Merge tag 'for-linus-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Richard Weinberger:

 - KASAN support for x86_64

 - noreboot command line option, just like qemu's -no-reboot

 - Various fixes and cleanups

* tag 'for-linus-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: include sys/types.h for size_t
  um: Replace to_phys() and to_virt() with less generic function names
  um: Add missing apply_returns()
  um: add "noreboot" command line option for PANIC_TIMEOUT=-1 setups
  um: include linux/stddef.h for __always_inline
  UML: add support for KASAN under x86_64
  mm: Add PAGE_ALIGN_DOWN macro
  um: random: Don't initialise hwrng struct with zero
  um: remove unused mm_copy_segments
  um: remove unused variable
  um: Remove straying parenthesis
  um: x86: print RIP with symbol
  arch: um: Fix build for statically linked UML w/ constructors
  x86/um: Kconfig: Fix indentation
  um/drivers: Kconfig: Fix indentation
  um: Kconfig: Fix indentation

4 files changed, 41 insertions, 5 deletions

diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c
index 3c1b77474d2d..8530b2e08604 100644
--- a/arch/um/os-Linux/mem.c
+++ b/arch/um/os-Linux/mem.c
@@ -17,6 +17,28 @@
 #include <init.h>
 #include <os.h>
 
+/*
+ * kasan_map_memory - maps memory from @start with a size of @len.
+ * The allocated memory is filled with zeroes upon success.
+ * @start: the start address of the memory to be mapped
+ * @len: the length of the memory to be mapped
+ *
+ * This function is used to map shadow memory for KASAN in uml
+ */
+void kasan_map_memory(void *start, size_t len)
+{
+	if (mmap(start,
+		 len,
+		 PROT_READ|PROT_WRITE,
+		 MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE|MAP_NORESERVE,
+		 -1,
+		 0) == MAP_FAILED) {
+		os_info("Couldn't allocate shadow memory: %s\n.",
+			strerror(errno));
+		exit(1);
+	}
+}
+
 /* Set by make_tempfile() during early boot. */
 static char *tempdir = NULL;
 
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index c316c993a949..b24db6017ded 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -5,6 +5,7 @@
  */
 
 #include <stdlib.h>
+#include <stdbool.h>
 #include <unistd.h>
 #include <sched.h>
 #include <errno.h>
@@ -707,10 +708,24 @@ void halt_skas(void)
 	UML_LONGJMP(&initial_jmpbuf, INIT_JMP_HALT);
 }
 
+static bool noreboot;
+
+static int __init noreboot_cmd_param(char *str, int *add)
+{
+	noreboot = true;
+	return 0;
+}
+
+__uml_setup("noreboot", noreboot_cmd_param,
+"noreboot\n"
+"    Rather than rebooting, exit always, akin to QEMU's -no-reboot option.\n"
+"    This is useful if you're using CONFIG_PANIC_TIMEOUT in order to catch\n"
+"    crashes in CI\n");
+
 void reboot_skas(void)
 {
 	block_signals_trace();
-	UML_LONGJMP(&initial_jmpbuf, INIT_JMP_REBOOT);
+	UML_LONGJMP(&initial_jmpbuf, noreboot ? INIT_JMP_HALT : INIT_JMP_REBOOT);
 }
 
 void __switch_mm(struct mm_id *mm_idp)
diff --git a/arch/um/os-Linux/umid.c b/arch/um/os-Linux/umid.c
index a3dd61521d24..7a1abb829930 100644
--- a/arch/um/os-Linux/umid.c
+++ b/arch/um/os-Linux/umid.c
@@ -136,7 +136,7 @@ out:
 static inline int is_umdir_used(char *dir)
 {
 	char pid[sizeof("nnnnnnnnn")], *end, *file;
-	int dead, fd, p, n, err;
+	int fd, p, n, err;
 	size_t filelen = strlen(dir) + sizeof("/pid") + 1;
 
 	file = malloc(filelen);
@@ -145,7 +145,6 @@ static inline int is_umdir_used(char *dir)
 
 	snprintf(file, filelen, "%s/pid", dir);
 
-	dead = 0;
 	fd = open(file, O_RDONLY);
 	if (fd < 0) {
 		fd = -errno;
diff --git a/arch/um/os-Linux/user_syms.c b/arch/um/os-Linux/user_syms.c
index 715594fe5719..cb667c9225ab 100644
--- a/arch/um/os-Linux/user_syms.c
+++ b/arch/um/os-Linux/user_syms.c
@@ -27,10 +27,10 @@ EXPORT_SYMBOL(strstr);
 #ifndef __x86_64__
 extern void *memcpy(void *, const void *, size_t);
 EXPORT_SYMBOL(memcpy);
-#endif
-
 EXPORT_SYMBOL(memmove);
 EXPORT_SYMBOL(memset);
+#endif
+
 EXPORT_SYMBOL(printf);
 
 /* Here, instead, I can provide a fake prototype. Yes, someone cares: genksyms.