[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v2] Hexagon: add PC alignment check and exception
From: |
Richard Henderson |
Subject: |
Re: [PATCH v2] Hexagon: add PC alignment check and exception |
Date: |
Mon, 29 Apr 2024 13:59:10 -0700 |
User-agent: |
Mozilla Thunderbird |
On 4/29/24 12:40, Matheus Tavares Bernardino wrote:
@@ -144,6 +148,9 @@ static inline void cpu_get_tb_cpu_state(CPUHexagonState
*env, vaddr *pc,
hex_flags = FIELD_DP32(hex_flags, TB_FLAGS, IS_TIGHT_LOOP, 1);
}
*flags = hex_flags;
+ if (*pc & PCALIGN_MASK) {
+ hexagon_raise_exception_err(env, HEX_EXCP_PC_NOT_ALIGNED, 0);
+ }
}
With the test here ...
diff --git a/target/hexagon/translate.c b/target/hexagon/translate.c
index 47a870f42d..26e6809976 100644
--- a/target/hexagon/translate.c
+++ b/target/hexagon/translate.c
@@ -346,8 +346,9 @@ static void mark_implicit_pred_writes(DisasContext *ctx)
static bool pkt_raises_exception(Packet *pkt)
{
if (check_for_attrib(pkt, A_LOAD) ||
- check_for_attrib(pkt, A_STORE)) {
- return true;
+ check_for_attrib(pkt, A_STORE) ||
+ check_for_attrib(pkt, A_COF)) {
+ return true;
}
... you don't need a change here, because we don't raise the exception from
within the packet.
+run-unaligned_pc run-unaligned_pc_endloop run-unaligned_pc_multi_cof:
+ $(call run-test, $<, $(QEMU) $< 2> $<.stderr,"$< on $(TARGET_NAME)"); \
+ if [ $$? -ne 1 ] ; then \
+ return 1; \
+ fi
+ $(call quiet-command, \
+ grep -q "exception 0x1e" $<.stderr, \
+ "GREP", "exception 0x1e");
What's missing in the patch set is handling this exception in
linux-user/hexagon/cpu_loop.c. This would correspond to misaligned_instruction() in the
kernel.
At which point you could improve the test case to set up a signal handler in C, generate
the exception, and test for correct values in the signal frame.
r~
PS: I think the kernel could be improved to use
force_sig_fault(SIGBUS, BUS_ADRALN, regs->r31);
instead of
force_sig(SIGBUS);
and similarly for misaligned_data_{load,store}.