[PATCH 0/3] x86/vdso: Little clean-ups

[PATCH 0/3] x86/vdso: Little clean-ups

[Dmitry Safonov]

Resending some patches those weren't needed after timens series evolved,
but still make sense. Nothing really important, just 3 nits here and
there.

Cc: Andrei Vagin <avagin@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: x86@kernel.org

Dmitry Safonov (3):
  x86/vdso2c: Correct err messages on file opening
  x86/vdso2c: Convert iterators to unsigned
  x86/vdso/Makefile: Add vobjs32

 arch/x86/entry/vdso/Makefile | 15 +++++----------
 arch/x86/entry/vdso/vdso2c.c |  4 ++--
 arch/x86/entry/vdso/vdso2c.h | 16 +++++++---------
 3 files changed, 14 insertions(+), 21 deletions(-)

-- 
2.26.0

[PATCH 1/3] x86/vdso2c: Correct err messages on file opening

[Dmitry Safonov]

err() message in main() is misleading: it should print `outfilename`,
which is argv[3], not argv[2].

Correct error messages to be more precise about what failed and for
which file.

Co-developed-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
 arch/x86/entry/vdso/vdso2c.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/entry/vdso/vdso2c.c b/arch/x86/entry/vdso/vdso2c.c
index 3842873b3ae3..7380908045c7 100644
--- a/arch/x86/entry/vdso/vdso2c.c
+++ b/arch/x86/entry/vdso/vdso2c.c
@@ -187,7 +187,7 @@ static void map_input(const char *name, void **addr, size_t *len, int prot)
 
 	int fd = open(name, O_RDONLY);
 	if (fd == -1)
-		err(1, "%s", name);
+		err(1, "open(%s)", name);
 
 	tmp_len = lseek(fd, 0, SEEK_END);
 	if (tmp_len == (off_t)-1)
@@ -240,7 +240,7 @@ int main(int argc, char **argv)
 	outfilename = argv[3];
 	outfile = fopen(outfilename, "w");
 	if (!outfile)
-		err(1, "%s", argv[2]);
+		err(1, "fopen(%s)", outfilename);
 
 	go(raw_addr, raw_len, stripped_addr, stripped_len, outfile, name);
 
-- 
2.26.0

[tip: x86/vdso] x86/vdso/vdso2c: Correct error messages on file open

[tip-bot2 for Dmitry Safonov]

The following commit has been merged into the x86/vdso branch of tip:

Commit-ID:     089ef5579fc1b0b748bfb1600b4392f42db6fd5f
Gitweb:        https://git.kernel.org/tip/089ef5579fc1b0b748bfb1600b4392f42db6fd5f
Author:        Dmitry Safonov <dima@arista.com>
AuthorDate:    Mon, 20 Apr 2020 19:32:53 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Tue, 21 Apr 2020 20:33:16 +02:00

x86/vdso/vdso2c: Correct error messages on file open

err() message in main() is misleading: it should print `outfilename`,
which is argv[3], not argv[2].

Correct error messages to be more precise about what failed and for
which file.

Co-developed-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200420183256.660371-2-dima@arista.com

---
 arch/x86/entry/vdso/vdso2c.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/entry/vdso/vdso2c.c b/arch/x86/entry/vdso/vdso2c.c
index 3842873..7380908 100644
--- a/arch/x86/entry/vdso/vdso2c.c
+++ b/arch/x86/entry/vdso/vdso2c.c
@@ -187,7 +187,7 @@ static void map_input(const char *name, void **addr, size_t *len, int prot)
 
 	int fd = open(name, O_RDONLY);
 	if (fd == -1)
-		err(1, "%s", name);
+		err(1, "open(%s)", name);
 
 	tmp_len = lseek(fd, 0, SEEK_END);
 	if (tmp_len == (off_t)-1)
@@ -240,7 +240,7 @@ int main(int argc, char **argv)
 	outfilename = argv[3];
 	outfile = fopen(outfilename, "w");
 	if (!outfile)
-		err(1, "%s", argv[2]);
+		err(1, "fopen(%s)", outfilename);
 
 	go(raw_addr, raw_len, stripped_addr, stripped_len, outfile, name);
 

[PATCH 2/3] x86/vdso2c: Convert iterator to unsigned

[Dmitry Safonov]

i and j are used everywhere with unsigned types.
Cleanup and prettify the code a bit.

Introduce syms_nr for readability and as a preparation for allocating an
array of vDSO entries that will be needed for creating two vdso .so's:
one for host tasks and another for processes inside time namespace.

Co-developed-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
 arch/x86/entry/vdso/vdso2c.h | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/x86/entry/vdso/vdso2c.h b/arch/x86/entry/vdso/vdso2c.h
index a20b134de2a8..80be339ee93e 100644
--- a/arch/x86/entry/vdso/vdso2c.h
+++ b/arch/x86/entry/vdso/vdso2c.h
@@ -13,7 +13,7 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
 	unsigned long load_size = -1;  /* Work around bogus warning */
 	unsigned long mapping_size;
 	ELF(Ehdr) *hdr = (ELF(Ehdr) *)raw_addr;
-	int i;
+	unsigned int i, syms_nr;
 	unsigned long j;
 	ELF(Shdr) *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr,
 		*alt_sec = NULL;
@@ -86,11 +86,10 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
 	strtab_hdr = raw_addr + GET_LE(&hdr->e_shoff) +
 		GET_LE(&hdr->e_shentsize) * GET_LE(&symtab_hdr->sh_link);
 
+	syms_nr = GET_LE(&symtab_hdr->sh_size) / GET_LE(&symtab_hdr->sh_entsize);
 	/* Walk the symbol table */
-	for (i = 0;
-	     i < GET_LE(&symtab_hdr->sh_size) / GET_LE(&symtab_hdr->sh_entsize);
-	     i++) {
-		int k;
+	for (i = 0; i < syms_nr; i++) {
+		unsigned int k;
 		ELF(Sym) *sym = raw_addr + GET_LE(&symtab_hdr->sh_offset) +
 			GET_LE(&symtab_hdr->sh_entsize) * i;
 		const char *sym_name = raw_addr +
-- 
2.26.0

Re: [PATCH 2/3] x86/vdso2c: Convert iterator to unsigned

[Dmitry Safonov]

This one was sent by a mistake, see
> [PATCH 2/3] x86/vdso2c: Convert iterators to unsigned
instead, please.

On 4/20/20 7:32 PM, Dmitry Safonov wrote:
> i and j are used everywhere with unsigned types.
> Cleanup and prettify the code a bit.
> 
> Introduce syms_nr for readability and as a preparation for allocating an
> array of vDSO entries that will be needed for creating two vdso .so's:
> one for host tasks and another for processes inside time namespace.
> 
> Co-developed-by: Andrei Vagin <avagin@openvz.org>
> Signed-off-by: Andrei Vagin <avagin@openvz.org>
> Signed-off-by: Dmitry Safonov <dima@arista.com>
[..]
Thanks,
          Dmitry

[PATCH 2/3] x86/vdso2c: Convert iterators to unsigned

[Dmitry Safonov]

`i` and `j` are used everywhere with unsigned types.

Convert `i` to unsigned long in order to avoid signed to unsigned
comparisons.  Convert `k` to unsigned int with the same purpose.
Also, drop `j` as `i` could be used in place of it.
Introduce syms_nr for readability.

Co-developed-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
 arch/x86/entry/vdso/vdso2c.h | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/arch/x86/entry/vdso/vdso2c.h b/arch/x86/entry/vdso/vdso2c.h
index a20b134de2a8..6f46e11ce539 100644
--- a/arch/x86/entry/vdso/vdso2c.h
+++ b/arch/x86/entry/vdso/vdso2c.h
@@ -13,8 +13,7 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
 	unsigned long load_size = -1;  /* Work around bogus warning */
 	unsigned long mapping_size;
 	ELF(Ehdr) *hdr = (ELF(Ehdr) *)raw_addr;
-	int i;
-	unsigned long j;
+	unsigned long i, syms_nr;
 	ELF(Shdr) *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr,
 		*alt_sec = NULL;
 	ELF(Dyn) *dyn = 0, *dyn_end = 0;
@@ -86,11 +85,10 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
 	strtab_hdr = raw_addr + GET_LE(&hdr->e_shoff) +
 		GET_LE(&hdr->e_shentsize) * GET_LE(&symtab_hdr->sh_link);
 
+	syms_nr = GET_LE(&symtab_hdr->sh_size) / GET_LE(&symtab_hdr->sh_entsize);
 	/* Walk the symbol table */
-	for (i = 0;
-	     i < GET_LE(&symtab_hdr->sh_size) / GET_LE(&symtab_hdr->sh_entsize);
-	     i++) {
-		int k;
+	for (i = 0; i < syms_nr; i++) {
+		unsigned int k;
 		ELF(Sym) *sym = raw_addr + GET_LE(&symtab_hdr->sh_offset) +
 			GET_LE(&symtab_hdr->sh_entsize) * i;
 		const char *sym_name = raw_addr +
@@ -150,11 +148,11 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
 	fprintf(outfile,
 		"static unsigned char raw_data[%lu] __ro_after_init __aligned(PAGE_SIZE) = {",
 		mapping_size);
-	for (j = 0; j < stripped_len; j++) {
-		if (j % 10 == 0)
+	for (i = 0; i < stripped_len; i++) {
+		if (i % 10 == 0)
 			fprintf(outfile, "\n\t");
 		fprintf(outfile, "0x%02X, ",
-			(int)((unsigned char *)stripped_addr)[j]);
+			(int)((unsigned char *)stripped_addr)[i]);
 	}
 	fprintf(outfile, "\n};\n\n");
 
-- 
2.26.0

[tip: x86/vdso] x86/vdso/vdso2c: Convert iterators to unsigned

[tip-bot2 for Dmitry Safonov]

The following commit has been merged into the x86/vdso branch of tip:

Commit-ID:     833e55bb99bce116682efb94870b5c9f8a66f6af
Gitweb:        https://git.kernel.org/tip/833e55bb99bce116682efb94870b5c9f8a66f6af
Author:        Dmitry Safonov <dima@arista.com>
AuthorDate:    Mon, 20 Apr 2020 19:32:55 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Tue, 21 Apr 2020 20:33:16 +02:00

x86/vdso/vdso2c: Convert iterators to unsigned

`i` and `j` are used everywhere with unsigned types.

Convert `i` to unsigned long in order to avoid signed to unsigned
comparisons.  Convert `k` to unsigned int with the same purpose.
Also, drop `j` as `i` could be used in place of it.
Introduce syms_nr for readability.

Co-developed-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200420183256.660371-4-dima@arista.com

---
 arch/x86/entry/vdso/vdso2c.h | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/arch/x86/entry/vdso/vdso2c.h b/arch/x86/entry/vdso/vdso2c.h
index a20b134..6f46e11 100644
--- a/arch/x86/entry/vdso/vdso2c.h
+++ b/arch/x86/entry/vdso/vdso2c.h
@@ -13,8 +13,7 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
 	unsigned long load_size = -1;  /* Work around bogus warning */
 	unsigned long mapping_size;
 	ELF(Ehdr) *hdr = (ELF(Ehdr) *)raw_addr;
-	int i;
-	unsigned long j;
+	unsigned long i, syms_nr;
 	ELF(Shdr) *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr,
 		*alt_sec = NULL;
 	ELF(Dyn) *dyn = 0, *dyn_end = 0;
@@ -86,11 +85,10 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
 	strtab_hdr = raw_addr + GET_LE(&hdr->e_shoff) +
 		GET_LE(&hdr->e_shentsize) * GET_LE(&symtab_hdr->sh_link);
 
+	syms_nr = GET_LE(&symtab_hdr->sh_size) / GET_LE(&symtab_hdr->sh_entsize);
 	/* Walk the symbol table */
-	for (i = 0;
-	     i < GET_LE(&symtab_hdr->sh_size) / GET_LE(&symtab_hdr->sh_entsize);
-	     i++) {
-		int k;
+	for (i = 0; i < syms_nr; i++) {
+		unsigned int k;
 		ELF(Sym) *sym = raw_addr + GET_LE(&symtab_hdr->sh_offset) +
 			GET_LE(&symtab_hdr->sh_entsize) * i;
 		const char *sym_name = raw_addr +
@@ -150,11 +148,11 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
 	fprintf(outfile,
 		"static unsigned char raw_data[%lu] __ro_after_init __aligned(PAGE_SIZE) = {",
 		mapping_size);
-	for (j = 0; j < stripped_len; j++) {
-		if (j % 10 == 0)
+	for (i = 0; i < stripped_len; i++) {
+		if (i % 10 == 0)
 			fprintf(outfile, "\n\t");
 		fprintf(outfile, "0x%02X, ",
-			(int)((unsigned char *)stripped_addr)[j]);
+			(int)((unsigned char *)stripped_addr)[i]);
 	}
 	fprintf(outfile, "\n};\n\n");
 

[PATCH 3/3] x86/vdso/Makefile: Add vobjs32

[Dmitry Safonov]

Treat ia32/i386 objects in array the same as 64-bit vdso objects.

Co-developed-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
 arch/x86/entry/vdso/Makefile | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 433a1259f61d..54e03ab26ff3 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -24,6 +24,8 @@ VDSO32-$(CONFIG_IA32_EMULATION)	:= y
 
 # files to link into the vdso
 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
+vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
+vobjs32-y += vdso32/vclock_gettime.o
 
 # files to link into kernel
 obj-y				+= vma.o
@@ -37,10 +39,12 @@ vdso_img-$(VDSO32-y)		+= 32
 obj-$(VDSO32-y)			+= vdso32-setup.o
 
 vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
+vobjs32 := $(foreach F,$(vobjs32-y),$(obj)/$F)
 
 $(obj)/vdso.o: $(obj)/vdso.so
 
 targets += vdso.lds $(vobjs-y)
+targets += vdso32/vdso32.lds $(vobjs32-y)
 
 # Build the vDSO image C files and link them in.
 vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
@@ -130,10 +134,6 @@ $(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE
 CPPFLAGS_vdso32/vdso32.lds = $(CPPFLAGS_vdso.lds)
 VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1
 
-targets += vdso32/vdso32.lds
-targets += vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
-targets += vdso32/vclock_gettime.o
-
 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO
 $(obj)/vdso32.so.dbg: KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
 $(obj)/vdso32.so.dbg: asflags-$(CONFIG_X86_64) += -m32
@@ -158,12 +158,7 @@ endif
 
 $(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
 
-$(obj)/vdso32.so.dbg: FORCE \
-		      $(obj)/vdso32/vdso32.lds \
-		      $(obj)/vdso32/vclock_gettime.o \
-		      $(obj)/vdso32/note.o \
-		      $(obj)/vdso32/system_call.o \
-		      $(obj)/vdso32/sigreturn.o
+$(obj)/vdso32.so.dbg: $(obj)/vdso32/vdso32.lds $(vobjs32) FORCE
 	$(call if_changed,vdso_and_check)
 
 #
-- 
2.26.0

[tip: x86/vdso] x86/vdso/Makefile: Add vobjs32

[tip-bot2 for Dmitry Safonov]

The following commit has been merged into the x86/vdso branch of tip:

Commit-ID:     cd2f45b7514cdddabbf3f81a98a20ae02f99efa1
Gitweb:        https://git.kernel.org/tip/cd2f45b7514cdddabbf3f81a98a20ae02f99efa1
Author:        Dmitry Safonov <dima@arista.com>
AuthorDate:    Mon, 20 Apr 2020 19:32:56 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Tue, 21 Apr 2020 20:33:17 +02:00

x86/vdso/Makefile: Add vobjs32

Treat ia32/i386 objects in array the same as 64-bit vdso objects.

Co-developed-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200420183256.660371-5-dima@arista.com

---
 arch/x86/entry/vdso/Makefile | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 433a125..54e03ab 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -24,6 +24,8 @@ VDSO32-$(CONFIG_IA32_EMULATION)	:= y
 
 # files to link into the vdso
 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
+vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
+vobjs32-y += vdso32/vclock_gettime.o
 
 # files to link into kernel
 obj-y				+= vma.o
@@ -37,10 +39,12 @@ vdso_img-$(VDSO32-y)		+= 32
 obj-$(VDSO32-y)			+= vdso32-setup.o
 
 vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
+vobjs32 := $(foreach F,$(vobjs32-y),$(obj)/$F)
 
 $(obj)/vdso.o: $(obj)/vdso.so
 
 targets += vdso.lds $(vobjs-y)
+targets += vdso32/vdso32.lds $(vobjs32-y)
 
 # Build the vDSO image C files and link them in.
 vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
@@ -130,10 +134,6 @@ $(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE
 CPPFLAGS_vdso32/vdso32.lds = $(CPPFLAGS_vdso.lds)
 VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1
 
-targets += vdso32/vdso32.lds
-targets += vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
-targets += vdso32/vclock_gettime.o
-
 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO
 $(obj)/vdso32.so.dbg: KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
 $(obj)/vdso32.so.dbg: asflags-$(CONFIG_X86_64) += -m32
@@ -158,12 +158,7 @@ endif
 
 $(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
 
-$(obj)/vdso32.so.dbg: FORCE \
-		      $(obj)/vdso32/vdso32.lds \
-		      $(obj)/vdso32/vclock_gettime.o \
-		      $(obj)/vdso32/note.o \
-		      $(obj)/vdso32/system_call.o \
-		      $(obj)/vdso32/sigreturn.o
+$(obj)/vdso32.so.dbg: $(obj)/vdso32/vdso32.lds $(vobjs32) FORCE
 	$(call if_changed,vdso_and_check)
 
 #

Re: [PATCH 0/3] x86/vdso: Little clean-ups

[Andy Lutomirski]

On Mon, Apr 20, 2020 at 11:33 AM Dmitry Safonov <dima@arista.com> wrote:
>
> Resending some patches those weren't needed after timens series evolved,
> but still make sense. Nothing really important, just 3 nits here and
> there.

Acked-by: Andy Lutomirski <luto@kernel.org>