Re: [PATCH] x86/tools/relocs: fix big section header tables
On Thu, Nov 29, 2018 at 04:22:00PM +0100, Artem Savkov wrote: > On Thu, Nov 29, 2018 at 08:23:12AM -0600, Josh Poimboeuf wrote: > > On Thu, Nov 29, 2018 at 02:51:33PM +0100, Artem Savkov wrote: > > > In case when the number of entries in the section header table is larger > > > then or equal to SHN_LORESERVE the size of the table is held in the > > > sh_size > > > member of the initial entry in section header table instead of e_shnum. > > > Same with the string table index which is located in sh_link instead of > > > e_shstrndx. > > > > > > This case is easily reproducible with KCFLAGS="-ffunction-sections", > > > bzImage build fails with "String table index out of bounds" error. > > > > > > Signed-off-by: Artem Savkov > > > --- > > > arch/x86/tools/relocs.c | 58 + > > > 1 file changed, 41 insertions(+), 17 deletions(-) > > > > > > diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c > > > index b629f6992d9f..5275ea0a0d13 100644 > > > --- a/arch/x86/tools/relocs.c > > > +++ b/arch/x86/tools/relocs.c > > > @@ -11,7 +11,9 @@ > > > #define Elf_Shdr ElfW(Shdr) > > > #define Elf_Sym ElfW(Sym) > > > > > > -static Elf_Ehdr ehdr; > > > +static Elf_Ehdr ehdr; > > > > I think there's a tab missing here, it doesn't line up with the other > > variables. > > This seems to be a vim bug. It aligns perfectly in > cat/less/lore.kernel.org which all seem to use tabstop=8 by default, but > it does not align in vim, but it does align with tabstop=7 in vim. Are you looking at the patch? Or the file itself? "less arch/x86/tools/relocs.c" shows the same issue. -- Josh
Re: [PATCH] x86/tools/relocs: fix big section header tables
On Thu, Nov 29, 2018 at 04:22:00PM +0100, Artem Savkov wrote: > On Thu, Nov 29, 2018 at 08:23:12AM -0600, Josh Poimboeuf wrote: > > On Thu, Nov 29, 2018 at 02:51:33PM +0100, Artem Savkov wrote: > > > In case when the number of entries in the section header table is larger > > > then or equal to SHN_LORESERVE the size of the table is held in the > > > sh_size > > > member of the initial entry in section header table instead of e_shnum. > > > Same with the string table index which is located in sh_link instead of > > > e_shstrndx. > > > > > > This case is easily reproducible with KCFLAGS="-ffunction-sections", > > > bzImage build fails with "String table index out of bounds" error. > > > > > > Signed-off-by: Artem Savkov > > > --- > > > arch/x86/tools/relocs.c | 58 + > > > 1 file changed, 41 insertions(+), 17 deletions(-) > > > > > > diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c > > > index b629f6992d9f..5275ea0a0d13 100644 > > > --- a/arch/x86/tools/relocs.c > > > +++ b/arch/x86/tools/relocs.c > > > @@ -11,7 +11,9 @@ > > > #define Elf_Shdr ElfW(Shdr) > > > #define Elf_Sym ElfW(Sym) > > > > > > -static Elf_Ehdr ehdr; > > > +static Elf_Ehdr ehdr; > > > > I think there's a tab missing here, it doesn't line up with the other > > variables. > > This seems to be a vim bug. It aligns perfectly in > cat/less/lore.kernel.org which all seem to use tabstop=8 by default, but > it does not align in vim, but it does align with tabstop=7 in vim. Are you looking at the patch? Or the file itself? "less arch/x86/tools/relocs.c" shows the same issue. -- Josh
Re: [PATCH] x86/tools/relocs: fix big section header tables
On Thu, Nov 29, 2018 at 08:23:12AM -0600, Josh Poimboeuf wrote: > On Thu, Nov 29, 2018 at 02:51:33PM +0100, Artem Savkov wrote: > > In case when the number of entries in the section header table is larger > > then or equal to SHN_LORESERVE the size of the table is held in the sh_size > > member of the initial entry in section header table instead of e_shnum. > > Same with the string table index which is located in sh_link instead of > > e_shstrndx. > > > > This case is easily reproducible with KCFLAGS="-ffunction-sections", > > bzImage build fails with "String table index out of bounds" error. > > > > Signed-off-by: Artem Savkov > > --- > > arch/x86/tools/relocs.c | 58 + > > 1 file changed, 41 insertions(+), 17 deletions(-) > > > > diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c > > index b629f6992d9f..5275ea0a0d13 100644 > > --- a/arch/x86/tools/relocs.c > > +++ b/arch/x86/tools/relocs.c > > @@ -11,7 +11,9 @@ > > #define Elf_Shdr ElfW(Shdr) > > #define Elf_SymElfW(Sym) > > > > -static Elf_Ehdr ehdr; > > +static Elf_Ehdrehdr; > > I think there's a tab missing here, it doesn't line up with the other > variables. This seems to be a vim bug. It aligns perfectly in cat/less/lore.kernel.org which all seem to use tabstop=8 by default, but it does not align in vim, but it does align with tabstop=7 in vim. -- Artem
Re: [PATCH] x86/tools/relocs: fix big section header tables
On Thu, Nov 29, 2018 at 08:23:12AM -0600, Josh Poimboeuf wrote: > On Thu, Nov 29, 2018 at 02:51:33PM +0100, Artem Savkov wrote: > > In case when the number of entries in the section header table is larger > > then or equal to SHN_LORESERVE the size of the table is held in the sh_size > > member of the initial entry in section header table instead of e_shnum. > > Same with the string table index which is located in sh_link instead of > > e_shstrndx. > > > > This case is easily reproducible with KCFLAGS="-ffunction-sections", > > bzImage build fails with "String table index out of bounds" error. > > > > Signed-off-by: Artem Savkov > > --- > > arch/x86/tools/relocs.c | 58 + > > 1 file changed, 41 insertions(+), 17 deletions(-) > > > > diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c > > index b629f6992d9f..5275ea0a0d13 100644 > > --- a/arch/x86/tools/relocs.c > > +++ b/arch/x86/tools/relocs.c > > @@ -11,7 +11,9 @@ > > #define Elf_Shdr ElfW(Shdr) > > #define Elf_SymElfW(Sym) > > > > -static Elf_Ehdr ehdr; > > +static Elf_Ehdrehdr; > > I think there's a tab missing here, it doesn't line up with the other > variables. This seems to be a vim bug. It aligns perfectly in cat/less/lore.kernel.org which all seem to use tabstop=8 by default, but it does not align in vim, but it does align with tabstop=7 in vim. -- Artem
Re: [PATCH] x86/tools/relocs: fix big section header tables
On Thu, Nov 29, 2018 at 02:51:33PM +0100, Artem Savkov wrote: > In case when the number of entries in the section header table is larger > then or equal to SHN_LORESERVE the size of the table is held in the sh_size > member of the initial entry in section header table instead of e_shnum. > Same with the string table index which is located in sh_link instead of > e_shstrndx. > > This case is easily reproducible with KCFLAGS="-ffunction-sections", > bzImage build fails with "String table index out of bounds" error. > > Signed-off-by: Artem Savkov > --- > arch/x86/tools/relocs.c | 58 + > 1 file changed, 41 insertions(+), 17 deletions(-) > > diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c > index b629f6992d9f..5275ea0a0d13 100644 > --- a/arch/x86/tools/relocs.c > +++ b/arch/x86/tools/relocs.c > @@ -11,7 +11,9 @@ > #define Elf_Shdr ElfW(Shdr) > #define Elf_Sym ElfW(Sym) > > -static Elf_Ehdr ehdr; > +static Elf_Ehdr ehdr; I think there's a tab missing here, it doesn't line up with the other variables. > +static unsigned long shnum; > +static unsigned int shstrndx; Otherwise the patch looks good to me. Reviewed-by: Josh Poimboeuf -- Josh
Re: [PATCH] x86/tools/relocs: fix big section header tables
On Thu, Nov 29, 2018 at 02:51:33PM +0100, Artem Savkov wrote: > In case when the number of entries in the section header table is larger > then or equal to SHN_LORESERVE the size of the table is held in the sh_size > member of the initial entry in section header table instead of e_shnum. > Same with the string table index which is located in sh_link instead of > e_shstrndx. > > This case is easily reproducible with KCFLAGS="-ffunction-sections", > bzImage build fails with "String table index out of bounds" error. > > Signed-off-by: Artem Savkov > --- > arch/x86/tools/relocs.c | 58 + > 1 file changed, 41 insertions(+), 17 deletions(-) > > diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c > index b629f6992d9f..5275ea0a0d13 100644 > --- a/arch/x86/tools/relocs.c > +++ b/arch/x86/tools/relocs.c > @@ -11,7 +11,9 @@ > #define Elf_Shdr ElfW(Shdr) > #define Elf_Sym ElfW(Sym) > > -static Elf_Ehdr ehdr; > +static Elf_Ehdr ehdr; I think there's a tab missing here, it doesn't line up with the other variables. > +static unsigned long shnum; > +static unsigned int shstrndx; Otherwise the patch looks good to me. Reviewed-by: Josh Poimboeuf -- Josh
[PATCH] x86/tools/relocs: fix big section header tables
In case when the number of entries in the section header table is larger
then or equal to SHN_LORESERVE the size of the table is held in the sh_size
member of the initial entry in section header table instead of e_shnum.
Same with the string table index which is located in sh_link instead of
e_shstrndx.
This case is easily reproducible with KCFLAGS="-ffunction-sections",
bzImage build fails with "String table index out of bounds" error.
Signed-off-by: Artem Savkov
---
arch/x86/tools/relocs.c | 58 +
1 file changed, 41 insertions(+), 17 deletions(-)
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index b629f6992d9f..5275ea0a0d13 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -11,7 +11,9 @@
#define Elf_Shdr ElfW(Shdr)
#define Elf_SymElfW(Sym)
-static Elf_Ehdr ehdr;
+static Elf_Ehdrehdr;
+static unsigned long shnum;
+static unsigned intshstrndx;
struct relocs {
uint32_t*offset;
@@ -241,9 +243,9 @@ static const char *sec_name(unsigned shndx)
{
const char *sec_strtab;
const char *name;
- sec_strtab = secs[ehdr.e_shstrndx].strtab;
+ sec_strtab = secs[shstrndx].strtab;
name = "";
- if (shndx < ehdr.e_shnum) {
+ if (shndx < shnum) {
name = sec_strtab + secs[shndx].shdr.sh_name;
}
else if (shndx == SHN_ABS) {
@@ -271,7 +273,7 @@ static const char *sym_name(const char *sym_strtab, Elf_Sym
*sym)
static Elf_Sym *sym_lookup(const char *symname)
{
int i;
- for (i = 0; i < ehdr.e_shnum; i++) {
+ for (i = 0; i < shnum; i++) {
struct section *sec = [i];
long nsyms;
char *strtab;
@@ -366,6 +368,9 @@ static void read_ehdr(FILE *fp)
ehdr.e_shnum = elf_half_to_cpu(ehdr.e_shnum);
ehdr.e_shstrndx = elf_half_to_cpu(ehdr.e_shstrndx);
+ shnum = ehdr.e_shnum;
+ shstrndx = ehdr.e_shstrndx;
+
if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) {
die("Unsupported ELF header type\n");
}
@@ -384,7 +389,26 @@ static void read_ehdr(FILE *fp)
if (ehdr.e_shentsize != sizeof(Elf_Shdr)) {
die("Bad section header entry\n");
}
- if (ehdr.e_shstrndx >= ehdr.e_shnum) {
+
+ if (shnum == SHN_UNDEF || shstrndx == SHN_XINDEX) {
+ Elf_Shdr shdr;
+
+ if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0)
+ die("Seek to %d failed: %s\n",
+ ehdr.e_shoff, strerror(errno));
+
+ if (fread(, sizeof(shdr), 1, fp) != 1)
+ die("Cannot read initial ELF section header: %s\n",
+ strerror(errno));
+
+ if (shnum == SHN_UNDEF)
+ shnum = elf_xword_to_cpu(shdr.sh_size);
+
+ if (shstrndx == SHN_XINDEX)
+ shstrndx = elf_word_to_cpu(shdr.sh_link);
+ }
+
+ if (shstrndx >= shnum) {
die("String table index out of bounds\n");
}
}
@@ -394,20 +418,20 @@ static void read_shdrs(FILE *fp)
int i;
Elf_Shdr shdr;
- secs = calloc(ehdr.e_shnum, sizeof(struct section));
+ secs = calloc(shnum, sizeof(struct section));
if (!secs) {
die("Unable to allocate %d section headers\n",
- ehdr.e_shnum);
+ shnum);
}
if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) {
die("Seek to %d failed: %s\n",
ehdr.e_shoff, strerror(errno));
}
- for (i = 0; i < ehdr.e_shnum; i++) {
+ for (i = 0; i < shnum; i++) {
struct section *sec = [i];
if (fread(, sizeof(shdr), 1, fp) != 1)
die("Cannot read ELF section headers %d/%d: %s\n",
- i, ehdr.e_shnum, strerror(errno));
+ i, shnum, strerror(errno));
sec->shdr.sh_name = elf_word_to_cpu(shdr.sh_name);
sec->shdr.sh_type = elf_word_to_cpu(shdr.sh_type);
sec->shdr.sh_flags = elf_xword_to_cpu(shdr.sh_flags);
@@ -418,7 +442,7 @@ static void read_shdrs(FILE *fp)
sec->shdr.sh_info = elf_word_to_cpu(shdr.sh_info);
sec->shdr.sh_addralign = elf_xword_to_cpu(shdr.sh_addralign);
sec->shdr.sh_entsize = elf_xword_to_cpu(shdr.sh_entsize);
- if (sec->shdr.sh_link < ehdr.e_shnum)
+ if (sec->shdr.sh_link < shnum)
sec->link = [sec->shdr.sh_link];
}
@@ -427,7 +451,7 @@ static void read_shdrs(FILE *fp)
static void read_strtabs(FILE *fp)
{
int i;
- for (i = 0; i < ehdr.e_shnum; i++) {
+ for (i = 0; i < shnum; i++) {
struct section *sec = [i];
if
[PATCH] x86/tools/relocs: fix big section header tables
In case when the number of entries in the section header table is larger
then or equal to SHN_LORESERVE the size of the table is held in the sh_size
member of the initial entry in section header table instead of e_shnum.
Same with the string table index which is located in sh_link instead of
e_shstrndx.
This case is easily reproducible with KCFLAGS="-ffunction-sections",
bzImage build fails with "String table index out of bounds" error.
Signed-off-by: Artem Savkov
---
arch/x86/tools/relocs.c | 58 +
1 file changed, 41 insertions(+), 17 deletions(-)
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index b629f6992d9f..5275ea0a0d13 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -11,7 +11,9 @@
#define Elf_Shdr ElfW(Shdr)
#define Elf_SymElfW(Sym)
-static Elf_Ehdr ehdr;
+static Elf_Ehdrehdr;
+static unsigned long shnum;
+static unsigned intshstrndx;
struct relocs {
uint32_t*offset;
@@ -241,9 +243,9 @@ static const char *sec_name(unsigned shndx)
{
const char *sec_strtab;
const char *name;
- sec_strtab = secs[ehdr.e_shstrndx].strtab;
+ sec_strtab = secs[shstrndx].strtab;
name = "";
- if (shndx < ehdr.e_shnum) {
+ if (shndx < shnum) {
name = sec_strtab + secs[shndx].shdr.sh_name;
}
else if (shndx == SHN_ABS) {
@@ -271,7 +273,7 @@ static const char *sym_name(const char *sym_strtab, Elf_Sym
*sym)
static Elf_Sym *sym_lookup(const char *symname)
{
int i;
- for (i = 0; i < ehdr.e_shnum; i++) {
+ for (i = 0; i < shnum; i++) {
struct section *sec = [i];
long nsyms;
char *strtab;
@@ -366,6 +368,9 @@ static void read_ehdr(FILE *fp)
ehdr.e_shnum = elf_half_to_cpu(ehdr.e_shnum);
ehdr.e_shstrndx = elf_half_to_cpu(ehdr.e_shstrndx);
+ shnum = ehdr.e_shnum;
+ shstrndx = ehdr.e_shstrndx;
+
if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) {
die("Unsupported ELF header type\n");
}
@@ -384,7 +389,26 @@ static void read_ehdr(FILE *fp)
if (ehdr.e_shentsize != sizeof(Elf_Shdr)) {
die("Bad section header entry\n");
}
- if (ehdr.e_shstrndx >= ehdr.e_shnum) {
+
+ if (shnum == SHN_UNDEF || shstrndx == SHN_XINDEX) {
+ Elf_Shdr shdr;
+
+ if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0)
+ die("Seek to %d failed: %s\n",
+ ehdr.e_shoff, strerror(errno));
+
+ if (fread(, sizeof(shdr), 1, fp) != 1)
+ die("Cannot read initial ELF section header: %s\n",
+ strerror(errno));
+
+ if (shnum == SHN_UNDEF)
+ shnum = elf_xword_to_cpu(shdr.sh_size);
+
+ if (shstrndx == SHN_XINDEX)
+ shstrndx = elf_word_to_cpu(shdr.sh_link);
+ }
+
+ if (shstrndx >= shnum) {
die("String table index out of bounds\n");
}
}
@@ -394,20 +418,20 @@ static void read_shdrs(FILE *fp)
int i;
Elf_Shdr shdr;
- secs = calloc(ehdr.e_shnum, sizeof(struct section));
+ secs = calloc(shnum, sizeof(struct section));
if (!secs) {
die("Unable to allocate %d section headers\n",
- ehdr.e_shnum);
+ shnum);
}
if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) {
die("Seek to %d failed: %s\n",
ehdr.e_shoff, strerror(errno));
}
- for (i = 0; i < ehdr.e_shnum; i++) {
+ for (i = 0; i < shnum; i++) {
struct section *sec = [i];
if (fread(, sizeof(shdr), 1, fp) != 1)
die("Cannot read ELF section headers %d/%d: %s\n",
- i, ehdr.e_shnum, strerror(errno));
+ i, shnum, strerror(errno));
sec->shdr.sh_name = elf_word_to_cpu(shdr.sh_name);
sec->shdr.sh_type = elf_word_to_cpu(shdr.sh_type);
sec->shdr.sh_flags = elf_xword_to_cpu(shdr.sh_flags);
@@ -418,7 +442,7 @@ static void read_shdrs(FILE *fp)
sec->shdr.sh_info = elf_word_to_cpu(shdr.sh_info);
sec->shdr.sh_addralign = elf_xword_to_cpu(shdr.sh_addralign);
sec->shdr.sh_entsize = elf_xword_to_cpu(shdr.sh_entsize);
- if (sec->shdr.sh_link < ehdr.e_shnum)
+ if (sec->shdr.sh_link < shnum)
sec->link = [sec->shdr.sh_link];
}
@@ -427,7 +451,7 @@ static void read_shdrs(FILE *fp)
static void read_strtabs(FILE *fp)
{
int i;
- for (i = 0; i < ehdr.e_shnum; i++) {
+ for (i = 0; i < shnum; i++) {
struct section *sec = [i];
if
