On Mon, 2009-08-17 at 09:41 -0400, Josh Boyer wrote: > 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>
I've put it in -test for now, but I'd like you to respin when you get a chance with: - removing the icbi loop in the 440 case - adding a nice fat comment explaining why next to the iccci instruction itself so we don't be tempted to remove it. Cheers, Ben. > --- > > 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 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
