Merge tag 'v4.19.249' of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux into 12.1-alioth

This is the 4.19.249 stable release

Author: raystef66

Documentation/admin-guide/kernel-parameters.txt

@@ -3732,6 +3732,12 @@
 			fully seed the kernel's CRNG. Default is controlled
 			by CONFIG_RANDOM_TRUST_CPU.
 
+	random.trust_bootloader={on,off}
+			[KNL] Enable or disable trusting the use of a
+			seed passed by the bootloader (if available) to
+			fully seed the kernel's CRNG. Default is controlled
+			by CONFIG_RANDOM_TRUST_BOOTLOADER.
+
 	ras=option[,option,...]	[KNL] RAS-specific options
 
 		cec_disable	[X86]

Documentation/sysctl/kernel.txt

@@ -850,9 +850,40 @@ The kernel command line parameter printk.devkmsg= overrides this and is
 a one-time setting until next reboot: once set, it cannot be changed by
 this sysctl interface anymore.
 
-==============================================================
+pty
+===
+
+See Documentation/filesystems/devpts.rst.
+
+
+random
+======
+
+This is a directory, with the following entries:
+
+* ``boot_id``: a UUID generated the first time this is retrieved, and
+  unvarying after that;
+
+* ``uuid``: a UUID generated every time this is retrieved (this can
+  thus be used to generate UUIDs at will);
+
+* ``entropy_avail``: the pool's entropy count, in bits;
+
+* ``poolsize``: the entropy pool size, in bits;
+
+* ``urandom_min_reseed_secs``: obsolete (used to determine the minimum
+  number of seconds between urandom pool reseeding). This file is
+  writable for compatibility purposes, but writing to it has no effect
+  on any RNG behavior;
+
+* ``write_wakeup_threshold``: when the entropy count drops below this
+  (as a number of bits), processes waiting to write to ``/dev/random``
+  are woken up. This file is writable for compatibility purposes, but
+  writing to it has no effect on any RNG behavior.
+
 
-randomize_va_space:
+randomize_va_space
+==================
 
 This option can be used to select the type of process address
 space randomization that is used in the system, for architectures

MAINTAINERS

@@ -12280,6 +12280,7 @@ F:	arch/mips/configs/generic/board-ranchu.config
 
 RANDOM NUMBER DRIVER
 M:	"Theodore Ts'o" <[email protected]>
+M:	Jason A. Donenfeld <[email protected]>
 S:	Maintained
 F:	drivers/char/random.c
 

Makefile

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 VERSION = 4
 PATCHLEVEL = 19
-SUBLEVEL = 248
+SUBLEVEL = 249
 EXTRAVERSION =
 NAME = "People's Front"
 

arch/alpha/include/asm/timex.h

@@ -28,5 +28,6 @@ static inline cycles_t get_cycles (void)
 	__asm__ __volatile__ ("rpcc %0" : "=r"(ret));
 	return ret;
 }
+#define get_cycles get_cycles
 
 #endif

arch/arm/include/asm/timex.h

@@ -14,5 +14,6 @@
 
 typedef unsigned long cycles_t;
 #define get_cycles()	({ cycles_t c; read_current_timer(&c) ? 0 : c; })
+#define random_get_entropy() (((unsigned long)get_cycles()) ?: random_get_entropy_fallback())
 
 #endif

arch/arm64/kernel/ftrace.c

@@ -72,7 +72,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 {
 	unsigned long pc = rec->ip;
 	u32 old, new;
-	long offset = (long)pc - (long)addr;
+	long offset = (long)addr - (long)pc;
 
 	if (offset < -SZ_128M || offset >= SZ_128M) {
 #ifdef CONFIG_ARM64_MODULE_PLTS
@@ -151,7 +151,7 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
 	unsigned long pc = rec->ip;
 	bool validate = true;
 	u32 old = 0, new;
-	long offset = (long)pc - (long)addr;
+	long offset = (long)addr - (long)pc;
 
 	if (offset < -SZ_128M || offset >= SZ_128M) {
 #ifdef CONFIG_ARM64_MODULE_PLTS

arch/ia64/include/asm/timex.h

@@ -39,6 +39,7 @@ get_cycles (void)
 	ret = ia64_getreg(_IA64_REG_AR_ITC);
 	return ret;
 }
+#define get_cycles get_cycles
 
 extern void ia64_cpu_local_tick (void);
 extern unsigned long long ia64_native_sched_clock (void);

arch/m68k/include/asm/timex.h

@@ -35,7 +35,7 @@ static inline unsigned long random_get_entropy(void)
 {
 	if (mach_random_get_entropy)
 		return mach_random_get_entropy();
-	return 0;
+	return random_get_entropy_fallback();
 }
 #define random_get_entropy	random_get_entropy
 

arch/mips/include/asm/timex.h

@@ -76,25 +76,24 @@ static inline cycles_t get_cycles(void)
 	else
 		return 0;	/* no usable counter */
 }
+#define get_cycles get_cycles
 
 /*
  * Like get_cycles - but where c0_count is not available we desperately
  * use c0_random in an attempt to get at least a little bit of entropy.
- *
- * R6000 and R6000A neither have a count register nor a random register.
- * That leaves no entropy source in the CPU itself.
  */
 static inline unsigned long random_get_entropy(void)
 {
-	unsigned int prid = read_c0_prid();
-	unsigned int imp = prid & PRID_IMP_MASK;
+	unsigned int c0_random;
 
-	if (can_use_mips_counter(prid))
+	if (can_use_mips_counter(read_c0_prid()))
 		return read_c0_count();
-	else if (likely(imp != PRID_IMP_R6000 && imp != PRID_IMP_R6000A))
-		return read_c0_random();
+
+	if (cpu_has_3kex)
+		c0_random = (read_c0_random() >> 8) & 0x3f;
 	else
-		return 0;	/* no usable register */
+		c0_random = read_c0_random() & 0x3f;
+	return (random_get_entropy_fallback() << 6) | (0x3f - c0_random);
 }
 #define random_get_entropy random_get_entropy