[PATCH 09/14] scripts/sorttable: Add helper functions for Elf_Ehdr

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_Ehdr. 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_Ehdr 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 | 25 +++++++++++++++++++++++++
scripts/sorttable.h | 20 ++++++++++++++++----
2 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/scripts/sorttable.c b/scripts/sorttable.c
index 57792cf2aa89..5dfa734eff09 100644
--- a/scripts/sorttable.c
+++ b/scripts/sorttable.c
@@ -85,6 +85,31 @@ static uint64_t (*r8)(const uint64_t *);
static void (*w)(uint32_t, uint32_t *);
typedef void (*table_sort_t)(char *, int);

+static uint64_t ehdr64_shoff(Elf_Ehdr *ehdr)
+{
+ return r8(&ehdr->e64.e_shoff);
+}
+
+static uint64_t ehdr32_shoff(Elf_Ehdr *ehdr)
+{
+ return r(&ehdr->e32.e_shoff);
+}
+
+#define EHDR_HALF(fn_name) \
+static uint16_t ehdr64_##fn_name(Elf_Ehdr *ehdr) \
+{ \
+ return r2(&ehdr->e64.e_##fn_name); \
+} \
+ \
+static uint16_t ehdr32_##fn_name(Elf_Ehdr *ehdr) \
+{ \
+ return r2(&ehdr->e32.e_##fn_name); \
+}
+
+EHDR_HALF(shentsize)
+EHDR_HALF(shstrndx)
+EHDR_HALF(shnum)
+
/*
* 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 a365a8bc405a..3855f2ad0e73 100644
--- a/scripts/sorttable.h
+++ b/scripts/sorttable.h
@@ -27,6 +27,10 @@
#undef uint_t
#undef _r
#undef etype
+#undef ehdr_shoff
+#undef ehdr_shentsize
+#undef ehdr_shstrndx
+#undef ehdr_shnum

#ifdef SORTTABLE_64
# define extable_ent_size 16
@@ -39,6 +43,10 @@
# define uint_t uint64_t
# define _r r8
# define etype e64
+# define ehdr_shoff ehdr64_shoff
+# define ehdr_shentsize ehdr64_shentsize
+# define ehdr_shstrndx ehdr64_shstrndx
+# define ehdr_shnum ehdr64_shnum
#else
# define extable_ent_size 8
# define compare_extable compare_extable_32
@@ -50,6 +58,10 @@
# define uint_t uint32_t
# define _r r
# define etype e32
+# define ehdr_shoff ehdr32_shoff
+# define ehdr_shentsize ehdr32_shentsize
+# define ehdr_shstrndx ehdr32_shstrndx
+# define ehdr_shnum ehdr32_shnum
#endif

#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
@@ -247,16 +259,16 @@ static int do_sort(Elf_Ehdr *ehdr,
unsigned int orc_num_entries = 0;
#endif

- shdr_start = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->etype.e_shoff));
- shentsize = r2(&ehdr->etype.e_shentsize);
+ shdr_start = (Elf_Shdr *)((char *)ehdr + ehdr_shoff(ehdr));
+ shentsize = ehdr_shentsize(ehdr);

- shstrndx = r2(&ehdr->etype.e_shstrndx);
+ shstrndx = ehdr_shstrndx(ehdr);
if (shstrndx == SHN_XINDEX)
shstrndx = r(&shdr_start->etype.sh_link);
string_sec = get_index(shdr_start, shentsize, shstrndx);
secstrings = (const char *)ehdr + _r(&string_sec->etype.sh_offset);

- shnum = r2(&ehdr->etype.e_shnum);
+ shnum = ehdr_shnum(ehdr);
if (shnum == SHN_UNDEF)
shnum = _r(&shdr_start->etype.sh_size);

--
2.45.2