[PATCH v3 2/2] powerpc/xmon: Disable tracing when entering xmon
From: Breno Leitao <leitao@debian.org>
Date: 2017-08-02 20:14:18
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
If tracing is enabled and you get into xmon, the tracing buffer continues to be updated, causing possible loss of data and unnecessary tracing information coming from xmon functions. This patch simple disables tracing when entering xmon, and re-enables it if the kernel is resumed (with 'x'). Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Naveen N. Rao <redacted> --- arch/powerpc/xmon/xmon.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index e0522f60f0ee..d038e7db44c4 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c@@ -89,6 +89,7 @@ static unsigned long nidump = 16; static unsigned long ncsum = 4096; static int termch; static char tmpstr[128]; +static int tracing_enabled; static long bus_error_jmp[JMP_BUF_LEN]; static int catch_memory_errors;
@@ -462,6 +463,9 @@ static int xmon_core(struct pt_regs *regs, int fromipi) local_irq_save(flags); hard_irq_disable(); + tracing_enabled = tracing_is_on(); + tracing_off(); + bp = in_breakpoint_table(regs->nip, &offset); if (bp != NULL) { regs->nip = bp->address + offset;
@@ -982,6 +986,8 @@ cmds(struct pt_regs *excp) break; case 'x': case 'X': + if (tracing_enabled) + tracing_on(); return cmd; case EOF: printf(" <no input ...>\n");
@@ -2241,8 +2247,6 @@ static void dump_tracing(void) ftrace_dump(DUMP_ORIG); else ftrace_dump(DUMP_ALL); - - tracing_on(); } #ifdef CONFIG_PPC64
--
2.13.2