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Diffstat (limited to 'results/classifier/deepseek-r1:32b/output/runtime/1128')
| -rw-r--r-- | results/classifier/deepseek-r1:32b/output/runtime/1128 | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/results/classifier/deepseek-r1:32b/output/runtime/1128 b/results/classifier/deepseek-r1:32b/output/runtime/1128 new file mode 100644 index 000000000..902f0bafe --- /dev/null +++ b/results/classifier/deepseek-r1:32b/output/runtime/1128 @@ -0,0 +1,27 @@ + + + +PPC: `spr_write_xer` doesn't set flag bits in `cpu_xer` +Description of problem: +`spr_write_xer()` does not set the `ca`, `ov`, `so`, `ca32`, `ov32` etc. flag bits in the `cpu_xer` variable. + +In fact it copies all bits from the source `GPR` and _excludes_ each flag bit. + +This is not a problem for execution since `spr_read_xer()` gets the flag bits from `cpu_ca/ov/so...` and not from `cpu_xer`. + +Nonetheless it is problem for tools which trace the execution in QEMU (e.g. https://github.com/BinaryAnalysisPlatform/qemu). + +A fix would be to remove the `~` in https://gitlab.com/qemu-project/qemu/-/blob/master/target/ppc/translate.c#L481 +Steps to reproduce: +Haven't found out yet how to debug QEMU so the TCGv values can be investigated. But in general one need to: + +- Execute a binary which executes something like: +``` +r4 = 0xffffffffffffffff +mtxer r4 +``` +and check the `cpu_xer` value after the `xer` write. + +Checking the debug logs (`in_asm,cpu`) doesn't work, since the `xer` value in the logs is not taken directly from `cpu_xer`. +Additional information: +Code ref: https://gitlab.com/qemu-project/qemu/-/blob/master/target/ppc/translate.c#L480-L483 |