The ptrace POKETEXT interface allows a process to modify the text pages of
a child process being ptraced, usually to insert breakpoints via trap
instructions. The kernel eventually calls copy_to_user_page, which in turn
calls __flush_icache_range to invalidate the icache lines for the child
process.
However, this function does not work on 44x due to the icache being virtually
indexed. This was noticed by a breakpoint being triggered after it had been
cleared by ltrace on a 440EPx board. The convenient solution is to do a
flash invalidate of the icache in the __flush_icache_range function.
Signed-off-by: Josh Boyer <jwbo...@linux.vnet.ibm.com>
---
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 15f28e0..c9805a4 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -346,6 +346,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
2: icbi 0,r6
addi r6,r6,L1_CACHE_BYTES
bdnz 2b
+#ifdef CONFIG_44x
+ iccci r0, r0
+#endif
sync /* additional sync needed on g4 */
isync
blr
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