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| author |   Heiko Carstens <hca@linux.ibm.com> | 2020-11-11 18:46:26 +0100 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2020-11-20 19:17:24 +0100 |
| commit | 0cd9b7230cc57b0f9cfd13ef5c3830c7db1a68d4 (patch) | |
| tree | 2737925e71c97d28634b6412e12f371bad9a3df0 | |
| parent | Merge branch 'fixes' into features (diff) | |
| download | linux-dev-0cd9b7230cc57b0f9cfd13ef5c3830c7db1a68d4.tar.xz linux-dev-0cd9b7230cc57b0f9cfd13ef5c3830c7db1a68d4.zip | |
s390: add separate program check exit path
System call and program check handler both use the system call exit
path when returning to previous context. However the program check
handler jumps right to the end of the system call exit path if the
previous context is kernel context.
This lead to the quite odd double disabling of interrupts in the
system call exit path introduced with commit ce9dfafe29be ("s390:
fix system call exit path").
To avoid that have a separate program check handler exit path if the
previous context is kernel context.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| -rw-r--r-- | arch/s390/kernel/entry.S | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 5346545b9860..0a7811d993a7 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -430,8 +430,6 @@ ENTRY(system_call) TSTMSK __LC_CPU_FLAGS,(_CIF_WORK-_CIF_FPU) jnz .Lsysc_work BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP -.Lsysc_restore: - DISABLE_INTS TSTMSK __LC_CPU_FLAGS, _CIF_FPU jz .Lsysc_skip_fpu brasl %r14,load_fpu_regs @@ -709,10 +707,20 @@ ENTRY(pgm_check_handler) .Lpgm_return: LOCKDEP_SYS_EXIT tm __PT_PSW+1(%r11),0x01 # returning to user ? - jno .Lsysc_restore + jno .Lpgm_restore TSTMSK __PT_FLAGS(%r11),_PIF_SYSCALL jo .Lsysc_do_syscall j .Lsysc_tif +.Lpgm_restore: + DISABLE_INTS + TSTMSK __LC_CPU_FLAGS, _CIF_FPU + jz .Lpgm_skip_fpu + brasl %r14,load_fpu_regs +.Lpgm_skip_fpu: + mvc __LC_RETURN_PSW(16),__PT_PSW(%r11) + stpt __LC_EXIT_TIMER + lmg %r0,%r15,__PT_R0(%r11) + b __LC_RETURN_LPSWE # # PER event in supervisor state, must be kprobes |