Skip to content

Commit

Permalink
s390/entry: remove broken and not needed code
Browse files Browse the repository at this point in the history
LLVM's integrated assembler reports the following error when compiling
entry.S:

<instantiation>:38:5: error: unknown token in expression
 tm %r8,0x0001 # coming from user space?

The correct instruction would have been tmhh instead of tm.
The current code is doing nothing, since (with gas) it get's
translated to a tm instruction which reads from real address 8, which
again contains always zero, and therefore the conditional code is
never executed.
Note that due to the missing displacement gas translates "%r8" into
"8(%r0)".

Also code inspection reveals that this conditional code is not needed.
Therefore remove it.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
  • Loading branch information
Heiko Carstens committed May 6, 2022
1 parent f84d88e commit 29b06ad
Showing 1 changed file with 1 addition and 4 deletions.
5 changes: 1 addition & 4 deletions arch/s390/kernel/entry.S
Original file line number Diff line number Diff line change
Expand Up @@ -473,10 +473,7 @@ ENTRY(\name)
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
MBEAR %r11
stmg %r8,%r9,__PT_PSW(%r11)
tm %r8,0x0001 # coming from user space?
jno 1f
lctlg %c1,%c1,__LC_KERNEL_ASCE
1: lgr %r2,%r11 # pass pointer to pt_regs
lgr %r2,%r11 # pass pointer to pt_regs
brasl %r14,\handler
mvc __LC_RETURN_PSW(16),__PT_PSW(%r11)
tmhh %r8,0x0001 # returning to user ?
Expand Down

0 comments on commit 29b06ad

Please sign in to comment.