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authorAnanth N Mavinakayanahalli <ananth@linux.ibm.com>2021-01-25 14:06:43 +0100
committerMichael Ellerman <mpe@ellerman.id.au>2021-01-30 01:40:04 +0100
commit718aae916fa6619c57c348beaedd675835cf1aa1 (patch)
tree60a77b05c95e0163382e4f6ac99902156122c1cd /arch/powerpc/lib/sstep.c
parentpowerpc/sstep: Check instruction validity against ISA version before emulation (diff)
downloadlinux-718aae916fa6619c57c348beaedd675835cf1aa1.tar.xz
linux-718aae916fa6619c57c348beaedd675835cf1aa1.zip
powerpc/sstep: Fix incorrect return from analyze_instr()
We currently just percolate the return value from analyze_instr() to the caller of emulate_step(), especially if it is a -1. For one particular case (opcode = 4) for instructions that aren't currently emulated, we are returning 'should not be single-stepped' while we should have returned 0 which says 'did not emulate, may have to single-step'. Fixes: 930d6288a26787 ("powerpc: sstep: Add support for maddhd, maddhdu, maddld instructions") Signed-off-by: Ananth N Mavinakayanahalli <ananth@linux.ibm.com> Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/161157999039.64773.14950289716779364766.stgit@thinktux.local
Diffstat (limited to 'arch/powerpc/lib/sstep.c')
-rw-r--r--arch/powerpc/lib/sstep.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index f859cbbb6375..e96cff845ef7 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -1445,6 +1445,11 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
#ifdef __powerpc64__
case 4:
+ /*
+ * There are very many instructions with this primary opcode
+ * introduced in the ISA as early as v2.03. However, the ones
+ * we currently emulate were all introduced with ISA 3.0
+ */
if (!cpu_has_feature(CPU_FTR_ARCH_300))
goto unknown_opcode;
@@ -1472,7 +1477,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
* There are other instructions from ISA 3.0 with the same
* primary opcode which do not have emulation support yet.
*/
- return -1;
+ goto unknown_opcode;
#endif
case 7: /* mulli */