Messages in this thread Patch in this message | | | Date | Thu, 26 May 2005 19:02:11 -0500 (CDT) | From | Kumar Gala <> | Subject | [PATCH] ppc32: Simplified load string emulation error checking |
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The error checking for emulation of load string instructions was overly generous and would cause certain valid forms of the instructions to be treated as illegal. We drop the range checking since the architecture allows this to be boundedly undefined. Tests on CPUs that support these instructions appear not do cause illegal instruction traps on range errors and just allow the execution to occur.
Thanks to Kim Phillips for debugging this and figuring out what real HW was doing.
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
--- commit 219d058f65dbd666964b1e951b8d491e4b19dc0c tree 109a4648d2cc627d17c129bc1ca102a736c817aa parent 4b1b1ed3400c905819fc4668838dbec4099f2d8d author Kumar K. Gala <kumar.gala@freescale.com> Thu, 26 May 2005 18:55:56 -0500 committer Kumar K. Gala <kumar.gala@freescale.com> Thu, 26 May 2005 18:55:56 -0500
ppc/kernel/traps.c | 7 +------ 1 files changed, 1 insertion(+), 6 deletions(-)
Index: arch/ppc/kernel/traps.c =================================================================== --- 94fc6c9507563e89a75b0838824003b2301b4321/arch/ppc/kernel/traps.c (mode:100644) +++ 109a4648d2cc627d17c129bc1ca102a736c817aa/arch/ppc/kernel/traps.c (mode:100644) @@ -408,12 +408,7 @@ /* Early out if we are an invalid form of lswx */ if ((instword & INST_STRING_MASK) == INST_LSWX) - if ((rA >= rT) || (NB_RB >= rT) || (rT == rA) || (rT == NB_RB)) - return -EINVAL; - - /* Early out if we are an invalid form of lswi */ - if ((instword & INST_STRING_MASK) == INST_LSWI) - if ((rA >= rT) || (rT == rA)) + if ((rT == rA) || (rT == NB_RB)) return -EINVAL; EA = (rA == 0) ? 0 : regs->gpr[rA]; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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