diff options
authorDmitry Safonov <dima@arista.com>2020-06-08 21:30:16 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-09 09:39:10 -0700
commit34135eacae6497d9c7bfca450f6c33e5245c92d2 (patch)
parentee65ca01c62cd89cea6192017806b55c34f1cfda (diff)
arm: wire up dump_backtrace_{entry,stm}
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. Now that c_backtrace() always emits correct loglvl, use it for printing. [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/20200418201944.482088-8-dima@arista.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 7 insertions, 5 deletions
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 014fb5ad3a8b..0aa55dc025a1 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -68,13 +68,15 @@ void dump_backtrace_entry(unsigned long where, unsigned long from,
unsigned long end = frame + 4 + sizeof(struct pt_regs);
- printk("[<%08lx>] (%ps) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);
+ printk("%s[<%08lx>] (%ps) from [<%08lx>] (%pS)\n",
+ loglvl, where, (void *)where, from, (void *)from);
- printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
+ printk("%sFunction entered at [<%08lx>] from [<%08lx>]\n",
+ loglvl, where, from);
if (in_entry_text(from) && end <= ALIGN(frame, THREAD_SIZE))
- dump_mem("", "Exception stack", frame + 4, end);
+ dump_mem(loglvl, "Exception stack", frame + 4, end);
void dump_backtrace_stm(u32 *stack, u32 instruction, const char *loglvl)
@@ -89,12 +91,12 @@ void dump_backtrace_stm(u32 *stack, u32 instruction, const char *loglvl)
if (++x == 6) {
x = 0;
p = str;
- printk("%s\n", str);
+ printk("%s%s\n", loglvl, str);
if (p != str)
- printk("%s\n", str);
+ printk("%s%s\n", loglvl, str);