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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2020-02-17 10:57:56 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2020-02-18 10:39:03 -0300
commit6e05978f0c30e52420e086cc3156655471e6fb0a (patch)
tree270ec2b2a14ec10a5f50cdc5adcac690d13e029e /debug/backtrace.c
parent631cf64bc1d8306e011ef39f60b8cb6de91bd271 (diff)
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mips: Fix bracktrace result for signal frames
MIPS fallback code handle a frame where its FDE can not be obtained
(for instance a signal frame) by reading the kernel allocated signal frame
and adding '2' to the value of 'sc_pc' [1].  The added value is used to
recognize an end of an EH region on mips16 [2].

The fix adjust the obtained signal frame value and remove the libgcc added
value by checking if the previous frame is a signal frame one.

Checked with backtrace and tst-sigcontext-get_pc tests on mips-linux-gnu
and mips64-linux-gnu.

[1] libgcc/config/mips/linux-unwind.h from gcc code.
[2] gcc/config/mips/mips.h from gcc code.  */
Diffstat (limited to 'debug/backtrace.c')
-rw-r--r--debug/backtrace.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/debug/backtrace.c b/debug/backtrace.c
index cc4b9a5c90..69cf4c23c8 100644
--- a/debug/backtrace.c
+++ b/debug/backtrace.c
@@ -23,6 +23,7 @@
 #include <gnu/lib-names.h>
 #include <stdlib.h>
 #include <unwind.h>
+#include <unwind-arch.h>
 
 struct trace_arg
 {
@@ -78,6 +79,10 @@ backtrace_helper (struct _Unwind_Context *ctx, void *a)
   if (arg->cnt != -1)
     {
       arg->array[arg->cnt] = (void *) unwind_getip (ctx);
+      if (arg->cnt > 0)
+	arg->array[arg->cnt]
+	  = unwind_arch_adjustment (arg->array[arg->cnt - 1],
+				    arg->array[arg->cnt]);
 
       /* Check whether we make any progress.  */
       _Unwind_Word cfa = unwind_getcfa (ctx);