From 6592ceed489043051d02d41dc71f51e8ef8aa6f0 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Wed, 18 Jul 2018 19:17:39 +0100 Subject: [PATCH] microMIPS: Add SYSCALL instruction decoding Fix a bug with commit 4cc0665f24bb ("microMIPS support"), , and add missing microMIPS SYSCALL instruction decoding needed to determine the location to put a breakpoint at when single-stepping though a syscall. gdb/ * mips-tdep.c (micromips_next_pc): Add SYSCALL instruction decoding. --- gdb/ChangeLog | 5 +++++ gdb/mips-tdep.c | 30 ++++++++++++++++++++++++------ 2 files changed, 29 insertions(+), 6 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 7e7f88a..a30780a 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2018-07-18 Maciej W. Rozycki + + * mips-tdep.c (micromips_next_pc): Add SYSCALL instruction + decoding. + 2018-07-17 Tom Tromey * guile/scm-param.c (pascm_set_func, pascm_show_func) diff --git a/gdb/mips-tdep.c b/gdb/mips-tdep.c index 36fae02..37a12a9 100644 --- a/gdb/mips-tdep.c +++ b/gdb/mips-tdep.c @@ -1898,12 +1898,30 @@ micromips_next_pc (struct regcache *regcache, CORE_ADDR pc) switch (micromips_op (insn >> 16)) { case 0x00: /* POOL32A: bits 000000 */ - if (b0s6_op (insn) == 0x3c - /* POOL32Axf: bits 000000 ... 111100 */ - && (b6s10_ext (insn) & 0x2bf) == 0x3c) - /* JALR, JALR.HB: 000000 000x111100 111100 */ - /* JALRS, JALRS.HB: 000000 010x111100 111100 */ - pc = regcache_raw_get_signed (regcache, b0s5_reg (insn >> 16)); + switch (b0s6_op (insn)) + { + case 0x3c: /* POOL32Axf: bits 000000 ... 111100 */ + switch (b6s10_ext (insn)) + { + case 0x3c: /* JALR: 000000 0000111100 111100 */ + case 0x7c: /* JALR.HB: 000000 0001111100 111100 */ + case 0x13c: /* JALRS: 000000 0100111100 111100 */ + case 0x17c: /* JALRS.HB: 000000 0101111100 111100 */ + pc = regcache_raw_get_signed (regcache, + b0s5_reg (insn >> 16)); + break; + case 0x22d: /* SYSCALL: 000000 1000101101 111100 */ + { + struct gdbarch_tdep *tdep; + + tdep = gdbarch_tdep (gdbarch); + if (tdep->syscall_next_pc != NULL) + pc = tdep->syscall_next_pc (get_current_frame ()); + } + break; + } + break; + } break; case 0x10: /* POOL32I: bits 010000 */ -- 2.7.4