s390 updates for 5.5-rc3

- Fix unwinding from irq context of interrupted user process.
 
 - Add purgatory build missing symbols check. That helped to uncover and
   fix missing symbols when built with kasan support enabled.
 
 - Couple of ftrace fixes. Avoid broken stack trace and fix recursion
   loop in function_graph tracer.
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Merge tag 's390-5.5-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 fixes from Vasily Gorbik:

 - Fix unwinding from irq context of interrupted user process.

 - Add purgatory build missing symbols check. That helped to uncover and
   fix missing symbols when built with kasan support enabled.

 - Couple of ftrace fixes. Avoid broken stack trace and fix recursion
   loop in function_graph tracer.

* tag 's390-5.5-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/ftrace: save traced function caller
  s390/unwind: stop gracefully at user mode pt_regs in irq stack
  s390/purgatory: do not build purgatory with kcov, kasan and friends
  s390/purgatory: Make sure we fail the build if purgatory has missing symbols
  s390/ftrace: fix endless recursion in function_graph tracer
This commit is contained in:
Linus Torvalds 2019-12-21 12:17:14 -08:00
commit 60b04df6bf
6 changed files with 32 additions and 11 deletions

View File

@ -194,9 +194,9 @@ static inline unsigned long long get_tod_clock_monotonic(void)
{
unsigned long long tod;
preempt_disable();
preempt_disable_notrace();
tod = get_tod_clock() - *(unsigned long long *) &tod_clock_base[1];
preempt_enable();
preempt_enable_notrace();
return tod;
}

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@ -35,6 +35,7 @@ EXPORT_SYMBOL(_mcount)
ENTRY(ftrace_caller)
.globl ftrace_regs_caller
.set ftrace_regs_caller,ftrace_caller
stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller
lgr %r1,%r15
#if !(defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT))
aghi %r0,MCOUNT_RETURN_FIXUP

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@ -36,10 +36,17 @@ static bool update_stack_info(struct unwind_state *state, unsigned long sp)
return true;
}
static inline bool is_task_pt_regs(struct unwind_state *state,
struct pt_regs *regs)
static inline bool is_final_pt_regs(struct unwind_state *state,
struct pt_regs *regs)
{
return task_pt_regs(state->task) == regs;
/* user mode or kernel thread pt_regs at the bottom of task stack */
if (task_pt_regs(state->task) == regs)
return true;
/* user mode pt_regs at the bottom of irq stack */
return state->stack_info.type == STACK_TYPE_IRQ &&
state->stack_info.end - sizeof(struct pt_regs) == (unsigned long)regs &&
READ_ONCE_NOCHECK(regs->psw.mask) & PSW_MASK_PSTATE;
}
bool unwind_next_frame(struct unwind_state *state)
@ -80,7 +87,7 @@ bool unwind_next_frame(struct unwind_state *state)
if (!on_stack(info, sp, sizeof(struct pt_regs)))
goto out_err;
regs = (struct pt_regs *) sp;
if (is_task_pt_regs(state, regs))
if (is_final_pt_regs(state, regs))
goto out_stop;
ip = READ_ONCE_NOCHECK(regs->psw.addr);
sp = READ_ONCE_NOCHECK(regs->gprs[15]);

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@ -1,3 +1,4 @@
purgatory
purgatory.chk
purgatory.lds
purgatory.ro

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@ -4,7 +4,7 @@ OBJECT_FILES_NON_STANDARD := y
purgatory-y := head.o purgatory.o string.o sha256.o mem.o
targets += $(purgatory-y) purgatory.lds purgatory purgatory.ro
targets += $(purgatory-y) purgatory.lds purgatory purgatory.chk purgatory.ro
PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y))
$(obj)/sha256.o: $(srctree)/lib/crypto/sha256.c FORCE
@ -15,8 +15,10 @@ CFLAGS_sha256.o := -D__DISABLE_EXPORTS
$(obj)/mem.o: $(srctree)/arch/s390/lib/mem.S FORCE
$(call if_changed_rule,as_o_S)
$(obj)/string.o: $(srctree)/arch/s390/lib/string.c FORCE
$(call if_changed_rule,cc_o_c)
KCOV_INSTRUMENT := n
GCOV_PROFILE := n
UBSAN_SANITIZE := n
KASAN_SANITIZE := n
KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes
KBUILD_CFLAGS += -Wno-pointer-sign -Wno-sign-compare
@ -26,15 +28,22 @@ KBUILD_CFLAGS += $(CLANG_FLAGS)
KBUILD_CFLAGS += $(call cc-option,-fno-PIE)
KBUILD_AFLAGS := $(filter-out -DCC_USING_EXPOLINE,$(KBUILD_AFLAGS))
LDFLAGS_purgatory := -r --no-undefined -nostdlib -z nodefaultlib -T
# Since we link purgatory with -r unresolved symbols are not checked, so we
# also link a purgatory.chk binary without -r to check for unresolved symbols.
PURGATORY_LDFLAGS := -nostdlib -z nodefaultlib
LDFLAGS_purgatory := -r $(PURGATORY_LDFLAGS) -T
LDFLAGS_purgatory.chk := -e purgatory_start $(PURGATORY_LDFLAGS)
$(obj)/purgatory: $(obj)/purgatory.lds $(PURGATORY_OBJS) FORCE
$(call if_changed,ld)
$(obj)/purgatory.chk: $(obj)/purgatory FORCE
$(call if_changed,ld)
OBJCOPYFLAGS_purgatory.ro := -O elf64-s390
OBJCOPYFLAGS_purgatory.ro += --remove-section='*debug*'
OBJCOPYFLAGS_purgatory.ro += --remove-section='.comment'
OBJCOPYFLAGS_purgatory.ro += --remove-section='.note.*'
$(obj)/purgatory.ro: $(obj)/purgatory FORCE
$(obj)/purgatory.ro: $(obj)/purgatory $(obj)/purgatory.chk FORCE
$(call if_changed,objcopy)
$(obj)/kexec-purgatory.o: $(obj)/kexec-purgatory.S $(obj)/purgatory.ro FORCE

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@ -0,0 +1,3 @@
// SPDX-License-Identifier: GPL-2.0
#define __HAVE_ARCH_MEMCMP /* arch function */
#include "../lib/string.c"