bionic: fix assorted static analyzer warnings
Warnings:
bionic/libc/bionic/fts.c:722:5: warning: Null passed to a callee that
requires a non-null 1st parameter
bionic/libc/bionic/sched_cpualloc.c:34:25: warning: Result of 'malloc'
is converted to a pointer of type 'cpu_set_t', which is incompatible
with sizeof operand type 'unsigned long'
bionic/linker/linker_main.cpp:315:7: warning: Access to field 'e_type'
results in a dereference of a null pointer (loaded from variable
'elf_hdr')
bionic/linker/linker_main.cpp:493:66: warning: Access to field 'e_phoff'
results in a dereference of a null pointer (loaded from variable
'elf_hdr')
bionic/linker/linker_main.cpp:90:14: warning: Access to field 'next'
results in a dereference of a null pointer (loaded from variable 'prev')
Bug: None
Test: mma; analyzer warnings are gone. CtsBionicTestCases pass.
Change-Id: I699a60c2c6f64c50b9ea06848a680c98a8abb44a
diff --git a/linker/linker_main.cpp b/linker/linker_main.cpp
index 5dc215f..db36976 100644
--- a/linker/linker_main.cpp
+++ b/linker/linker_main.cpp
@@ -87,6 +87,7 @@
// prev will never be null, because the first entry in solist is
// always the static libdl_info.
+ CHECK(prev != nullptr);
prev->next = si->next;
if (si == sonext) {
sonext = prev;
@@ -307,6 +308,11 @@
break;
}
}
+
+ if (si->base == 0) {
+ async_safe_fatal("Could not find a PHDR: broken executable?");
+ }
+
si->dynamic = nullptr;
ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(si->base);
@@ -488,6 +494,15 @@
static uintptr_t linktime_addr = reinterpret_cast<uintptr_t>(&linktime_addr);
ElfW(Addr) linker_addr = reinterpret_cast<uintptr_t>(&linktime_addr) - linktime_addr;
+#if defined(__clang_analyzer__)
+ // The analyzer assumes that linker_addr will always be null. Make it an
+ // unknown value so we don't have to mark N places with NOLINTs.
+ //
+ // (`+=`, rather than `=`, allows us to sidestep a potential "unused store"
+ // complaint)
+ linker_addr += reinterpret_cast<uintptr_t>(raw_args);
+#endif
+
ElfW(Addr) entry_point = args.getauxval(AT_ENTRY);
ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(linker_addr);
ElfW(Phdr)* phdr = reinterpret_cast<ElfW(Phdr)*>(linker_addr + elf_hdr->e_phoff);