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From: Ilya Leoshkevich <iii@linux.ibm.com>
To: "Alex Bennée" <alex.bennee@linaro.org>,
	"Laurent Vivier" <laurent@vivier.eu>,
	"Peter Maydell" <peter.maydell@linaro.org>,
	"Richard Henderson" <richard.henderson@linaro.org>,
	"David Hildenbrand" <david@redhat.com>
Cc: "Philippe Mathieu-Daudé" <philmd@linaro.org>,
	qemu-devel@nongnu.org, qemu-arm@nongnu.org,
	qemu-s390x@nongnu.org, "Ilya Leoshkevich" <iii@linux.ibm.com>
Subject: [PATCH v3 2/8] linux-user: Add "safe" parameter to do_guest_openat()
Date: Tue,  6 Jun 2023 15:27:37 +0200	[thread overview]
Message-ID: <20230606132743.1386003-3-iii@linux.ibm.com> (raw)
In-Reply-To: <20230606132743.1386003-1-iii@linux.ibm.com>

gdbstub cannot meaningfully handle QEMU_ERESTARTSYS, and it doesn't
need to. Add a parameter to do_guest_openat() that makes it use
openat() instead of safe_openat(), so that it becomes usable from
gdbstub.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 linux-user/qemu.h    |  2 +-
 linux-user/syscall.c | 18 +++++++++++++-----
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index a5830ec2396..9b8e0860d70 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -166,7 +166,7 @@ typedef struct TaskState {
 
 abi_long do_brk(abi_ulong new_brk);
 int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname,
-                    int flags, mode_t mode);
+                    int flags, mode_t mode, bool safe);
 ssize_t do_guest_readlink(const char *pathname, char *buf, size_t bufsiz);
 
 /* user access */
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 2d3070cfd62..28a0b1f7882 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -8449,7 +8449,7 @@ static int open_hardware(CPUArchState *cpu_env, int fd)
 #endif
 
 int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname,
-                    int flags, mode_t mode)
+                    int flags, mode_t mode, bool safe)
 {
     struct fake_open {
         const char *filename;
@@ -8476,7 +8476,11 @@ int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname,
     };
 
     if (is_proc_myself(pathname, "exe")) {
-        return safe_openat(dirfd, exec_path, flags, mode);
+        if (safe) {
+            return safe_openat(dirfd, exec_path, flags, mode);
+        } else {
+            return openat(dirfd, exec_path, flags, mode);
+        }
     }
 
     for (fake_open = fakes; fake_open->filename; fake_open++) {
@@ -8518,7 +8522,11 @@ int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname,
         return fd;
     }
 
-    return safe_openat(dirfd, path(pathname), flags, mode);
+    if (safe) {
+        return safe_openat(dirfd, path(pathname), flags, mode);
+    } else {
+        return openat(dirfd, path(pathname), flags, mode);
+    }
 }
 
 ssize_t do_guest_readlink(const char *pathname, char *buf, size_t bufsiz)
@@ -9027,7 +9035,7 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
             return -TARGET_EFAULT;
         ret = get_errno(do_guest_openat(cpu_env, AT_FDCWD, p,
                                   target_to_host_bitmask(arg2, fcntl_flags_tbl),
-                                  arg3));
+                                  arg3, true));
         fd_trans_unregister(ret);
         unlock_user(p, arg1, 0);
         return ret;
@@ -9037,7 +9045,7 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
             return -TARGET_EFAULT;
         ret = get_errno(do_guest_openat(cpu_env, arg1, p,
                                   target_to_host_bitmask(arg3, fcntl_flags_tbl),
-                                  arg4));
+                                  arg4, true));
         fd_trans_unregister(ret);
         unlock_user(p, arg2, 0);
         return ret;
-- 
2.40.1



  parent reply	other threads:[~2023-06-06 13:30 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-06 13:27 [PATCH v3 0/8] gdbstub: Add support for info proc mappings Ilya Leoshkevich
2023-06-06 13:27 ` [PATCH v3 1/8] linux-user: Expose do_guest_openat() and do_guest_readlink() Ilya Leoshkevich
2023-06-06 16:33   ` Richard Henderson
2023-06-06 13:27 ` Ilya Leoshkevich [this message]
2023-06-06 18:24   ` [PATCH v3 2/8] linux-user: Add "safe" parameter to do_guest_openat() Richard Henderson
2023-06-06 19:29     ` Ilya Leoshkevich
2023-06-06 20:35       ` Richard Henderson
2023-06-06 13:27 ` [PATCH v3 3/8] linux-user: Emulate /proc/self/smaps Ilya Leoshkevich
2023-06-06 18:00   ` Richard Henderson
2023-06-06 13:27 ` [PATCH v3 4/8] gdbstub: Expose gdb_get_process() and gdb_get_first_cpu_in_process() Ilya Leoshkevich
2023-06-06 13:27 ` [PATCH v3 5/8] gdbstub: Report the actual qemu-user pid Ilya Leoshkevich
2023-06-06 13:27 ` [PATCH v3 6/8] gdbstub: Add support for info proc mappings Ilya Leoshkevich
2023-06-21 10:19   ` Alex Bennée
2023-06-06 13:27 ` [PATCH v3 7/8] docs: Document security implications of debugging Ilya Leoshkevich
2023-06-06 13:27 ` [PATCH v3 8/8] tests/tcg: Add a test for info proc mappings Ilya Leoshkevich
2023-06-21 10:21   ` Alex Bennée
2023-06-21 13:48     ` Ilya Leoshkevich
2023-06-21 14:43       ` Alex Bennée

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