[PATCH v1 06/10] asm-generic: Refactor dereference_[kernel]_function_descriptor()

Christophe Leroy
2021-10-11T15:25:33Z

dereference_function_descriptor() and
dereference_kernel_function_descriptor() are identical on the
three architectures implementing them.

Make it common.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/ia64/include/asm/sections.h | 19 -------------------
arch/parisc/include/asm/sections.h | 9 ---------
arch/parisc/kernel/process.c | 21 ---------------------
arch/powerpc/include/asm/sections.h | 23 -----------------------
include/asm-generic/sections.h | 18 ++++++++++++++++++
5 files changed, 18 insertions(+), 72 deletions(-)

diff --git a/arch/ia64/include/asm/sections.h b/arch/ia64/include/asm/sections.h
index 929b5c535620..d9addaea8339 100644
--- a/arch/ia64/include/asm/sections.h
+++ b/arch/ia64/include/asm/sections.h
@@ -30,23 +30,4 @@ extern char __start_gate_brl_fsys_bubble_down_patchlist[], __end_gate_brl_fsys_b
extern char __start_unwind[], __end_unwind[];
extern char __start_ivt_text[], __end_ivt_text[];

-#undef dereference_function_descriptor
-static inline void *dereference_function_descriptor(void *ptr)
-{
- struct fdesc *desc = ptr;
- void *p;
-
- if (!get_kernel_nofault(p, (void *)&desc->addr))
- ptr = p;
- return ptr;
-}
-
-#undef dereference_kernel_function_descriptor
-static inline void *dereference_kernel_function_descriptor(void *ptr)
-{
- if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd)
- return ptr;
- return dereference_function_descriptor(ptr);
-}
-
#endif /* _ASM_IA64_SECTIONS_H */
diff --git a/arch/parisc/include/asm/sections.h b/arch/parisc/include/asm/sections.h
index 329e80f7af0a..b041fb32a300 100644
--- a/arch/parisc/include/asm/sections.h
+++ b/arch/parisc/include/asm/sections.h
@@ -12,13 +12,4 @@ typedef Elf64_Fdesc funct_descr_t;

extern char __alt_instructions[], __alt_instructions_end[];

-#ifdef CONFIG_64BIT
-
-#undef dereference_function_descriptor
-void *dereference_function_descriptor(void *);
-
-#undef dereference_kernel_function_descriptor
-void *dereference_kernel_function_descriptor(void *);
-#endif
-
#endif
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index 38ec4ae81239..7382576b52a8 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -266,27 +266,6 @@ get_wchan(struct task_struct *p)
return 0;
}

-#ifdef CONFIG_64BIT
-void *dereference_function_descriptor(void *ptr)
-{
- Elf64_Fdesc *desc = ptr;
- void *p;
-
- if (!get_kernel_nofault(p, (void *)&desc->addr))
- ptr = p;
- return ptr;
-}
-
-void *dereference_kernel_function_descriptor(void *ptr)
-{
- if (ptr < (void *)__start_opd ||
- ptr >= (void *)__end_opd)
- return ptr;
-
- return dereference_function_descriptor(ptr);
-}
-#endif
-
static inline unsigned long brk_rnd(void)
{
return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index d0d5287fa568..8f8e95f234e2 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -72,29 +72,6 @@ static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
(unsigned long)_stext < end;
}

-#ifdef PPC64_ELF_ABI_v1
-
-#undef dereference_function_descriptor
-static inline void *dereference_function_descriptor(void *ptr)
-{
- struct ppc64_opd_entry *desc = ptr;
- void *p;
-
- if (!get_kernel_nofault(p, (void *)&desc->addr))
- ptr = p;
- return ptr;
-}
-
-#undef dereference_kernel_function_descriptor
-static inline void *dereference_kernel_function_descriptor(void *ptr)
-{
- if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd)
- return ptr;
-
- return dereference_function_descriptor(ptr);
-}
-#endif /* PPC64_ELF_ABI_v1 */
-
#endif

#endif /* __KERNEL__ */
diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index 436412d94054..5baaf9d7c671 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -60,6 +60,24 @@ extern __visible const void __nosave_begin, __nosave_end;

/* Function descriptor handling (if any). Override in asm/sections.h */
#ifdef HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR
+static inline void *dereference_function_descriptor(void *ptr)
+{
+ funct_descr_t *desc = ptr;
+ void *p;
+
+ if (!get_kernel_nofault(p, (void *)&desc->addr))
+ ptr = p;
+ return ptr;
+}
+
+static inline void *dereference_kernel_function_descriptor(void *ptr)
+{
+ if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd)
+ return ptr;
+
+ return dereference_function_descriptor(ptr);
+}
+
#else
#define dereference_function_descriptor(p) ((void *)(p))
#define dereference_kernel_function_descriptor(p) ((void *)(p))
--
2.31.1