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authorDmitry Safonov <dima@arista.com>2020-06-09 06:30:07 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-09 18:39:10 +0200
commit5489ab50c22771ddcad014968141b0d104d650a3 (patch)
treeda45382c2f04f70bf5f8abecb8132baf70f38874 /arch/arm/kernel
parentarc: add show_stack_loglvl() (diff)
downloadlinux-5489ab50c22771ddcad014968141b0d104d650a3.tar.xz
linux-5489ab50c22771ddcad014968141b0d104d650a3.zip
arm/asm: add loglvl to c_backtrace()
Currently, the log-level of show_stack() depends on a platform realization. It creates situations where the headers are printed with lower log level or higher than the stacktrace (depending on a platform or user). Furthermore, it forces the logic decision from user to an architecture side. In result, some users as sysrq/kdb/etc are doing tricks with temporary rising console_loglevel while printing their messages. And in result it not only may print unwanted messages from other CPUs, but also omit printing at all in the unlucky case where the printk() was deferred. Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier approach than introducing more printk buffers. Also, it will consolidate printings with headers. Add log level argument to c_backtrace() as a preparation for introducing show_stack_loglvl(). [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will@kernel.org> Link: http://lkml.kernel.org/r/20200418201944.482088-5-dima@arista.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/traps.c9
-rw-r--r--arch/arm/kernel/unwind.c2
2 files changed, 6 insertions, 5 deletions
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 316a7687f813..7bba15fdce9f 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -62,7 +62,8 @@ __setup("user_debug=", user_debug_setup);
static void dump_mem(const char *, const char *, unsigned long, unsigned long);
-void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame)
+void dump_backtrace_entry(unsigned long where, unsigned long from,
+ unsigned long frame, const char *loglvl)
{
unsigned long end = frame + 4 + sizeof(struct pt_regs);
@@ -76,7 +77,7 @@ void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long
dump_mem("", "Exception stack", frame + 4, end);
}
-void dump_backtrace_stm(u32 *stack, u32 instruction)
+void dump_backtrace_stm(u32 *stack, u32 instruction, const char *loglvl)
{
char str[80], *p;
unsigned int x;
@@ -238,7 +239,7 @@ static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
pr_cont("\n");
if (ok)
- c_backtrace(fp, mode);
+ c_backtrace(fp, mode, NULL);
}
#endif
@@ -666,7 +667,7 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
dump_instr("", regs);
if (user_mode(regs)) {
__show_regs(regs);
- c_backtrace(frame_pointer(regs), processor_mode(regs));
+ c_backtrace(frame_pointer(regs), processor_mode(regs), NULL);
}
}
#endif
diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c
index 11a964fd66f4..343cc27b36c4 100644
--- a/arch/arm/kernel/unwind.c
+++ b/arch/arm/kernel/unwind.c
@@ -493,7 +493,7 @@ void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk)
urc = unwind_frame(&frame);
if (urc < 0)
break;
- dump_backtrace_entry(where, frame.pc, frame.sp - 4);
+ dump_backtrace_entry(where, frame.pc, frame.sp - 4, NULL);
}
}