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Re: [PATCH v2 02/11] linux-user: Fix the execfd case of /proc/self/exe o
From: |
Laurent Vivier |
Subject: |
Re: [PATCH v2 02/11] linux-user: Fix the execfd case of /proc/self/exe open |
Date: |
Sun, 20 Jun 2021 16:16:06 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 |
Le 31/05/2021 à 07:50, YAMAMOTO Takashi a écrit :
> It's problematic to return AT_EXECFD as it is because the user app
> would close it.
> This patch opens it via /proc/self/fd instead.
>
> Signed-off-by: YAMAMOTO Takashi <yamamoto@midokura.com>
> ---
> linux-user/syscall.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index a2b03ecb8b..14a63518e2 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -8118,7 +8118,17 @@ static int do_openat(void *cpu_env, int dirfd, const
> char *pathname, int flags,
>
> if (is_proc_myself(pathname, "exe")) {
> int execfd = qemu_getauxval(AT_EXECFD);
> - return execfd ? execfd : safe_openat(dirfd, exec_path, flags, mode);
> + if (execfd) {
> + char filename[PATH_MAX];
> + int ret;
> +
> + snprintf(filename, sizeof(filename), "/proc/self/fd/%d", execfd);
> + ret = safe_openat(dirfd, filename, flags, mode);
> + if (ret != -1) {
> + return ret;
> + }
> + }
> + return safe_openat(dirfd, exec_path, flags, mode);
> }
>
> for (fake_open = fakes; fake_open->filename; fake_open++) {
>
I think a dup() would be more appropriate, or explain why not.
Thanks,
Laurent
- Re: [PATCH v2 02/11] linux-user: Fix the execfd case of /proc/self/exe open,
Laurent Vivier <=