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author | Breno Rodrigues Guimaraes <brenorg@gmail.com> | 2023-02-20 18:22:17 -0300 |
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committer | Breno Rodrigues Guimaraes <brenorg@gmail.com> | 2023-02-24 20:39:11 -0300 |
commit | de3e1f5e11f533d8678474eb9234ba35efa960d6 (patch) | |
tree | 276fecc1cba3f3543d241ea34115f6ef4030733c | |
parent | 69a7ae54d27513d7553b4d8bd77ade017e674e22 (diff) | |
download | patchelf-de3e1f5e11f533d8678474eb9234ba35efa960d6.tar.gz |
Add one extra page to avoid overlapping with next page if its rounded down
-rw-r--r-- | src/patchelf.cc | 4 | ||||
-rw-r--r-- | tests/Makefile.am | 4 | ||||
-rwxr-xr-x | tests/overlapping-segments-after-rounding | bin | 0 -> 227896 bytes | |||
-rwxr-xr-x | tests/overlapping-segments-after-rounding.sh | 23 |
4 files changed, 29 insertions, 2 deletions
diff --git a/src/patchelf.cc b/src/patchelf.cc index ca247c1..b78210c 100644 --- a/src/patchelf.cc +++ b/src/patchelf.cc @@ -985,7 +985,9 @@ void ElfFile<ElfFileParamNames>::rewriteSectionsExecutable() /* Calculate how many bytes are needed out of the additional pages. */ size_t extraSpace = neededSpace - startOffset; - unsigned int neededPages = roundUp(extraSpace, getPageSize()) / getPageSize(); + // Always give one extra page to avoid colliding with segments that start at + // unaligned addresses and will be rounded down when loaded + unsigned int neededPages = 1 + roundUp(extraSpace, getPageSize()) / getPageSize(); debug("needed pages is %d\n", neededPages); if (neededPages * getPageSize() > firstPage) error("virtual address space underrun!"); diff --git a/tests/Makefile.am b/tests/Makefile.am index 4a08c14..b3f0b97 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -47,6 +47,7 @@ src_TESTS = \ print-execstack.sh \ modify-execstack.sh \ rename-dynamic-symbols.sh \ + overlapping-segments-after-rounding.sh \ empty-note.sh build_TESTS = \ @@ -54,7 +55,8 @@ build_TESTS = \ TESTS = $(src_TESTS) $(build_TESTS) -EXTRA_DIST = no-rpath-prebuild $(src_TESTS) no-rpath-prebuild.sh invalid-elf endianness empty-note +EXTRA_DIST = no-rpath-prebuild $(src_TESTS) no-rpath-prebuild.sh invalid-elf endianness empty-note \ + overlapping-segments-after-rounding TESTS_ENVIRONMENT = PATCHELF_DEBUG=1 STRIP=$(STRIP) OBJDUMP=$(OBJDUMP) READELF=$(READELF) OBJCOPY=$(OBJCOPY) diff --git a/tests/overlapping-segments-after-rounding b/tests/overlapping-segments-after-rounding Binary files differnew file mode 100755 index 0000000..ecad537 --- /dev/null +++ b/tests/overlapping-segments-after-rounding diff --git a/tests/overlapping-segments-after-rounding.sh b/tests/overlapping-segments-after-rounding.sh new file mode 100755 index 0000000..d7c87b1 --- /dev/null +++ b/tests/overlapping-segments-after-rounding.sh @@ -0,0 +1,23 @@ +#! /bin/sh -e + +PATCHELF=$(readlink -f "../src/patchelf") +SCRATCH="scratch/$(basename "$0" .sh)" +READELF=${READELF:-readelf} + +EXEC_NAME="overlapping-segments-after-rounding" + +if test "$(uname -i)" = x86_64 && test "$(uname)" = Linux; then + rm -rf "${SCRATCH}" + mkdir -p "${SCRATCH}" + + cp "${srcdir}/${EXEC_NAME}" "${SCRATCH}/" + cd "${SCRATCH}" + + ${PATCHELF} --force-rpath --remove-rpath --output modified1 "${EXEC_NAME}" + + ldd modified1 + + ${PATCHELF} --force-rpath --set-rpath "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" --output modified2 modified1 + + ldd modified2 +fi |