From 70320991e18e499b464f4d5066acdfc6a638d316 Mon Sep 17 00:00:00 2001 From: Chris Kennelly Date: Thu, 13 May 2021 16:02:10 +0800 Subject: [PATCH] tools/testing/selftests: add self-test for verifying load alignment mainline inclusion from mainline-5.10-rc1 commit 206e22f01941b19f9466f48b53cc0d19de493e7a category: bugfix bugzilla: 51854 CVE: NA ------------------------------------------------- This produces a PIE binary with a variety of p_align requirements, suitable for verifying that the load address meets that alignment requirement. Signed-off-by: Chris Kennelly Signed-off-by: Andrew Morton Cc: Shuah Khan Cc: Alexander Viro Cc: Alexey Dobriyan Cc: David Rientjes Cc: Fangrui Song Cc: Hugh Dickens Cc: Ian Rogers Cc: "Kirill A. Shutemov" Cc: Mike Kravetz Cc: Nick Desaulniers Cc: Sandeep Patil Cc: Song Liu Cc: Suren Baghdasaryan Link: https://lkml.kernel.org/r/20200820170541.1132271-3-ckennelly@google.com Link: https://lkml.kernel.org/r/20200821233848.3904680-3-ckennelly@google.com Signed-off-by: Linus Torvalds Conflicts: tools/testing/selftests/exec/.gitignore tools/testing/selftests/exec/Makefile Signed-off-by: Yang Yingliang Reviewed-by: Zhang Yi Signed-off-by: Yang Yingliang --- tools/testing/selftests/exec/.gitignore | 3 +- tools/testing/selftests/exec/Makefile | 9 ++- tools/testing/selftests/exec/load_address.c | 68 +++++++++++++++++++++ 3 files changed, 77 insertions(+), 3 deletions(-) create mode 100644 tools/testing/selftests/exec/load_address.c diff --git a/tools/testing/selftests/exec/.gitignore b/tools/testing/selftests/exec/.gitignore index 64073e050c6a..4561cd548175 100644 --- a/tools/testing/selftests/exec/.gitignore +++ b/tools/testing/selftests/exec/.gitignore @@ -6,4 +6,5 @@ execveat.moved execveat.path.ephemeral execveat.ephemeral execveat.denatured -xxxxxxxx* \ No newline at end of file +/load_address_* +xxxxxxxx* diff --git a/tools/testing/selftests/exec/Makefile b/tools/testing/selftests/exec/Makefile index 427c41ba5151..6c6137b1af8d 100644 --- a/tools/testing/selftests/exec/Makefile +++ b/tools/testing/selftests/exec/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 CFLAGS = -Wall -TEST_GEN_PROGS := execveat +TEST_GEN_PROGS := execveat load_address_4096 load_address_2097152 load_address_16777216 TEST_GEN_FILES := execveat.symlink execveat.denatured script subdir # Makefile is a run-time dependency, since it's accessed by the execveat test TEST_FILES := Makefile @@ -21,4 +21,9 @@ $(OUTPUT)/execveat.symlink: $(OUTPUT)/execveat $(OUTPUT)/execveat.denatured: $(OUTPUT)/execveat cp $< $@ chmod -x $@ - +$(OUTPUT)/load_address_4096: load_address.c + $(CC) $(CFLAGS) $(LDFLAGS) -Wl,-z,max-page-size=0x1000 -pie $< -o $@ +$(OUTPUT)/load_address_2097152: load_address.c + $(CC) $(CFLAGS) $(LDFLAGS) -Wl,-z,max-page-size=0x200000 -pie $< -o $@ +$(OUTPUT)/load_address_16777216: load_address.c + $(CC) $(CFLAGS) $(LDFLAGS) -Wl,-z,max-page-size=0x1000000 -pie $< -o $@ diff --git a/tools/testing/selftests/exec/load_address.c b/tools/testing/selftests/exec/load_address.c new file mode 100644 index 000000000000..d487c2f6a615 --- /dev/null +++ b/tools/testing/selftests/exec/load_address.c @@ -0,0 +1,68 @@ +// SPDX-License-Identifier: GPL-2.0-only +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif +#include +#include +#include + +struct Statistics { + unsigned long long load_address; + unsigned long long alignment; +}; + +int ExtractStatistics(struct dl_phdr_info *info, size_t size, void *data) +{ + struct Statistics *stats = (struct Statistics *) data; + int i; + + if (info->dlpi_name != NULL && info->dlpi_name[0] != '\0') { + // Ignore headers from other than the executable. + return 2; + } + + stats->load_address = (unsigned long long) info->dlpi_addr; + stats->alignment = 0; + + for (i = 0; i < info->dlpi_phnum; i++) { + if (info->dlpi_phdr[i].p_type != PT_LOAD) + continue; + + if (info->dlpi_phdr[i].p_align > stats->alignment) + stats->alignment = info->dlpi_phdr[i].p_align; + } + + return 1; // Terminate dl_iterate_phdr. +} + +int main(int argc, char **argv) +{ + struct Statistics extracted; + unsigned long long misalign; + int ret; + + ret = dl_iterate_phdr(ExtractStatistics, &extracted); + if (ret != 1) { + fprintf(stderr, "FAILED\n"); + return 1; + } + + if (extracted.alignment == 0) { + fprintf(stderr, "No alignment found\n"); + return 1; + } else if (extracted.alignment & (extracted.alignment - 1)) { + fprintf(stderr, "Alignment is not a power of 2\n"); + return 1; + } + + misalign = extracted.load_address & (extracted.alignment - 1); + if (misalign) { + printf("alignment = %llu, load_address = %llu\n", + extracted.alignment, extracted.load_address); + fprintf(stderr, "FAILED\n"); + return 1; + } + + fprintf(stderr, "PASS\n"); + return 0; +} -- GitLab