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powerpc/kernel: Use kprobe blacklist for asm functions 

Rather than forcing the whole function into the ".kprobes.text" section,
just add the symbol's address to the kprobe blacklist.

This also lets us drop the three versions of the_KPROBE macro, in
exchange for just one version of _ASM_NOKPROBE_SYMBOL - which is a good
cleanup.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Nicholas Piggin 2016-09-16 20:48:17 +10:00 committed by Michael Ellerman
parent 03465f899b
commit 6f698df10c
3 changed files with 20 additions and 29 deletions
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40
arch/powerpc/include/asm/ppc_asm.h
View File

@ -217,13 +217,6 @@ name: \
addi r2,r2,(.TOC.-0b)@l; \
.localentry name,.-name
#define _KPROBE(name) \
.section ".kprobes.text","a"; \
.align 2 ; \
.type name,@function; \
.globl name; \
name:
#define DOTSYM(a) a
#else
@ -247,20 +240,6 @@ GLUE(.,name):
#define _GLOBAL_TOC(name) _GLOBAL(name)
#define _KPROBE(name) \
.section ".kprobes.text","a"; \
.align 2 ; \
.globl name; \
.globl GLUE(.,name); \
.section ".opd","aw"; \
name: \
.quad GLUE(.,name); \
.quad .TOC.@tocbase; \
.quad 0; \
.previous; \
.type GLUE(.,name),@function; \
GLUE(.,name):
#define DOTSYM(a) GLUE(.,a)
#endif
@ -279,13 +258,22 @@ GLUE(.,name):
#define _GLOBAL_TOC(name) _GLOBAL(name)
#define _KPROBE(n) \
.section ".kprobes.text","a"; \
.globl n; \
n:
#endif
/*
* __kprobes (the C annotation) puts the symbol into the .kprobes.text
* section, which gets emitted at the end of regular text.
*
* _ASM_NOKPROBE_SYMBOL and NOKPROBE_SYMBOL just adds the symbol to
* a blacklist. The former is for core kprobe functions/data, the
* latter is for those that incdentially must be excluded from probing
* and allows them to be linked at more optimal location within text.
*/
#define _ASM_NOKPROBE_SYMBOL(entry) \
.pushsection "_kprobe_blacklist","aw"; \
PPC_LONG (entry) ; \
.popsection
#define FUNC_START(name) _GLOBAL(name)
#define FUNC_END(name)

4
arch/powerpc/kernel/misc_32.S
View File

@ -328,7 +328,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_UNIFIED_ID_CACHE)
*
* flush_icache_range(unsigned long start, unsigned long stop)
*/
_KPROBE(flush_icache_range)
_GLOBAL(flush_icache_range)
BEGIN_FTR_SECTION
PURGE_PREFETCHED_INS
blr /* for 601, do nothing */
@ -358,6 +358,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
sync /* additional sync needed on g4 */
isync
blr
_ASM_NOKPROBE_SYMBOL(flush_icache_range)
/*
* Flush a particular page from the data cache to RAM.
* Note: this is necessary because the instruction cache does *not*

5
arch/powerpc/kernel/misc_64.S
View File

@ -66,7 +66,7 @@ PPC64_CACHES:
* flush all bytes from start through stop-1 inclusive
*/
_KPROBE(flush_icache_range)
_GLOBAL(flush_icache_range)
BEGIN_FTR_SECTION
PURGE_PREFETCHED_INS
blr
@ -109,7 +109,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
bdnz 2b
isync
blr
.previous .text
_ASM_NOKPROBE_SYMBOL(flush_icache_range)
/*
* Like above, but only do the D-cache.
*