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c5ff46d69c
In a few places we want to calculate the address of the next instruction. Previously that was simple, we just added 4 bytes, or if using a u32 * we incremented that pointer by 1. But prefixed instructions make it more complicated, we need to advance by either 4 or 8 bytes depending on the actual instruction. We also can't do pointer arithmetic using struct ppc_inst, because it is always 8 bytes in size on 64-bit, even though we might only need to advance by 4 bytes. So add a ppc_inst_next() helper which calculates the location of the next instruction, if the given instruction was located at the given address. Note the instruction doesn't need to actually be at the address in memory. Although it would seem natural for the value to be passed by value, that makes it too easy to write a loop that will read off the end of a page, eg: for (; src < end; src = ppc_inst_next(src, *src), dest = ppc_inst_next(dest, *dest)) As noticed by Christophe and Jordan, if end is the exact end of a page, and the next page is not mapped, this will fault, because *dest will read 8 bytes, 4 bytes into the next page. So value is passed by reference, so the helper can be careful to use ppc_inst_read() on it. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Jordan Niethe <jniethe5@gmail.com> Link: https://lore.kernel.org/r/20200522133318.1681406-1-mpe@ellerman.id.au |
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| .. | ||
| ansidecl.h | ||
| dis-asm.h | ||
| Makefile | ||
| nonstdio.c | ||
| nonstdio.h | ||
| ppc-dis.c | ||
| ppc-opc.c | ||
| ppc.h | ||
| spr_access.S | ||
| spu-dis.c | ||
| spu-insns.h | ||
| spu-opc.c | ||
| spu.h | ||
| xmon.c | ||
| xmon_bpts.h | ||
| xmon_bpts.S | ||