @@
# define ehdr_shentsize ehdr64_shentsize
# define ehdr_shstrndx ehdr64_shstrndx
# define ehdr_shnum ehdr64_shnum
+# define shdr_addr shdr64_addr
+# define shdr_offset shdr64_offset
+# define shdr_link shdr64_link
+# define shdr_size shdr64_size
+# define shdr_name shdr64_name
+# define shdr_type shdr64_type
+# define shdr_entsize shdr64_entsize
#else
# define extable_ent_size 8
# define compare_extable compare_extable_32
@@ -62,6 +76,13 @@
# define ehdr_shentsize ehdr32_shentsize
# define ehdr_shstrndx ehdr32_shstrndx
# define ehdr_shnum ehdr32_shnum
+# define shdr_addr shdr32_addr
+# define shdr_offset shdr32_offset
+# define shdr_link shdr32_link
+# define shdr_size shdr32_size
+# define shdr_name shdr32_name
+# define shdr_type shdr32_type
+# define shdr_entsize shdr32_entsize
#endif

#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
@@ -174,8 +195,8 @@ struct elf_mcount_loc {
static void *sort_mcount_loc(void *arg)
{
struct elf_mcount_loc *emloc = (struct elf_mcount_loc *)arg;
- uint_t offset = emloc->start_mcount_loc - _r(&(emloc->init_data_sec)->etype.sh_addr)
- + _r(&(emloc->init_data_sec)->etype.sh_offset);
+ uint_t offset = emloc->start_mcount_loc - shdr_addr(emloc->init_data_sec)
+ + shdr_offset(emloc->init_data_sec);
uint_t count = emloc->stop_mcount_loc - emloc->start_mcount_loc;
unsigned char *start_loc = (void *)emloc->ehdr + offset;

@@ -264,18 +285,18 @@ static int do_sort(Elf_Ehdr *ehdr,

shstrndx = ehdr_shstrndx(ehdr);
if (shstrndx == SHN_XINDEX)
- shstrndx = r(&shdr_start->etype.sh_link);
+ shstrndx = shdr_link(shdr_start);
string_sec = get_index(shdr_start, shentsize, shstrndx);
- secstrings = (const char *)ehdr + _r(&string_sec->etype.sh_offset);
+ secstrings = (const char *)ehdr + shdr_offset(string_sec);

shnum = ehdr_shnum(ehdr);
if (shnum == SHN_UNDEF)
- shnum = _r(&shdr_start->etype.sh_size);
+ shnum = shdr_size(shdr_start);

for (i = 0; i < shnum; i++) {
Elf_Shdr *shdr = get_index(shdr_start, shentsize, i);

- idx = r(&shdr->etype.sh_name);
+ idx = shdr_name(shdr);
if (!strcmp(secstrings + idx, "__ex_table"))
extab_sec = shdr;
if (!strcmp(secstrings + idx, ".symtab"))
@@ -283,9 +304,9 @@ static int do_sort(Elf_Ehdr *ehdr,
if (!strcmp(secstrings + idx, ".strtab"))
strtab_sec = shdr;

- if (r(&shdr->etype.sh_type) == SHT_SYMTAB_SHNDX)
+ if (shdr_type(shdr) == SHT_SYMTAB_SHNDX)
symtab_shndx = (Elf32_Word *)((const char *)ehdr +
- _r(&shdr->etype.sh_offset));
+ shdr_offset(shdr));

#ifdef MCOUNT_SORT_ENABLED
/* locate the .init.data section in vmlinux */
@@ -301,14 +322,14 @@ static int do_sort(Elf_Ehdr *ehdr,
#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
/* locate the ORC unwind tables */
if (!strcmp(secstrings + idx, ".orc_unwind_ip")) {
- orc_ip_size = _r(&shdr->etype.sh_size);
+ orc_ip_size = shdr_size(shdr);
g_orc_ip_table = (int *)((void *)ehdr +
- _r(&shdr->etype.sh_offset));
+ shdr_offset(shdr));
}
if (!strcmp(secstrings + idx, ".orc_unwind")) {
- orc_size = _r(&shdr->etype.sh_size);
+ orc_size = shdr_size(shdr);
g_orc_table = (struct orc_entry *)((void *)ehdr +
- _r(&shdr->etype.sh_offset));
+ shdr_offset(shdr));
}
#endif
} /* for loop */
@@ -371,23 +392,22 @@ static int do_sort(Elf_Ehdr *ehdr,
goto out;
}

- extab_image = (void *)ehdr + _r(&extab_sec->etype.sh_offset);
- strtab = (const char *)ehdr + _r(&strtab_sec->etype.sh_offset);
- symtab = (const Elf_Sym *)((const char *)ehdr +
- _r(&symtab_sec->etype.sh_offset));
+ extab_image = (void *)ehdr + shdr_offset(extab_sec);
+ strtab = (const char *)ehdr + shdr_offset(strtab_sec);
+ symtab = (const Elf_Sym *)((const char *)ehdr + shdr_offset(symtab_sec));

if (custom_sort) {
- custom_sort(extab_image, _r(&extab_sec->etype.sh_size));
+ custom_sort(extab_image, shdr_size(extab_sec));
} else {
- int num_entries = _r(&extab_sec->etype.sh_size) / extable_ent_size;
+ int num_entries = shdr_size(extab_sec) / extable_ent_size;
qsort(extab_image, num_entries,
extable_ent_size, compare_extable);
}

/* find the flag main_extable_sort_needed */
- sym_start = (void *)ehdr + _r(&symtab_sec->etype.sh_offset);
- sym_end = sym_start + _r(&symtab_sec->etype.sh_size);
- symentsize = _r(&symtab_sec->etype.sh_entsize);
+ sym_start = (void *)ehdr + shdr_offset(symtab_sec);
+ sym_end = sym_start + shdr_size(symtab_sec);
+ symentsize = shdr_entsize(symtab_sec);

for (sym = sym_start; (void *)sym + symentsize < sym_end;
sym = (void *)sym + symentsize) {
@@ -412,9 +432,9 @@ static int do_sort(Elf_Ehdr *ehdr,
symtab_shndx);
sort_needed_sec = get_index(shdr_start, shentsize, sort_need_index);
sort_needed_loc = (void *)ehdr +
- _r(&sort_needed_sec->etype.sh_offset) +
+ shdr_offset(sort_needed_sec) +
_r(&sort_needed_sym->etype.st_value) -
- _r(&sort_needed_sec->etype.sh_addr);
+ shdr_addr(sort_needed_sec);

/* extable has been sorted, clear the flag */
w(0, sort_needed_loc);
--
2.45.2