Commit 86147e3c authored by Liav Rehana's avatar Liav Rehana Committed by Vineet Gupta

ARC: use correct offset in pt_regs for saving/restoring user mode r25

User mode callee regs are explicitly collected before signal delivery or
breakpoint trap. r25 is special for kernel as it serves as task pointer,
so user mode value is clobbered very early. It is saved in pt_regs where
generally only scratch (aka caller saved) regs are saved.

The code to access the corresponding pt_regs location had a subtle bug as
it was using load/store with scaling of offset, whereas the offset was already
byte wise correct. So fix this by replacing LD.AS with a standard LD

Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarLiav Rehana <liavr@mellanox.com>
Reviewed-by: default avatarAlexey Brodkin <abrodkin@synopsys.com>
[vgupta: rewrote title and commit log]
Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent 45c3b08a
...@@ -142,7 +142,7 @@ ...@@ -142,7 +142,7 @@
#ifdef CONFIG_ARC_CURR_IN_REG #ifdef CONFIG_ARC_CURR_IN_REG
; Retrieve orig r25 and save it with rest of callee_regs ; Retrieve orig r25 and save it with rest of callee_regs
ld.as r12, [r12, PT_user_r25] ld r12, [r12, PT_user_r25]
PUSH r12 PUSH r12
#else #else
PUSH r25 PUSH r25
...@@ -198,7 +198,7 @@ ...@@ -198,7 +198,7 @@
; SP is back to start of pt_regs ; SP is back to start of pt_regs
#ifdef CONFIG_ARC_CURR_IN_REG #ifdef CONFIG_ARC_CURR_IN_REG
st.as r12, [sp, PT_user_r25] st r12, [sp, PT_user_r25]
#endif #endif
.endm .endm
......
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