3.16.61-rc1 review patch. If anyone has any objections, please let me know.
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From: Michael Ellerman mpe@ellerman.id.au
commit cad0e39023b43d94d5e38dfd55c103e15bdd093d upstream.
The code patching code has always been a bit confused about whether it's best to use void *, unsigned int *, char *, etc. to point to instructions. In fact in the feature fixups tests we use both unsigned int[] and u8[] in different places.
Unfortunately the tests that use unsigned int[] calculate the size of the code blocks using subtraction of those unsigned int pointers, and then pass the result to memcmp(). This means we're only comparing 1/4 of the bytes we need to, because we need to multiply by sizeof(unsigned int) to get the number of *bytes*.
The result is that the tests do all the patching and then only compare some of the resulting code, so patching bugs that only effect that last 3/4 of the code could slip through undetected. It turns out that hasn't been happening, although one test had a bad expected case (see previous commit).
Fix it for now by multiplying the size by 4 in the affected functions.
Fixes: 362e7701fd18 ("powerpc: Add self-tests of the feature fixup code") Epic-brown-paper-bag-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Ben Hutchings ben@decadent.org.uk --- arch/powerpc/lib/feature-fixups.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
--- a/arch/powerpc/lib/feature-fixups.c +++ b/arch/powerpc/lib/feature-fixups.c @@ -170,7 +170,7 @@ void test_basic_patching(void) extern unsigned int end_ftr_fixup_test1[]; extern unsigned int ftr_fixup_test1_orig[]; extern unsigned int ftr_fixup_test1_expected[]; - int size = end_ftr_fixup_test1 - ftr_fixup_test1; + int size = 4 * (end_ftr_fixup_test1 - ftr_fixup_test1);
fixup.value = fixup.mask = 8; fixup.start_off = calc_offset(&fixup, ftr_fixup_test1 + 1); @@ -202,7 +202,7 @@ static void test_alternative_patching(vo extern unsigned int ftr_fixup_test2_orig[]; extern unsigned int ftr_fixup_test2_alt[]; extern unsigned int ftr_fixup_test2_expected[]; - int size = end_ftr_fixup_test2 - ftr_fixup_test2; + int size = 4 * (end_ftr_fixup_test2 - ftr_fixup_test2);
fixup.value = fixup.mask = 0xF; fixup.start_off = calc_offset(&fixup, ftr_fixup_test2 + 1); @@ -234,7 +234,7 @@ static void test_alternative_case_too_bi extern unsigned int end_ftr_fixup_test3[]; extern unsigned int ftr_fixup_test3_orig[]; extern unsigned int ftr_fixup_test3_alt[]; - int size = end_ftr_fixup_test3 - ftr_fixup_test3; + int size = 4 * (end_ftr_fixup_test3 - ftr_fixup_test3);
fixup.value = fixup.mask = 0xC; fixup.start_off = calc_offset(&fixup, ftr_fixup_test3 + 1); @@ -261,7 +261,7 @@ static void test_alternative_case_too_sm extern unsigned int ftr_fixup_test4_orig[]; extern unsigned int ftr_fixup_test4_alt[]; extern unsigned int ftr_fixup_test4_expected[]; - int size = end_ftr_fixup_test4 - ftr_fixup_test4; + int size = 4 * (end_ftr_fixup_test4 - ftr_fixup_test4); unsigned long flag;
/* Check a high-bit flag */ @@ -295,7 +295,7 @@ static void test_alternative_case_with_b extern unsigned int ftr_fixup_test5[]; extern unsigned int end_ftr_fixup_test5[]; extern unsigned int ftr_fixup_test5_expected[]; - int size = end_ftr_fixup_test5 - ftr_fixup_test5; + int size = 4 * (end_ftr_fixup_test5 - ftr_fixup_test5);
check(memcmp(ftr_fixup_test5, ftr_fixup_test5_expected, size) == 0); } @@ -305,7 +305,7 @@ static void test_alternative_case_with_e extern unsigned int ftr_fixup_test6[]; extern unsigned int end_ftr_fixup_test6[]; extern unsigned int ftr_fixup_test6_expected[]; - int size = end_ftr_fixup_test6 - ftr_fixup_test6; + int size = 4 * (end_ftr_fixup_test6 - ftr_fixup_test6);
check(memcmp(ftr_fixup_test6, ftr_fixup_test6_expected, size) == 0); }