[build] Do not apply WORKAROUND_CFLAGS for host compiler

The WORKAROUND_CFLAGS list is constructed based on running tests on
the target compiler, and the results may not be valid for the host
compiler.

The only relevant workaround required for the host compiler is
-Wno-stringop-truncation, which is needed to avoid a spurious compiler
warning for a totally correct usage of strncpy() in util/elf2efi.c.

Duplicating the workaround tests for the host compiler is messy, as is
conditionally applying __attribute__((nonstring)).  Fix instead by
disapplying WORKAROUND_CFLAGS for the host compiler, and using
memcpy() with an explicitly calculated length instead of strncpy() in
util/elf2efi.c.

Reported-by: Ignat Korchagin <ignat@cloudflare.com>
Reported-by: Christopher Clark <christopher.w.clark@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/Makefile.housekeeping b/src/Makefile.housekeeping
index 4b09e81f0b1eb82e79f6af11986d64bf907a5069..1b175b9508c0d20f169801f8763d12566e6848c4 100644 (file)
--- a/src/Makefile.housekeeping
+++ b/src/Makefile.housekeeping
@@ -454,7 +454,7 @@ endif
 CFLAGS         += $(WORKAROUND_CFLAGS) $(EXTRA_CFLAGS)
 ASFLAGS                += $(WORKAROUND_ASFLAGS) $(EXTRA_ASFLAGS)
 LDFLAGS                += $(WORKAROUND_LDFLAGS) $(EXTRA_LDFLAGS)
-HOST_CFLAGS    += $(WORKAROUND_CFLAGS) -O2 -g
+HOST_CFLAGS    += -O2 -g
 
 # Inhibit -Werror if NO_WERROR is specified on make command line
 #

diff --git a/src/util/elf2efi.c b/src/util/elf2efi.c
index 2c5b9df8aae853bfce4d5d3bae89dfea1ac5dec1..bcd53c9afda7880d42ec80c07f170edd4eae89c2 100644 (file)
--- a/src/util/elf2efi.c
+++ b/src/util/elf2efi.c
@@ -458,6 +458,7 @@ static struct pe_section * process_section ( struct elf_file *elf,
                                             struct pe_header *pe_header ) {
        struct pe_section *new;
        const char *name;
+       size_t name_len;
        size_t section_memsz;
        size_t section_filesz;
        unsigned long code_start;
@@ -494,7 +495,10 @@ static struct pe_section * process_section ( struct elf_file *elf,
        memset ( new, 0, sizeof ( *new ) + section_filesz );
 
        /* Fill in section header details */
-       strncpy ( ( char * ) new->hdr.Name, name, sizeof ( new->hdr.Name ) );
+       name_len = strlen ( name );
+       if ( name_len > sizeof ( new->hdr.Name ) )
+               name_len = sizeof ( new->hdr.Name );
+       memcpy ( new->hdr.Name, name, name_len );
        new->hdr.Misc.VirtualSize = section_memsz;
        new->hdr.VirtualAddress = shdr->sh_addr;
        new->hdr.SizeOfRawData = section_filesz;