Merge remote-tracking branch 'remotes/vivier2/tags/linux-user-for-6.0-pull-request' into staging

linux-user pull request 20210313

- fix elfload
- fix executable page of /proc/self/maps
- add preserve-arg[0] support for binfmt_misc

# gpg: Signature made Sat 13 Mar 2021 09:47:23 GMT
# gpg:                using RSA key CD2F75DDC8E3A4DC2E4F5173F30C38BD3F2FBE3C
# gpg:                issuer "laurent@vivier.eu"
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>" [full]
# gpg:                 aka "Laurent Vivier <laurent@vivier.eu>" [full]
# gpg:                 aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>" [full]
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F  5173 F30C 38BD 3F2F BE3C

* remotes/vivier2/tags/linux-user-for-6.0-pull-request:
  linux-user/elfload: fix address calculation in fallback scenario
  linux-user/elfload: do not assume MAP_FIXED_NOREPLACE kernel support
  linux-user/elfload: munmap proper address in pgd_find_hole_fallback
  linux-user: manage binfmt-misc preserve-arg[0] flag
  linux-user: Fix executable page of /proc/self/maps

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 31 insertions, 7 deletions

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 140a971632..c6731013fd 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -2209,9 +2209,8 @@ static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk,
             void * mmap_start = mmap((void *) align_start, guest_size,
                                      PROT_NONE, flags, -1, 0);
             if (mmap_start != MAP_FAILED) {
-                munmap((void *) align_start, guest_size);
-                if (MAP_FIXED_NOREPLACE != 0 ||
-                    mmap_start == (void *) align_start) {
+                munmap(mmap_start, guest_size);
+                if (mmap_start == (void *) align_start) {
                     return (uintptr_t) mmap_start + offset;
                 }
             }
@@ -2236,7 +2235,8 @@ static uintptr_t pgb_find_hole(uintptr_t guest_loaddr, uintptr_t guest_size,
     brk = (uintptr_t)sbrk(0);
 
     if (!maps) {
-        return pgd_find_hole_fallback(guest_size, brk, align, offset);
+        ret = pgd_find_hole_fallback(guest_size, brk, align, offset);
+        return ret == -1 ? -1 : ret - guest_loaddr;
     }
 
     /* The first hole is before the first map entry. */
diff --git a/linux-user/main.c b/linux-user/main.c
index 4f4746dce8..f956afccab 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -26,6 +26,7 @@
 #include <sys/syscall.h>
 #include <sys/resource.h>
 #include <sys/shm.h>
+#include <linux/binfmts.h>
 
 #include "qapi/error.h"
 #include "qemu.h"
@@ -49,6 +50,11 @@
 #include "cpu_loop-common.h"
 #include "crypto/init.h"
 
+#ifndef AT_FLAGS_PRESERVE_ARGV0
+#define AT_FLAGS_PRESERVE_ARGV0_BIT 0
+#define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
+#endif
+
 char *exec_path;
 
 int singlestep;
@@ -632,6 +638,7 @@ int main(int argc, char **argv, char **envp)
     int execfd;
     int log_mask;
     unsigned long max_reserved_va;
+    bool preserve_argv0;
 
     error_init(argv[0]);
     module_call_init(MODULE_INIT_TRACE);
@@ -688,6 +695,9 @@ int main(int argc, char **argv, char **envp)
 
     init_qemu_uname_release();
 
+    /*
+     * Manage binfmt-misc open-binary flag
+     */
     execfd = qemu_getauxval(AT_EXECFD);
     if (execfd == 0) {
         execfd = open(exec_path, O_RDONLY);
@@ -697,6 +707,20 @@ int main(int argc, char **argv, char **envp)
         }
     }
 
+    /*
+     * get binfmt_misc flags
+     */
+    preserve_argv0 = !!(qemu_getauxval(AT_FLAGS) & AT_FLAGS_PRESERVE_ARGV0);
+
+    /*
+     * Manage binfmt-misc preserve-arg[0] flag
+     *    argv[optind]     full path to the binary
+     *    argv[optind + 1] original argv[0]
+     */
+    if (optind + 1 < argc && preserve_argv0) {
+        optind++;
+    }
+
     if (cpu_model == NULL) {
         cpu_model = cpu_get_model(get_elf_eflags(execfd));
     }
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 9522f603aa..1e508576c7 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -7890,9 +7890,9 @@ static int open_self_maps(void *cpu_env, int fd)
             count = dprintf(fd, TARGET_ABI_FMT_ptr "-" TARGET_ABI_FMT_ptr
                             " %c%c%c%c %08" PRIx64 " %s %"PRId64,
                             h2g(min), h2g(max - 1) + 1,
-                            e->is_read ? 'r' : '-',
-                            e->is_write ? 'w' : '-',
-                            e->is_exec ? 'x' : '-',
+                            (flags & PAGE_READ) ? 'r' : '-',
+                            (flags & PAGE_WRITE_ORG) ? 'w' : '-',
+                            (flags & PAGE_EXEC) ? 'x' : '-',
                             e->is_priv ? 'p' : '-',
                             (uint64_t) e->offset, e->dev, e->inode);
             if (path) {