From 621de86907d5126e2597b720cbcc09ccffcbaaa0 Mon Sep 17 00:00:00 2001 From: Mitch Phillips Date: Thu, 14 Mar 2019 17:05:53 +0000 Subject: [PATCH] [HWASan] Use less Printf() calls in register dump. Summary: Explicitly print 4 registers/line in each iteration during register dump. Reduces logcat spam as we get a single logcat message per call to Printf(), even if the output isn't newline-terminated. This brings the output format in logcat closer to that of the normal textual dump. Reviewers: eugenis, pcc Reviewed By: pcc Subscribers: kubamracek, #sanitizers, llvm-commits Tags: #sanitizers, #llvm Differential Revision: https://reviews.llvm.org/D59320 llvm-svn: 356166 --- compiler-rt/lib/hwasan/hwasan_report.cpp | 36 ++++++++++++++---------- 1 file changed, 21 insertions(+), 15 deletions(-) diff --git a/compiler-rt/lib/hwasan/hwasan_report.cpp b/compiler-rt/lib/hwasan/hwasan_report.cpp index ddc2749c2ed0..fa2fff7424ee 100644 --- a/compiler-rt/lib/hwasan/hwasan_report.cpp +++ b/compiler-rt/lib/hwasan/hwasan_report.cpp @@ -439,23 +439,29 @@ void ReportTagMismatch(StackTrace *stack, uptr tagged_addr, uptr access_size, // See the frame breakdown defined in __hwasan_tag_mismatch (from // hwasan_tag_mismatch_aarch64.S). -static const char *kDoubleSpace = " "; -static const char *kSingleSpace = " "; void ReportRegisters(uptr *frame, uptr pc) { - Printf("Registers where the failure occurred (pc %p):", pc); + Printf("Registers where the failure occurred (pc %p):\n", pc); - for (unsigned i = 0; i <= 30; i++) { - if (i % 4 == 0) - Printf("\n "); - - // Note - manually inserting a double or single space here based on the - // number of digits in the register name, as our sanitizer Printf does not - // support padding where the content is left aligned (i.e. the format - // specifier "%-2d" will CHECK fail). - Printf(" x%d%s%016llx", i, (i < 10) ? kDoubleSpace : kSingleSpace, - frame[i]); - } - Printf("\n"); + // We explicitly print a single line (4 registers/line) each iteration to + // reduce the amount of logcat error messages printed. Each Printf() will + // result in a new logcat line, irrespective of whether a newline is present, + // and so we wish to reduce the number of Printf() calls we have to make. + Printf(" x0 %016llx x1 %016llx x2 %016llx x3 %016llx\n", + frame[0], frame[1], frame[2], frame[3]); + Printf(" x4 %016llx x5 %016llx x6 %016llx x7 %016llx\n", + frame[4], frame[5], frame[6], frame[7]); + Printf(" x8 %016llx x9 %016llx x10 %016llx x11 %016llx\n", + frame[8], frame[9], frame[10], frame[11]); + Printf(" x12 %016llx x13 %016llx x14 %016llx x15 %016llx\n", + frame[12], frame[13], frame[14], frame[15]); + Printf(" x16 %016llx x17 %016llx x18 %016llx x19 %016llx\n", + frame[16], frame[17], frame[18], frame[19]); + Printf(" x20 %016llx x21 %016llx x22 %016llx x23 %016llx\n", + frame[20], frame[21], frame[22], frame[23]); + Printf(" x24 %016llx x25 %016llx x26 %016llx x27 %016llx\n", + frame[24], frame[25], frame[26], frame[27]); + Printf(" x28 %016llx x29 %016llx x30 %016llx\n", + frame[28], frame[29], frame[30]); } } // namespace __hwasan