diff mbox series

um: restore process name

Message ID 20241010161411.c576e2aeb3e5.I244d4f34b8a8555ee5bec0e1cf5027bce4cc491b@changeid
State New
Headers show
Series um: restore process name | expand

Commit Message

Johannes Berg Oct. 10, 2024, 2:14 p.m. UTC 
From: Johannes Berg <johannes.berg@intel.com>

After the execve() to disable ASLR, comm is now "exe",
which is a bit confusing. Use readlink() to get this
to the right name again.

Disable stack frame size warnings on main.o since it's
part of the initial userspace and can use larger stack.

Fixes: 68b9883cc16e ("um: Discover host_task_size from envp")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 arch/um/os-Linux/Makefile |  2 ++
 arch/um/os-Linux/main.c   | 14 ++++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/arch/um/os-Linux/Makefile b/arch/um/os-Linux/Makefile
index 544e0b344c75..049dfa5bc9c6 100644
--- a/arch/um/os-Linux/Makefile
+++ b/arch/um/os-Linux/Makefile
@@ -12,6 +12,8 @@  obj-y = execvp.o file.o helper.o irq.o main.o mem.o process.o \
 
 CFLAGS_signal.o += -Wframe-larger-than=4096
 
+CFLAGS_main.o += -Wno-frame-larger-than
+
 obj-$(CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA) += elf_aux.o
 
 USER_OBJS := $(user-objs-y) elf_aux.o execvp.o file.o helper.o irq.o \
diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c
index 8a52c49c5361..31dba0912a19 100644
--- a/arch/um/os-Linux/main.c
+++ b/arch/um/os-Linux/main.c
@@ -10,6 +10,7 @@ 
 #include <errno.h>
 #include <signal.h>
 #include <string.h>
+#include <limits.h>
 #include <sys/resource.h>
 #include <sys/personality.h>
 #include <as-layout.h>
@@ -112,8 +113,17 @@  int __init main(int argc, char **argv, char **envp)
 	/* Disable randomization and re-exec if it was changed successfully */
 	ret = personality(PER_LINUX | ADDR_NO_RANDOMIZE);
 	if (ret >= 0 && (ret & (PER_LINUX | ADDR_NO_RANDOMIZE)) !=
-			 (PER_LINUX | ADDR_NO_RANDOMIZE))
-		execve("/proc/self/exe", argv, envp);
+			 (PER_LINUX | ADDR_NO_RANDOMIZE)) {
+		char buf[PATH_MAX];
+		ssize_t ret;
+
+		ret = readlink("/proc/self/exe", buf, sizeof(buf));
+		if (ret < 0 || ret >= sizeof(buf)) {
+			perror("readlink failure");
+			exit(1);
+		}
+		execve(buf, argv, envp);
+	}
 
 	set_stklim();