gdb/testsuite/gdb.arch/arm-single-step-kernel-helper.exp

# Copyright (C) 2016-2021 Free Software Foundation, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

if { ![is_aarch32_target] } {
    verbose "Skipping ${gdb_test_file_name}."
    return
}

standard_testfile

if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile} \
    [list debug]] } {
    return -1
}

if { ![runto_main] } {
    return -1
}

# Check kernel helpers are supported or not.

set kernel_helper_supported 0
gdb_test_multiple "p *kernel_user_helper_version" \
    "check kernel helper version" {
	-re " = ($decimal)\r\n$gdb_prompt $" {
	    if { $expect_out(1,string) >= 1 } {
		set kernel_helper_supported 1
	    }
	}
    }

if { !$kernel_helper_supported } {
    unsupported "kernel doesn't have helpers"
    return 0
}

# Get the instruction branching to kernel helper, they can be
# blx rN or bx rN.
set branch_to_kernel_helper 0
set branch_insn "bl?x\[ \t\]*r${decimal}"
set test "disassemble main"
gdb_test_multiple $test $test {
    -re ".*($hex) <\\+$decimal>:\[ \t\]+$branch_insn" {
	set branch_to_kernel_helper $expect_out(1,string)
	exp_continue
    }
    -re ".*$gdb_prompt $" {
    }
}

if { ![gdb_assert $branch_to_kernel_helper \
	   "find instruction branch to kernel helper"] } {
    return
}

with_test_prefix "single-step" {
    gdb_breakpoint "*${branch_to_kernel_helper}"
    gdb_continue_to_breakpoint "branch to kernel helper"
    gdb_test "si"

    set test "bt"
    gdb_test_multiple $test $test {
	-re "#0  \[^\\r\\n\]*main .*\r\n$gdb_prompt $" {
	    # Test that the program still stops in main rather than
	    # somewhere else.
	    pass $test
	}
	-re "#0  0xffff0fe0 .*\r\n$gdb_prompt $" {
	    # AArch64 linux kernel can do hardware single step, so
	    # the program can stop at kernel helper.
	    pass $test
	}

    }

    delete_breakpoints
}

with_test_prefix "cond-breakpoint" {
    gdb_breakpoint "*${branch_to_kernel_helper} if i > 5"
    gdb_continue_to_breakpoint "branch to kernel helper"
    gdb_test "p i" " = 6"

    delete_breakpoints
}