On 9/3/24 03:28, Helge Deller wrote:
While adding hppa64 support, the psw_v variable got extended from 32 to 64
bits. So, when packaging the PSW-V bit from the psw_v variable for interrupt
processing, check bit 31 instead the 63th (sign) bit.
This fixes a hard to find Linux kernel boot issue where the loss of the PSW-V
bit due to an ITLB interruption in the middle of a series of ds/addc
instructions (from the divU milicode library) generated the wrong division
result and thus triggered a Linux kernel crash.
Link: https://lore.kernel.org/lkml/718b8afe-222f-4b3a-96d3-93af0e4ceff1@xxxxxxxxxxxx/
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Helge Deller <deller@xxxxxx>
Fixes: 931adff31478 ("target/hppa: Update cpu_hppa_get/put_psw for hppa64")
diff --git a/target/hppa/helper.c b/target/hppa/helper.c
index b79ddd8184..d4b1a3cd5a 100644
--- a/target/hppa/helper.c
+++ b/target/hppa/helper.c
@@ -53,7 +53,7 @@ target_ulong cpu_hppa_get_psw(CPUHPPAState *env)
}
psw |= env->psw_n * PSW_N;
- psw |= (env->psw_v < 0) * PSW_V;
+ psw |= ((env->psw_v >> 31) & 1) * PSW_V;
psw |= env->psw | env->psw_xb;
return psw;
While this is correct, we should also update cpu.h:
- target_long psw_v; /* in most significant bit */
+ target_long psw_v; /* in bit 31 */
With that,
Reviewed-by: Richard Henderson <richard.henderson@xxxxxxxxxx>
r~
