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| author | Vineet Gupta <vgupta@synopsys.com> | 2017-12-20 12:37:54 -0800 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2017-12-20 15:16:18 -0800 |
| commit | f5a16b93e6291ba1f65f55647cb4cd8d75ed1b35 (patch) | |
| tree | 4c6243cc717af027d95dff55542b05b067ef16a8 | |
| parent | 79435ac78d160e4c245544d457850a56f805ac0d (diff) | |
| download | linux-f5a16b93e6291ba1f65f55647cb4cd8d75ed1b35.tar.bz2 | |
ARC: handle gcc generated __builtin_trap()
gcc toggle -fisolate-erroneous-paths-dereference (default at -O2
onwards) isolates faulty code paths such as null pointer access, divide
by zero etc by emitting __builtin_trap()
Newer ARC gcc generates TRAP_S 5 instruction which needs to be handled
and treated like any other unexpected exception
- user mode : task terminated with a SEGV
- kernel mode: die() called after register and stack dump
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
| -rw-r--r-- | arch/arc/kernel/traps.c | 6 | ||||
| -rw-r--r-- | arch/arc/kernel/troubleshoot.c | 3 |
2 files changed, 9 insertions, 0 deletions
diff --git a/arch/arc/kernel/traps.c b/arch/arc/kernel/traps.c index bcd7c9fc5d0f..004f4e4a4c10 100644 --- a/arch/arc/kernel/traps.c +++ b/arch/arc/kernel/traps.c @@ -83,6 +83,7 @@ DO_ERROR_INFO(SIGILL, "Illegal Insn (or Seq)", insterror_is_error, ILL_ILLOPC) DO_ERROR_INFO(SIGBUS, "Invalid Mem Access", __weak do_memory_error, BUS_ADRERR) DO_ERROR_INFO(SIGTRAP, "Breakpoint Set", trap_is_brkpt, TRAP_BRKPT) DO_ERROR_INFO(SIGBUS, "Misaligned Access", do_misaligned_error, BUS_ADRALN) +DO_ERROR_INFO(SIGSEGV, "gcc generated __builtin_trap", do_trap5_error, 0) /* * Entry Point for Misaligned Data access Exception, for emulating in software @@ -115,6 +116,8 @@ void do_machine_check_fault(unsigned long address, struct pt_regs *regs) * Thus TRAP_S <n> can be used for specific purpose * -1 used for software breakpointing (gdb) * -2 used by kprobes + * -5 __builtin_trap() generated by gcc (2018.03 onwards) for toggle such as + * -fno-isolate-erroneous-paths-dereference */ void do_non_swi_trap(unsigned long address, struct pt_regs *regs) { @@ -134,6 +137,9 @@ void do_non_swi_trap(unsigned long address, struct pt_regs *regs) kgdb_trap(regs); break; + case 5: + do_trap5_error(address, regs); + break; default: break; } diff --git a/arch/arc/kernel/troubleshoot.c b/arch/arc/kernel/troubleshoot.c index 7d8c1d6c2f60..6e9a0a9a6a04 100644 --- a/arch/arc/kernel/troubleshoot.c +++ b/arch/arc/kernel/troubleshoot.c @@ -163,6 +163,9 @@ static void show_ecr_verbose(struct pt_regs *regs) else pr_cont("Bus Error, check PRM\n"); #endif + } else if (vec == ECR_V_TRAP) { + if (regs->ecr_param == 5) + pr_cont("gcc generated __builtin_trap\n"); } else { pr_cont("Check Programmer's Manual\n"); } |