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asm-generic: Define CONFIG_HAVE_FUNCTION_DESCRIPTORS

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Replace HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR by a config option
named CONFIG_HAVE_FUNCTION_DESCRIPTORS and use it instead of
'dereference_function_descriptor' macro to know whether an
arch has function descriptors.

To limit churn in one of the following patches, use
an #ifdef/#else construct with empty first part
instead of an #ifndef in asm-generic/sections.h

On powerpc, make sure the config option matches the ABI used
by the compiler with a BUILD_BUG_ON() and add missing _CALL_ELF=2
when calling 'sparse' so that sparse sees the same piece of
code as GCC.

And include a helper to check whether an arch has function
descriptors or not : have_function_descriptors()

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4a0f11fb0ea74a3197bc44dd7ba25e53a24fd03d.1644928018.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2022-02-15 13:41:02 +01:00 committed by Michael Ellerman
parent 41a88b4547
commit a257cacc38
10 changed files with 20 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
arch/Kconfig
View File

@ -205,6 +205,9 @@ config HAVE_FUNCTION_ERROR_INJECTION
config HAVE_NMI
bool
config HAVE_FUNCTION_DESCRIPTORS
bool
config TRACE_IRQFLAGS_SUPPORT
bool

1
arch/ia64/Kconfig
View File

@ -35,6 +35,7 @@ config IA64
select HAVE_SETUP_PER_CPU_AREA
select TTY
select HAVE_ARCH_TRACEHOOK
select HAVE_FUNCTION_DESCRIPTORS
select HAVE_VIRT_CPU_ACCOUNTING
select HUGETLB_PAGE_SIZE_VARIABLE if HUGETLB_PAGE
select VIRT_TO_BUS

2
arch/ia64/include/asm/sections.h
View File

@ -27,8 +27,6 @@ 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[];
#define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1
#undef dereference_function_descriptor
static inline void *dereference_function_descriptor(void *ptr)
{

1
arch/parisc/Kconfig
View File

@ -69,6 +69,7 @@ config PARISC
select HAVE_DYNAMIC_FTRACE_WITH_REGS
select HAVE_SOFTIRQ_ON_OWN_STACK if IRQSTACKS
select TRACE_IRQFLAGS_SUPPORT
select HAVE_FUNCTION_DESCRIPTORS if 64BIT
help
The PA-RISC microprocessor is designed by Hewlett-Packard and used

2
arch/parisc/include/asm/sections.h
View File

@ -9,8 +9,6 @@ extern char __alt_instructions[], __alt_instructions_end[];
#ifdef CONFIG_64BIT
#define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1
#undef dereference_function_descriptor
void *dereference_function_descriptor(void *);

1
arch/powerpc/Kconfig
View File

@ -202,6 +202,7 @@ config PPC
select HAVE_EFFICIENT_UNALIGNED_ACCESS if !(CPU_LITTLE_ENDIAN && POWER7_CPU)
select HAVE_FAST_GUP
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_DESCRIPTORS if PPC64 && !CPU_LITTLE_ENDIAN
select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER

2
arch/powerpc/include/asm/sections.h
View File

@ -56,8 +56,6 @@ static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
#ifdef PPC64_ELF_ABI_v1
#define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1
#undef dereference_function_descriptor
static inline void *dereference_function_descriptor(void *ptr)
{

6
arch/powerpc/kernel/ptrace/ptrace.c
View File

@ -445,4 +445,10 @@ void __init pt_regs_check(void)
* real registers.
*/
BUILD_BUG_ON(PT_DSCR < sizeof(struct user_pt_regs) / sizeof(unsigned long));
#ifdef PPC64_ELF_ABI_v1
BUILD_BUG_ON(!IS_ENABLED(CONFIG_HAVE_FUNCTION_DESCRIPTORS));
#else
BUILD_BUG_ON(IS_ENABLED(CONFIG_HAVE_FUNCTION_DESCRIPTORS));
#endif
}

8
include/asm-generic/sections.h
View File

@ -59,11 +59,17 @@ extern char __noinstr_text_start[], __noinstr_text_end[];
extern __visible const void __nosave_begin, __nosave_end;
/* Function descriptor handling (if any). Override in asm/sections.h */
#ifndef dereference_function_descriptor
#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS
#else
#define dereference_function_descriptor(p) ((void *)(p))
#define dereference_kernel_function_descriptor(p) ((void *)(p))
#endif
static inline bool have_function_descriptors(void)
{
return IS_ENABLED(CONFIG_HAVE_FUNCTION_DESCRIPTORS);
}
/**
* memory_contains - checks if an object is contained within a memory region
* @begin: virtual address of the beginning of the memory region

2
include/linux/kallsyms.h
View File

@ -48,7 +48,7 @@ static inline int is_ksym_addr(unsigned long addr)
static inline void *dereference_symbol_descriptor(void *ptr)
{
#ifdef HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR
#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS
struct module *mod;
ptr = dereference_kernel_function_descriptor(ptr);