2021-04-08 17:48:17

by Heiko Carstens

[permalink] [raw]
Subject: [GIT PULL] s390 updates for 5.12-rc7

Hi Linus,

please pull a couple of s390 fixes for 5.12-rc7.

Thank you,
Heiko

The following changes since commit 84d572e634e28827d105746c922d8ada425e2d8b:

MAINTAINERS: add backups for s390 vfio drivers (2021-03-28 20:20:33 +0200)

are available in the Git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git tags/s390-5.12-6

for you to fetch changes up to ad31a8c05196a3dc5283b193e9c74a72022d3c65:

s390/setup: use memblock_free_late() to free old stack (2021-04-07 14:37:28 +0200)

----------------------------------------------------------------
s390 updates for 5.12-rc7

- fix incorrect dereference of the ext_params2 external interrupt parameter,
which leads to an instant kernel crash if a pfault interrupt occurs.

- add forgotten stack unwinder support, and fix memory leak for the new
machine check handler stack.

- fix inline assembly register clobbering due to KASAN code instrumentation.

----------------------------------------------------------------
Alexander Gordeev (1):
s390/cpcmd: fix inline assembly register clobbering

Heiko Carstens (2):
s390/irq: fix reading of ext_params2 field from lowcore
s390/setup: use memblock_free_late() to free old stack

Vasily Gorbik (1):
s390/unwind: add machine check handler stack

arch/s390/include/asm/stacktrace.h | 1 +
arch/s390/kernel/cpcmd.c | 6 ++++--
arch/s390/kernel/dumpstack.c | 12 +++++++++++-
arch/s390/kernel/irq.c | 2 +-
arch/s390/kernel/setup.c | 2 +-
5 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/arch/s390/include/asm/stacktrace.h b/arch/s390/include/asm/stacktrace.h
index ee056f4a4fa3..2b543163d90a 100644
--- a/arch/s390/include/asm/stacktrace.h
+++ b/arch/s390/include/asm/stacktrace.h
@@ -12,6 +12,7 @@ enum stack_type {
STACK_TYPE_IRQ,
STACK_TYPE_NODAT,
STACK_TYPE_RESTART,
+ STACK_TYPE_MCCK,
};

struct stack_info {
diff --git a/arch/s390/kernel/cpcmd.c b/arch/s390/kernel/cpcmd.c
index af013b4244d3..2da027359798 100644
--- a/arch/s390/kernel/cpcmd.c
+++ b/arch/s390/kernel/cpcmd.c
@@ -37,10 +37,12 @@ static int diag8_noresponse(int cmdlen)

static int diag8_response(int cmdlen, char *response, int *rlen)
{
+ unsigned long _cmdlen = cmdlen | 0x40000000L;
+ unsigned long _rlen = *rlen;
register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
register unsigned long reg3 asm ("3") = (addr_t) response;
- register unsigned long reg4 asm ("4") = cmdlen | 0x40000000L;
- register unsigned long reg5 asm ("5") = *rlen;
+ register unsigned long reg4 asm ("4") = _cmdlen;
+ register unsigned long reg5 asm ("5") = _rlen;

asm volatile(
" diag %2,%0,0x8\n"
diff --git a/arch/s390/kernel/dumpstack.c b/arch/s390/kernel/dumpstack.c
index 0dc4b258b98d..db1bc00229ca 100644
--- a/arch/s390/kernel/dumpstack.c
+++ b/arch/s390/kernel/dumpstack.c
@@ -79,6 +79,15 @@ static bool in_nodat_stack(unsigned long sp, struct stack_info *info)
return in_stack(sp, info, STACK_TYPE_NODAT, top - THREAD_SIZE, top);
}

+static bool in_mcck_stack(unsigned long sp, struct stack_info *info)
+{
+ unsigned long frame_size, top;
+
+ frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
+ top = S390_lowcore.mcck_stack + frame_size;
+ return in_stack(sp, info, STACK_TYPE_MCCK, top - THREAD_SIZE, top);
+}
+
static bool in_restart_stack(unsigned long sp, struct stack_info *info)
{
unsigned long frame_size, top;
@@ -108,7 +117,8 @@ int get_stack_info(unsigned long sp, struct task_struct *task,
/* Check per-cpu stacks */
if (!in_irq_stack(sp, info) &&
!in_nodat_stack(sp, info) &&
- !in_restart_stack(sp, info))
+ !in_restart_stack(sp, info) &&
+ !in_mcck_stack(sp, info))
goto unknown;

recursion_check:
diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index 601c21791338..714269e10eec 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -174,7 +174,7 @@ void noinstr do_ext_irq(struct pt_regs *regs)

memcpy(&regs->int_code, &S390_lowcore.ext_cpu_addr, 4);
regs->int_parm = S390_lowcore.ext_params;
- regs->int_parm_long = *(unsigned long *)S390_lowcore.ext_params2;
+ regs->int_parm_long = S390_lowcore.ext_params2;

from_idle = !user_mode(regs) && regs->psw.addr == (unsigned long)psw_idle_exit;
if (from_idle)
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 60da976eee6f..72134f9f6ff5 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -354,7 +354,7 @@ static int __init stack_realloc(void)
if (!new)
panic("Couldn't allocate machine check stack");
WRITE_ONCE(S390_lowcore.mcck_stack, new + STACK_INIT_OFFSET);
- memblock_free(old, THREAD_SIZE);
+ memblock_free_late(old, THREAD_SIZE);
return 0;
}
early_initcall(stack_realloc);


2021-04-08 18:22:48

by pr-tracker-bot

[permalink] [raw]
Subject: Re: [GIT PULL] s390 updates for 5.12-rc7

The pull request you sent on Thu, 8 Apr 2021 19:46:51 +0200:

> git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git tags/s390-5.12-6

has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/3fb4f979b4fa1f92a02b538ae86e725b73e703d0

Thank you!

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