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authorHeiko Carstens2022-02-22 14:53:47 +0100
committerVasily Gorbik2022-03-01 20:41:28 +0100
commit1389f17937a03fe4ec71b094e1aa6530a901963e (patch)
tree5ab2532ac948879baad3422c400d3c70482cd0c5 /arch
parent9fa881f7e3c74ce6626d166bca9397e5d925937f (diff)
s390/ftrace: fix arch_ftrace_get_regs implementation
arch_ftrace_get_regs is supposed to return a struct pt_regs pointer only if the pt_regs structure contains all register contents, which means it must have been populated when created via ftrace_regs_caller. If it was populated via ftrace_caller the contents are not complete (the psw mask part is missing), and therefore a NULL pointer needs be returned. The current code incorrectly always returns a struct pt_regs pointer. Fix this by adding another pt_regs flag which indicates if the contents are complete, and fix arch_ftrace_get_regs accordingly. Fixes: 894979689d3a ("s390/ftrace: provide separate ftrace_caller/ftrace_regs_caller implementations") Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reported-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@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')
-rw-r--r--arch/s390/include/asm/ftrace.h10
-rw-r--r--arch/s390/include/asm/ptrace.h2
-rw-r--r--arch/s390/kernel/ftrace.c2
-rw-r--r--arch/s390/kernel/mcount.S9
4 files changed, 18 insertions, 5 deletions
diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h
index 267f70f4393f..6f80ec9c04be 100644
--- a/arch/s390/include/asm/ftrace.h
+++ b/arch/s390/include/asm/ftrace.h
@@ -47,15 +47,17 @@ struct ftrace_regs {
static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs)
{
- return &fregs->regs;
+ struct pt_regs *regs = &fregs->regs;
+
+ if (test_pt_regs_flag(regs, PIF_FTRACE_FULL_REGS))
+ return regs;
+ return NULL;
}
static __always_inline void ftrace_instruction_pointer_set(struct ftrace_regs *fregs,
unsigned long ip)
{
- struct pt_regs *regs = arch_ftrace_get_regs(fregs);
-
- regs->psw.addr = ip;
+ fregs->regs.psw.addr = ip;
}
/*
diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h
index 4ffa8e7f0ed3..ddb70fb13fbc 100644
--- a/arch/s390/include/asm/ptrace.h
+++ b/arch/s390/include/asm/ptrace.h
@@ -15,11 +15,13 @@
#define PIF_EXECVE_PGSTE_RESTART 1 /* restart execve for PGSTE binaries */
#define PIF_SYSCALL_RET_SET 2 /* return value was set via ptrace */
#define PIF_GUEST_FAULT 3 /* indicates program check in sie64a */
+#define PIF_FTRACE_FULL_REGS 4 /* all register contents valid (ftrace) */
#define _PIF_SYSCALL BIT(PIF_SYSCALL)
#define _PIF_EXECVE_PGSTE_RESTART BIT(PIF_EXECVE_PGSTE_RESTART)
#define _PIF_SYSCALL_RET_SET BIT(PIF_SYSCALL_RET_SET)
#define _PIF_GUEST_FAULT BIT(PIF_GUEST_FAULT)
+#define _PIF_FTRACE_FULL_REGS BIT(PIF_FTRACE_FULL_REGS)
#ifndef __ASSEMBLY__
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index 5026d218066d..89c0870d5679 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -326,7 +326,7 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
regs = ftrace_get_regs(fregs);
p = get_kprobe((kprobe_opcode_t *)ip);
- if (unlikely(!p) || kprobe_disabled(p))
+ if (!regs || unlikely(!p) || kprobe_disabled(p))
goto out;
if (kprobe_running()) {
diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S
index 39bcc0e39a10..a24177dcd12a 100644
--- a/arch/s390/kernel/mcount.S
+++ b/arch/s390/kernel/mcount.S
@@ -27,6 +27,7 @@ ENDPROC(ftrace_stub)
#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
#define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW)
#define STACK_PTREGS_ORIG_GPR2 (STACK_PTREGS + __PT_ORIG_GPR2)
+#define STACK_PTREGS_FLAGS (STACK_PTREGS + __PT_FLAGS)
#ifdef __PACK_STACK
/* allocate just enough for r14, r15 and backchain */
#define TRACED_FUNC_FRAME_SIZE 24
@@ -57,6 +58,14 @@ ENDPROC(ftrace_stub)
.if \allregs == 1
stg %r14,(STACK_PTREGS_PSW)(%r15)
stosm (STACK_PTREGS_PSW)(%r15),0
+#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES
+ mvghi STACK_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS
+#else
+ lghi %r14,_PIF_FTRACE_FULL_REGS
+ stg %r14,STACK_PTREGS_FLAGS(%r15)
+#endif
+ .else
+ xc STACK_PTREGS_FLAGS(8,%r15),STACK_PTREGS_FLAGS(%r15)
.endif
lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address