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authorLinus Torvalds <torvalds@linux-foundation.org>2015-05-05 09:03:52 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-05-05 09:03:52 -0700
commitd9cee5d4f66ef36f69b0108dedbad7f7009bb6a8 (patch)
tree14dcf7cb49a884de4b5c55c5757f935c12462719
parentc02d7da3dd00cb32b58d9c87240456e19eebcc42 (diff)
parentf440c4ee3e53f767974fe60bcbc0b6687a5fb53f (diff)
downloadlinux-d9cee5d4f66ef36f69b0108dedbad7f7009bb6a8.tar.gz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fixes from Herbert Xu: "This fixes a build problem with bcm63xx and yet another fix to the memzero_explicit function to ensure that the memset is not elided" * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: hwrng: bcm63xx - Fix driver compilation lib: make memzero_explicit more robust against dead store elimination
-rw-r--r--drivers/char/hw_random/bcm63xx-rng.c18
-rw-r--r--include/linux/compiler-gcc.h16
-rw-r--r--include/linux/compiler-intel.h3
-rw-r--r--include/linux/compiler.h4
-rw-r--r--lib/string.c2
5 files changed, 32 insertions, 11 deletions
diff --git a/drivers/char/hw_random/bcm63xx-rng.c b/drivers/char/hw_random/bcm63xx-rng.c
index d1494ecd9e11..4b31f1387f37 100644
--- a/drivers/char/hw_random/bcm63xx-rng.c
+++ b/drivers/char/hw_random/bcm63xx-rng.c
@@ -57,7 +57,7 @@ static void bcm63xx_rng_cleanup(struct hwrng *rng)
val &= ~RNG_EN;
__raw_writel(val, priv->regs + RNG_CTRL);
- clk_didsable_unprepare(prov->clk);
+ clk_disable_unprepare(priv->clk);
}
static int bcm63xx_rng_data_present(struct hwrng *rng, int wait)
@@ -97,14 +97,14 @@ static int bcm63xx_rng_probe(struct platform_device *pdev)
priv->rng.name = pdev->name;
priv->rng.init = bcm63xx_rng_init;
priv->rng.cleanup = bcm63xx_rng_cleanup;
- prov->rng.data_present = bcm63xx_rng_data_present;
+ priv->rng.data_present = bcm63xx_rng_data_present;
priv->rng.data_read = bcm63xx_rng_data_read;
priv->clk = devm_clk_get(&pdev->dev, "ipsec");
if (IS_ERR(priv->clk)) {
- error = PTR_ERR(priv->clk);
- dev_err(&pdev->dev, "no clock for device: %d\n", error);
- return error;
+ ret = PTR_ERR(priv->clk);
+ dev_err(&pdev->dev, "no clock for device: %d\n", ret);
+ return ret;
}
if (!devm_request_mem_region(&pdev->dev, r->start,
@@ -120,11 +120,11 @@ static int bcm63xx_rng_probe(struct platform_device *pdev)
return -ENOMEM;
}
- error = devm_hwrng_register(&pdev->dev, &priv->rng);
- if (error) {
+ ret = devm_hwrng_register(&pdev->dev, &priv->rng);
+ if (ret) {
dev_err(&pdev->dev, "failed to register rng device: %d\n",
- error);
- return error;
+ ret);
+ return ret;
}
dev_info(&pdev->dev, "registered RNG driver\n");
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index cdf13ca7cac3..371e560d13cf 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -9,10 +9,24 @@
+ __GNUC_MINOR__ * 100 \
+ __GNUC_PATCHLEVEL__)
-
/* Optimization barrier */
+
/* The "volatile" is due to gcc bugs */
#define barrier() __asm__ __volatile__("": : :"memory")
+/*
+ * This version is i.e. to prevent dead stores elimination on @ptr
+ * where gcc and llvm may behave differently when otherwise using
+ * normal barrier(): while gcc behavior gets along with a normal
+ * barrier(), llvm needs an explicit input variable to be assumed
+ * clobbered. The issue is as follows: while the inline asm might
+ * access any memory it wants, the compiler could have fit all of
+ * @ptr into memory registers instead, and since @ptr never escaped
+ * from that, it proofed that the inline asm wasn't touching any of
+ * it. This version works well with both compilers, i.e. we're telling
+ * the compiler that the inline asm absolutely may see the contents
+ * of @ptr. See also: https://llvm.org/bugs/show_bug.cgi?id=15495
+ */
+#define barrier_data(ptr) __asm__ __volatile__("": :"r"(ptr) :"memory")
/*
* This macro obfuscates arithmetic on a variable address so that gcc
diff --git a/include/linux/compiler-intel.h b/include/linux/compiler-intel.h
index ba147a1727e6..0c9a2f2c2802 100644
--- a/include/linux/compiler-intel.h
+++ b/include/linux/compiler-intel.h
@@ -13,9 +13,12 @@
/* Intel ECC compiler doesn't support gcc specific asm stmts.
* It uses intrinsics to do the equivalent things.
*/
+#undef barrier_data
#undef RELOC_HIDE
#undef OPTIMIZER_HIDE_VAR
+#define barrier_data(ptr) barrier()
+
#define RELOC_HIDE(ptr, off) \
({ unsigned long __ptr; \
__ptr = (unsigned long) (ptr); \
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 0e41ca0e5927..867722591be2 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -169,6 +169,10 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
# define barrier() __memory_barrier()
#endif
+#ifndef barrier_data
+# define barrier_data(ptr) barrier()
+#endif
+
/* Unreachable code */
#ifndef unreachable
# define unreachable() do { } while (1)
diff --git a/lib/string.c b/lib/string.c
index a5792019193c..bb3d4b6993c4 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -607,7 +607,7 @@ EXPORT_SYMBOL(memset);
void memzero_explicit(void *s, size_t count)
{
memset(s, 0, count);
- barrier();
+ barrier_data(s);
}
EXPORT_SYMBOL(memzero_explicit);