[RFC PATCH v1 10/19] powerpc/signal: Refactor bad frame logging

From: Christophe Leroy
Date: Wed Aug 12 2020 - 08:06:24 EST


The logging of bad frame appears half a dozen of times
and is pretty similar.

Create signal_fault() fonction to perform that logging.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/kernel/signal.c | 11 +++++++++++
arch/powerpc/kernel/signal.h | 3 +++
arch/powerpc/kernel/signal_32.c | 35 +++++----------------------------
arch/powerpc/kernel/signal_64.c | 15 ++------------
4 files changed, 21 insertions(+), 43 deletions(-)

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 5edded5c5d20..53b4987a45b5 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -355,3 +355,14 @@ static unsigned long get_tm_stackpointer(struct task_struct *tsk)
#endif
return ret;
}
+
+static const char fmt32[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %08lx lr %08lx\n";
+static const char fmt64[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %016lx lr %016lx\n";
+
+void signal_fault(struct task_struct *tsk, struct pt_regs *regs,
+ const char *where, void __user *ptr)
+{
+ if (show_unhandled_signals)
+ printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, tsk->comm,
+ task_pid_nr(tsk), where, ptr, regs->nip, regs->link);
+}
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index fb98731348c3..f610cfafa478 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -93,4 +93,7 @@ static inline int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,

#endif /* !defined(CONFIG_PPC64) */

+void signal_fault(struct task_struct *tsk, struct pt_regs *regs,
+ const char *where, void __user *ptr);
+
#endif /* _POWERPC_ARCH_SIGNAL_H */
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 3356f6aba4ae..d1087dd87174 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -837,12 +837,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
return 0;

badframe:
- if (show_unhandled_signals)
- printk_ratelimited(KERN_INFO
- "%s[%d]: bad frame in handle_rt_signal32: "
- "%p nip %08lx lr %08lx\n",
- tsk->comm, tsk->pid,
- addr, regs->nip, regs->link);
+ signal_fault(tsk, regs, "handle_rt_signal32", addr);

return 1;
}
@@ -1094,12 +1089,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
return 0;

bad:
- if (show_unhandled_signals)
- printk_ratelimited(KERN_INFO
- "%s[%d]: bad frame in sys_rt_sigreturn: "
- "%p nip %08lx lr %08lx\n",
- current->comm, current->pid,
- rt_sf, regs->nip, regs->link);
+ signal_fault(current, regs, "sys_rt_sigreturn", rt_sf);

force_sig(SIGSEGV);
return 0;
@@ -1183,12 +1173,7 @@ SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx,
* We kill the task with a SIGSEGV in this situation.
*/
if (do_setcontext(ctx, regs, 1)) {
- if (show_unhandled_signals)
- printk_ratelimited(KERN_INFO "%s[%d]: bad frame in "
- "sys_debug_setcontext: %p nip %08lx "
- "lr %08lx\n",
- current->comm, current->pid,
- ctx, regs->nip, regs->link);
+ signal_fault(current, regs, "sys_debug_setcontext", ctx);

force_sig(SIGSEGV);
goto out;
@@ -1291,12 +1276,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
return 0;

badframe:
- if (show_unhandled_signals)
- printk_ratelimited(KERN_INFO
- "%s[%d]: bad frame in handle_signal32: "
- "%p nip %08lx lr %08lx\n",
- tsk->comm, tsk->pid,
- frame, regs->nip, regs->link);
+ signal_fault(tsk, regs, "handle_signal32", frame);

return 1;
}
@@ -1367,12 +1347,7 @@ SYSCALL_DEFINE0(sigreturn)
return 0;

badframe:
- if (show_unhandled_signals)
- printk_ratelimited(KERN_INFO
- "%s[%d]: bad frame in sys_sigreturn: "
- "%p nip %08lx lr %08lx\n",
- current->comm, current->pid,
- addr, regs->nip, regs->link);
+ signal_fault(current, regs, "sys_sigreturn", addr);

force_sig(SIGSEGV);
return 0;
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 92d152c1155c..a10b0bb14131 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -66,11 +66,6 @@ struct rt_sigframe {
char abigap[USER_REDZONE_SIZE];
} __attribute__ ((aligned (16)));

-static const char fmt32[] = KERN_INFO \
- "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
-static const char fmt64[] = KERN_INFO \
- "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
-
/*
* This computes a quad word aligned pointer inside the vmx_reserve array
* element. For historical reasons sigcontext might not be quad word aligned,
@@ -801,10 +796,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
return 0;

badframe:
- if (show_unhandled_signals)
- printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
- current->comm, current->pid, "rt_sigreturn",
- (long)uc, regs->nip, regs->link);
+ signal_fault(current, regs, "rt_sigreturn", uc);

force_sig(SIGSEGV);
return 0;
@@ -913,10 +905,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
return 0;

badframe:
- if (show_unhandled_signals)
- printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
- tsk->comm, tsk->pid, "setup_rt_frame",
- (long)frame, regs->nip, regs->link);
+ signal_fault(current, regs, "handle_rt_signal64", frame);

return 1;
}
--
2.25.0