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author | Jon Medhurst <tixy@yxit.co.uk> | 2011-08-28 16:35:11 +0100 |
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committer | Jon Medhurst <tixy@yxit.co.uk> | 2011-09-20 18:17:43 +0000 |
commit | 68f360e753668b61366b7b4b2a5aa77ac5157c37 (patch) | |
tree | 41d56fb8ab553eb24da427f56e1cef6ad7da9830 /arch/arm/kernel | |
parent | 2c89240b630e94c1a5949860b7bfcf28130bd9c8 (diff) | |
download | talos-op-linux-68f360e753668b61366b7b4b2a5aa77ac5157c37.tar.gz talos-op-linux-68f360e753668b61366b7b4b2a5aa77ac5157c37.zip |
ARM: kprobes: Add decoding table self-consistency tests
These check that the bitmask and match value used in the decoding tables
are self consistent.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r-- | arch/arm/kernel/kprobes-test.c | 103 |
1 files changed, 99 insertions, 4 deletions
diff --git a/arch/arm/kernel/kprobes-test.c b/arch/arm/kernel/kprobes-test.c index b12be0fe183c..6c0946c023f8 100644 --- a/arch/arm/kernel/kprobes-test.c +++ b/arch/arm/kernel/kprobes-test.c @@ -443,6 +443,92 @@ static int run_api_tests(long (*func)(long, long)) /* + * Decoding table self-consistency tests + */ + +static const int decode_struct_sizes[NUM_DECODE_TYPES] = { + [DECODE_TYPE_TABLE] = sizeof(struct decode_table), + [DECODE_TYPE_CUSTOM] = sizeof(struct decode_custom), + [DECODE_TYPE_SIMULATE] = sizeof(struct decode_simulate), + [DECODE_TYPE_EMULATE] = sizeof(struct decode_emulate), + [DECODE_TYPE_OR] = sizeof(struct decode_or), + [DECODE_TYPE_REJECT] = sizeof(struct decode_reject) +}; + +static int table_iter(const union decode_item *table, + int (*fn)(const struct decode_header *, void *), + void *args) +{ + const struct decode_header *h = (struct decode_header *)table; + int result; + + for (;;) { + enum decode_type type = h->type_regs.bits & DECODE_TYPE_MASK; + + if (type == DECODE_TYPE_END) + return 0; + + result = fn(h, args); + if (result) + return result; + + h = (struct decode_header *) + ((uintptr_t)h + decode_struct_sizes[type]); + + } +} + +static int table_test_fail(const struct decode_header *h, const char* message) +{ + + pr_err("FAIL: kprobes test failure \"%s\" (mask %08x, value %08x)\n", + message, h->mask.bits, h->value.bits); + return -EINVAL; +} + +struct table_test_args { + const union decode_item *root_table; + u32 parent_mask; + u32 parent_value; +}; + +static int table_test_fn(const struct decode_header *h, void *args) +{ + struct table_test_args *a = (struct table_test_args *)args; + enum decode_type type = h->type_regs.bits & DECODE_TYPE_MASK; + + if (h->value.bits & ~h->mask.bits) + return table_test_fail(h, "Match value has bits not in mask"); + + if ((h->mask.bits & a->parent_mask) != a->parent_mask) + return table_test_fail(h, "Mask has bits not in parent mask"); + + if ((h->value.bits ^ a->parent_value) & a->parent_mask) + return table_test_fail(h, "Value is inconsistent with parent"); + + if (type == DECODE_TYPE_TABLE) { + struct decode_table *d = (struct decode_table *)h; + struct table_test_args args2 = *a; + args2.parent_mask = h->mask.bits; + args2.parent_value = h->value.bits; + return table_iter(d->table.table, table_test_fn, &args2); + } + + return 0; +} + +static int table_test(const union decode_item *table) +{ + struct table_test_args args = { + .root_table = table, + .parent_mask = 0, + .parent_value = 0 + }; + return table_iter(args.root_table, table_test_fn, &args); +} + + +/* * Framework for instruction set test cases */ @@ -1117,8 +1203,15 @@ end: * Top level test functions */ -static int run_test_cases(void (*tests)(void)) +static int run_test_cases(void (*tests)(void), const union decode_item *table) { + int ret; + + pr_info(" Check decoding tables\n"); + ret = table_test(table); + if (ret) + return ret; + pr_info(" Run test cases\n"); tests(); @@ -1140,7 +1233,7 @@ static int __init run_all_tests(void) goto out; pr_info("ARM instruction simulation\n"); - ret = run_test_cases(kprobe_arm_test_cases); + ret = run_test_cases(kprobe_arm_test_cases, kprobe_decode_arm_table); if (ret) goto out; @@ -1162,12 +1255,14 @@ static int __init run_all_tests(void) goto out; pr_info("16-bit Thumb instruction simulation\n"); - ret = run_test_cases(kprobe_thumb16_test_cases); + ret = run_test_cases(kprobe_thumb16_test_cases, + kprobe_decode_thumb16_table); if (ret) goto out; pr_info("32-bit Thumb instruction simulation\n"); - ret = run_test_cases(kprobe_thumb32_test_cases); + ret = run_test_cases(kprobe_thumb32_test_cases, + kprobe_decode_thumb32_table); if (ret) goto out; #endif |