diff options
| author | Heiko Carstens <hca@linux.ibm.com> | 2023-03-27 11:37:28 +0200 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2023-04-04 18:34:56 +0200 |
| commit | b94c0ebb1ec752016a3e41bfb66bb51ea905e533 (patch) | |
| tree | 5c94dfb2b30af6c4fb1d551e5adf347a4c21960b /arch/s390/kernel/entry.S | |
| parent | 22ca1e7738025ae38d07c05bae2af934b1b2c11f (diff) | |
s390: enable HAVE_ARCH_STACKLEAK
Add support for the stackleak feature. Whenever the kernel returns to user
space the kernel stack is filled with a poison value.
Enabling this feature is quite expensive: e.g. after instrumenting the
getpid() system call function to have a 4kb stack the result is an
increased runtime of the system call by a factor of 3.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/entry.S')
| -rw-r--r-- | arch/s390/kernel/entry.S | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index fc3d1df09736..d5f8cd4319a4 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -150,6 +150,12 @@ _LPP_OFFSET = __LC_LPP .endm #endif + .macro STACKLEAK_ERASE +#ifdef CONFIG_GCC_PLUGIN_STACKLEAK + brasl %r14,stackleak_erase_on_task_stack +#endif + .endm + GEN_BR_THUNK %r14 .section .kprobes.text, "ax" @@ -300,6 +306,7 @@ ENTRY(system_call) MBEAR %r2 lgr %r3,%r14 brasl %r14,__do_syscall + STACKLEAK_ERASE lctlg %c1,%c1,__LC_USER_ASCE mvc __LC_RETURN_PSW(16),STACK_FRAME_OVERHEAD+__PT_PSW(%r15) BPON @@ -315,6 +322,7 @@ ENDPROC(system_call) ENTRY(ret_from_fork) lgr %r3,%r11 brasl %r14,__ret_from_fork + STACKLEAK_ERASE lctlg %c1,%c1,__LC_USER_ASCE mvc __LC_RETURN_PSW(16),STACK_FRAME_OVERHEAD+__PT_PSW(%r15) BPON @@ -375,6 +383,7 @@ ENTRY(pgm_check_handler) brasl %r14,__do_pgm_check tmhh %r8,0x0001 # returning to user space? jno .Lpgm_exit_kernel + STACKLEAK_ERASE lctlg %c1,%c1,__LC_USER_ASCE BPON stpt __LC_EXIT_TIMER @@ -440,6 +449,7 @@ ENTRY(\name) mvc __LC_RETURN_PSW(16),__PT_PSW(%r11) tmhh %r8,0x0001 # returning to user ? jno 2f + STACKLEAK_ERASE lctlg %c1,%c1,__LC_USER_ASCE BPON stpt __LC_EXIT_TIMER |