linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] Remove structure passing and assignment to save stack and no coping structures.
@ 2018-01-13 18:48 Karim Eshapa
  0 siblings, 0 replies; 3+ messages in thread
From: Karim Eshapa @ 2018-01-13 18:48 UTC (permalink / raw)
  To: ast; +Cc: daniel, davem, ecree, netdev, linux-kernel, Karim Eshapa

Signed-off-by: Karim Eshapa <karim.eshapa@gmail.com>

Thanks,
Karim
---
 include/linux/tnum.h  |  2 +-
 kernel/bpf/tnum.c     | 13 +++++++------
 kernel/bpf/verifier.c | 12 ++++++++----
 3 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/include/linux/tnum.h b/include/linux/tnum.h
index 0d2d3da..ddb1250 100644
--- a/include/linux/tnum.h
+++ b/include/linux/tnum.h
@@ -26,7 +26,7 @@ struct tnum tnum_lshift(struct tnum a, u8 shift);
 /* Shift a tnum right (by a fixed shift) */
 struct tnum tnum_rshift(struct tnum a, u8 shift);
 /* Add two tnums, return @a + @b */
-struct tnum tnum_add(struct tnum a, struct tnum b);
+void tnum_add(struct tnum *res, struct tnum *a, struct tnum *b);
 /* Subtract two tnums, return @a - @b */
 struct tnum tnum_sub(struct tnum a, struct tnum b);
 /* Bitwise-AND, return @a & @b */
diff --git a/kernel/bpf/tnum.c b/kernel/bpf/tnum.c
index 1f4bf68..f7f8b10 100644
--- a/kernel/bpf/tnum.c
+++ b/kernel/bpf/tnum.c
@@ -43,16 +43,17 @@ struct tnum tnum_rshift(struct tnum a, u8 shift)
 	return TNUM(a.value >> shift, a.mask >> shift);
 }
 
-struct tnum tnum_add(struct tnum a, struct tnum b)
+void tnum tnum_add(struct tnum *res, struct tnum *a, struct tnum *b)
 {
 	u64 sm, sv, sigma, chi, mu;
 
-	sm = a.mask + b.mask;
-	sv = a.value + b.value;
+	sm = a->mask + b->mask;
+	sv = a->value + b->value;
 	sigma = sm + sv;
 	chi = sigma ^ sv;
-	mu = chi | a.mask | b.mask;
-	return TNUM(sv & ~mu, mu);
+	mu = chi | a->mask | b->mask;
+	res->value = (sv & ~mu);
+	res->mask = mu;
 }
 
 struct tnum tnum_sub(struct tnum a, struct tnum b)
@@ -102,7 +103,7 @@ static struct tnum hma(struct tnum acc, u64 value, u64 mask)
 {
 	while (mask) {
 		if (mask & 1)
-			acc = tnum_add(acc, TNUM(0, value));
+			tnum_add(&acc, &acc, &TNUM(0, value));
 		mask >>= 1;
 		value <<= 1;
 	}
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index b414d6b..4acc16c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -999,7 +999,8 @@ static int check_pkt_ptr_alignment(struct bpf_verifier_env *env,
 	 */
 	ip_align = 2;
 
-	reg_off = tnum_add(reg->var_off, tnum_const(ip_align + reg->off + off));
+	tnum_add(&reg_off, &reg->var_off,
+		&tnum_const(ip_align + reg->off + off));
 	if (!tnum_is_aligned(reg_off, size)) {
 		char tn_buf[48];
 
@@ -1024,7 +1025,8 @@ static int check_generic_ptr_alignment(struct bpf_verifier_env *env,
 	if (!strict || size == 1)
 		return 0;
 
-	reg_off = tnum_add(reg->var_off, tnum_const(reg->off + off));
+	tnum_add(&reg_off, &reg->var_off,
+		&tnum_const(reg->off + off));
 	if (!tnum_is_aligned(reg_off, size)) {
 		char tn_buf[48];
 
@@ -1971,7 +1973,8 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 			dst_reg->umin_value = umin_ptr + umin_val;
 			dst_reg->umax_value = umax_ptr + umax_val;
 		}
-		dst_reg->var_off = tnum_add(ptr_reg->var_off, off_reg->var_off);
+		tnum_add(&dst_reg->var_off, &ptr_reg->var_off,
+			&off_reg->var_off);
 		dst_reg->off = ptr_reg->off;
 		if (reg_is_pkt_pointer(ptr_reg)) {
 			dst_reg->id = ++env->id_gen;
@@ -2108,7 +2111,8 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 			dst_reg->umin_value += umin_val;
 			dst_reg->umax_value += umax_val;
 		}
-		dst_reg->var_off = tnum_add(dst_reg->var_off, src_reg.var_off);
+		tnum_add(&dst_reg->var_off, &dst_reg->var_off,
+			&src_reg.var_off);
 		break;
 	case BPF_SUB:
 		if (signed_sub_overflows(dst_reg->smin_value, smax_val) ||
-- 
2.7.4

^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [PATCH] Remove structure passing and assignment to save stack and no coping structures.
  2018-01-13 19:26 Karim Eshapa
@ 2018-01-16  6:57 ` kbuild test robot
  0 siblings, 0 replies; 3+ messages in thread
From: kbuild test robot @ 2018-01-16  6:57 UTC (permalink / raw)
  To: Karim Eshapa
  Cc: kbuild-all, ast, daniel, davem, ecree, netdev, linux-kernel,
	Karim Eshapa

Hi Karim,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v4.15-rc8 next-20180115]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Karim-Eshapa/Remove-structure-passing-and-assignment-to-save-stack-and-no-coping-structures/20180116-130502
reproduce:
        # apt-get install sparse
        make ARCH=x86_64 allmodconfig
        make C=1 CF=-D__CHECK_ENDIAN__


sparse warnings: (new ones prefixed by >>)

>> kernel/bpf/verifier.c:1002:29: sparse: incorrect type in argument 2 (different modifiers) @@ expected struct tnum @@ got structstruct tnum @@
   kernel/bpf/verifier.c:1002:29: expected struct tnum
   kernel/bpf/verifier.c:1002:29: got struct tnum const
>> kernel/bpf/verifier.c:1003:17: sparse: not addressable
   kernel/bpf/verifier.c:1028:29: sparse: incorrect type in argument 2 (different modifiers) @@ expected struct tnum @@ got structstruct tnum @@
   kernel/bpf/verifier.c:1028:29: expected struct tnum
   kernel/bpf/verifier.c:1028:29: got struct tnum const
   kernel/bpf/verifier.c:1029:17: sparse: not addressable
   kernel/bpf/verifier.c:1969:46: sparse: incorrect type in argument 2 (different modifiers) @@ expected struct tnum @@ got structstruct tnum @@
   kernel/bpf/verifier.c:1969:46: expected struct tnum
   kernel/bpf/verifier.c:1969:46: got struct tnum const
>> kernel/bpf/verifier.c:1970:26: sparse: incorrect type in argument 3 (different modifiers) @@ expected struct tnum lib @@ got structstruct tnum lib @@
   kernel/bpf/verifier.c:1970:26: expected struct tnum lib
   kernel/bpf/verifier.c:1970:26: got struct tnum const
   kernel/bpf/verifier.c:4527:38: sparse: subtraction of Share your drugs
>> kernel/bpf/verifier.c:1002:17: sparse: call with no type!
   kernel/bpf/verifier.c:1028:17: sparse: call with no type!
   kernel/bpf/verifier.c: In function 'check_pkt_ptr_alignment':
   kernel/bpf/verifier.c:1003:3: error: lvalue required as unary '&' operand
    &tnum_const(ip_align + reg->off + off));
    ^
   kernel/bpf/verifier.c:1002:21: warning: passing argument 2 of 'tnum_add' discards 'const' qualifier from pointer target type
    tnum_add(&reg_off, &reg->var_off,
    ^
   In file included from include/linux/bpf_verifier.h:12:0,
    from kernel/bpf/verifier.c:17:
   include/linux/tnum.h:29:6: note: expected 'struct tnum but argument is of type 'const struct tnum
    void tnum_add(struct tnum struct tnum struct tnum
    ^~~~~~~~
   kernel/bpf/verifier.c: In function 'check_generic_ptr_alignment':
   kernel/bpf/verifier.c:1029:3: error: lvalue required as unary '&' operand
    &tnum_const(reg->off + off));
    ^
   kernel/bpf/verifier.c:1028:21: warning: passing argument 2 of 'tnum_add' discards 'const' qualifier from pointer target type
    tnum_add(&reg_off, &reg->var_off,
    ^
   In file included from include/linux/bpf_verifier.h:12:0,
    from kernel/bpf/verifier.c:17:
   include/linux/tnum.h:29:6: note: expected 'struct tnum but argument is of type 'const struct tnum
    void tnum_add(struct tnum struct tnum struct tnum
    ^~~~~~~~
   kernel/bpf/verifier.c: In function 'adjust_ptr_min_max_vals':
   kernel/bpf/verifier.c:1969:31: warning: passing argument 2 of 'tnum_add' discards 'const' qualifier from pointer target type
    tnum_add(&dst_reg->var_off, &ptr_reg->var_off,
    ^
   In file included from include/linux/bpf_verifier.h:12:0,
    from kernel/bpf/verifier.c:17:
   include/linux/tnum.h:29:6: note: expected 'struct tnum but argument is of type 'const struct tnum
    void tnum_add(struct tnum struct tnum struct tnum
    ^~~~~~~~
   kernel/bpf/verifier.c:1970:4: warning: passing argument 3 of 'tnum_add' discards 'const' qualifier from pointer target type
    &off_reg->var_off);
    ^
   In file included from include/linux/bpf_verifier.h:12:0,
    from kernel/bpf/verifier.c:17:
   include/linux/tnum.h:29:6: note: expected 'struct tnum but argument is of type 'const struct tnum
    void tnum_add(struct tnum struct tnum struct tnum
    ^~~~~~~~

vim +1002 kernel/bpf/verifier.c

   980	
   981	static int check_pkt_ptr_alignment(struct bpf_verifier_env *env,
   982					   const struct bpf_reg_state *reg,
   983					   int off, int size, bool strict)
   984	{
   985		struct tnum reg_off;
   986		int ip_align;
   987	
   988		/* Byte size accesses are always allowed. */
   989		if (!strict || size == 1)
   990			return 0;
   991	
   992		/* For platforms that do not have a Kconfig enabling
   993		 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS the value of
   994		 * NET_IP_ALIGN is universally set to '2'.  And on platforms
   995		 * that do set CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS, we get
   996		 * to this code only in strict mode where we want to emulate
   997		 * the NET_IP_ALIGN==2 checking.  Therefore use an
   998		 * unconditional IP align value of '2'.
   999		 */
  1000		ip_align = 2;
  1001	
> 1002		tnum_add(&reg_off, &reg->var_off,
> 1003			&tnum_const(ip_align + reg->off + off));
  1004		if (!tnum_is_aligned(reg_off, size)) {
  1005			char tn_buf[48];
  1006	
  1007			tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
  1008			verbose(env,
  1009				"misaligned packet access off %d+%s+%d+%d size %d\n",
  1010				ip_align, tn_buf, reg->off, off, size);
  1011			return -EACCES;
  1012		}
  1013	
  1014		return 0;
  1015	}
  1016	
  1017	static int check_generic_ptr_alignment(struct bpf_verifier_env *env,
  1018					       const struct bpf_reg_state *reg,
  1019					       const char *pointer_desc,
  1020					       int off, int size, bool strict)
  1021	{
  1022		struct tnum reg_off;
  1023	
  1024		/* Byte size accesses are always allowed. */
  1025		if (!strict || size == 1)
  1026			return 0;
  1027	
> 1028		tnum_add(&reg_off, &reg->var_off,
  1029			&tnum_const(reg->off + off));
  1030		if (!tnum_is_aligned(reg_off, size)) {
  1031			char tn_buf[48];
  1032	
  1033			tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
  1034			verbose(env, "misaligned %saccess off %s+%d+%d size %d\n",
  1035				pointer_desc, tn_buf, reg->off, off, size);
  1036			return -EACCES;
  1037		}
  1038	
  1039		return 0;
  1040	}
  1041	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

^ permalink raw reply	[flat|nested] 3+ messages in thread
* [PATCH] Remove structure passing and assignment to save stack and no coping structures.
@ 2018-01-13 19:26 Karim Eshapa
  2018-01-16  6:57 ` kbuild test robot
  0 siblings, 1 reply; 3+ messages in thread
From: Karim Eshapa @ 2018-01-13 19:26 UTC (permalink / raw)
  To: ast; +Cc: daniel, davem, ecree, netdev, linux-kernel, Karim Eshapa

Signed-off-by: Karim Eshapa <karim.eshapa@gmail.com>

Thanks,
Karim
---
 include/linux/tnum.h  |  2 +-
 kernel/bpf/tnum.c     | 13 +++++++------
 kernel/bpf/verifier.c | 12 ++++++++----
 3 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/include/linux/tnum.h b/include/linux/tnum.h
index 0d2d3da..ddb1250 100644
--- a/include/linux/tnum.h
+++ b/include/linux/tnum.h
@@ -26,7 +26,7 @@ struct tnum tnum_lshift(struct tnum a, u8 shift);
 /* Shift a tnum right (by a fixed shift) */
 struct tnum tnum_rshift(struct tnum a, u8 shift);
 /* Add two tnums, return @a + @b */
-struct tnum tnum_add(struct tnum a, struct tnum b);
+void tnum_add(struct tnum *res, struct tnum *a, struct tnum *b);
 /* Subtract two tnums, return @a - @b */
 struct tnum tnum_sub(struct tnum a, struct tnum b);
 /* Bitwise-AND, return @a & @b */
diff --git a/kernel/bpf/tnum.c b/kernel/bpf/tnum.c
index 1f4bf68..f7f8b10 100644
--- a/kernel/bpf/tnum.c
+++ b/kernel/bpf/tnum.c
@@ -43,16 +43,17 @@ struct tnum tnum_rshift(struct tnum a, u8 shift)
 	return TNUM(a.value >> shift, a.mask >> shift);
 }
 
-struct tnum tnum_add(struct tnum a, struct tnum b)
+void tnum_add(struct tnum *res, struct tnum *a, struct tnum *b)
 {
 	u64 sm, sv, sigma, chi, mu;
 
-	sm = a.mask + b.mask;
-	sv = a.value + b.value;
+	sm = a->mask + b->mask;
+	sv = a->value + b->value;
 	sigma = sm + sv;
 	chi = sigma ^ sv;
-	mu = chi | a.mask | b.mask;
-	return TNUM(sv & ~mu, mu);
+	mu = chi | a->mask | b->mask;
+	res->value = (sv & ~mu);
+	res->mask = mu;
 }
 
 struct tnum tnum_sub(struct tnum a, struct tnum b)
@@ -102,7 +103,7 @@ static struct tnum hma(struct tnum acc, u64 value, u64 mask)
 {
 	while (mask) {
 		if (mask & 1)
-			acc = tnum_add(acc, TNUM(0, value));
+			tnum_add(&acc, &acc, &TNUM(0, value));
 		mask >>= 1;
 		value <<= 1;
 	}
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index b414d6b..4acc16c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -999,7 +999,8 @@ static int check_pkt_ptr_alignment(struct bpf_verifier_env *env,
 	 */
 	ip_align = 2;
 
-	reg_off = tnum_add(reg->var_off, tnum_const(ip_align + reg->off + off));
+	tnum_add(&reg_off, &reg->var_off,
+		&tnum_const(ip_align + reg->off + off));
 	if (!tnum_is_aligned(reg_off, size)) {
 		char tn_buf[48];
 
@@ -1024,7 +1025,8 @@ static int check_generic_ptr_alignment(struct bpf_verifier_env *env,
 	if (!strict || size == 1)
 		return 0;
 
-	reg_off = tnum_add(reg->var_off, tnum_const(reg->off + off));
+	tnum_add(&reg_off, &reg->var_off,
+		&tnum_const(reg->off + off));
 	if (!tnum_is_aligned(reg_off, size)) {
 		char tn_buf[48];
 
@@ -1971,7 +1973,8 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 			dst_reg->umin_value = umin_ptr + umin_val;
 			dst_reg->umax_value = umax_ptr + umax_val;
 		}
-		dst_reg->var_off = tnum_add(ptr_reg->var_off, off_reg->var_off);
+		tnum_add(&dst_reg->var_off, &ptr_reg->var_off,
+			&off_reg->var_off);
 		dst_reg->off = ptr_reg->off;
 		if (reg_is_pkt_pointer(ptr_reg)) {
 			dst_reg->id = ++env->id_gen;
@@ -2108,7 +2111,8 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
 			dst_reg->umin_value += umin_val;
 			dst_reg->umax_value += umax_val;
 		}
-		dst_reg->var_off = tnum_add(dst_reg->var_off, src_reg.var_off);
+		tnum_add(&dst_reg->var_off, &dst_reg->var_off,
+			&src_reg.var_off);
 		break;
 	case BPF_SUB:
 		if (signed_sub_overflows(dst_reg->smin_value, smax_val) ||
-- 
2.7.4

^ permalink raw reply related	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-01-16  6:58 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-01-13 18:48 [PATCH] Remove structure passing and assignment to save stack and no coping structures Karim Eshapa
2018-01-13 19:26 Karim Eshapa
2018-01-16  6:57 ` kbuild test robot

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).