* [Qemu-devel] [PATCH] linux-user: identify running binary in /proc/$$/exe @ 2013-03-11 17:19 Andreas Schwab 2013-04-18 14:56 ` Peter Maydell 0 siblings, 1 reply; 4+ messages in thread From: Andreas Schwab @ 2013-03-11 17:19 UTC (permalink / raw) To: qemu-devel Some applications like to test /proc/$$/exe (where $$ is the own pid) to find out who they are. Handle it like /proc/self/exe. Also, do the same handling in readlinkat. Signed-off-by: Andreas Schwab <schwab@suse.de> --- linux-user/syscall.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 19630ea..3e5a6ae 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -6413,7 +6413,10 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, if (!p || !p2) ret = -TARGET_EFAULT; else { - if (strncmp((const char *)p, "/proc/self/exe", 14) == 0) { + char myself[PATH_MAX]; + snprintf(myself, sizeof(myself), "/proc/%d/exe", getpid()); + if (strncmp((const char *)p, "/proc/self/exe", 14) == 0 || + strcmp((const char *)p, myself) == 0) { char real[PATH_MAX]; temp = realpath(exec_path,real); ret = (temp==NULL) ? get_errno(-1) : strlen(real) ; @@ -6429,13 +6432,24 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, #if defined(TARGET_NR_readlinkat) && defined(__NR_readlinkat) case TARGET_NR_readlinkat: { - void *p2; + void *p2, *temp; p = lock_user_string(arg2); p2 = lock_user(VERIFY_WRITE, arg3, arg4, 0); if (!p || !p2) ret = -TARGET_EFAULT; - else - ret = get_errno(sys_readlinkat(arg1, path(p), p2, arg4)); + else { + char myself[PATH_MAX]; + snprintf(myself, sizeof(myself), "/proc/%d/exe", getpid()); + if (strncmp((const char *)p, "/proc/self/exe", 14) == 0 || + strcmp((const char *)p, myself) == 0) { + char real[PATH_MAX]; + temp = realpath(exec_path,real); + ret = (temp==NULL) ? get_errno(-1) : strlen(real) ; + snprintf((char *)p2, arg3, "%s", real); + } + else + ret = get_errno(sys_readlinkat(arg1, path(p), p2, arg4)); + } unlock_user(p2, arg3, ret); unlock_user(p, arg2, 0); } -- 1.8.1.5 -- Andreas Schwab, SUSE Labs, schwab@suse.de GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7 "And now for something completely different." ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH] linux-user: identify running binary in /proc/$$/exe 2013-03-11 17:19 [Qemu-devel] [PATCH] linux-user: identify running binary in /proc/$$/exe Andreas Schwab @ 2013-04-18 14:56 ` Peter Maydell 2013-05-08 10:31 ` [Qemu-devel] [PATCH] linux-user: handle /proc/$$ like /proc/self Andreas Schwab 0 siblings, 1 reply; 4+ messages in thread From: Peter Maydell @ 2013-04-18 14:56 UTC (permalink / raw) To: Andreas Schwab; +Cc: qemu-devel On 11 March 2013 17:19, Andreas Schwab <schwab@suse.de> wrote: > Some applications like to test /proc/$$/exe (where $$ is the own pid) to > find out who they are. Handle it like /proc/self/exe. > > Also, do the same handling in readlinkat. Sorry I didn't get round to reviewing this earlier; I think it slipped through the cracks :-( > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index 19630ea..3e5a6ae 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -6413,7 +6413,10 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, > if (!p || !p2) > ret = -TARGET_EFAULT; > else { > - if (strncmp((const char *)p, "/proc/self/exe", 14) == 0) { > + char myself[PATH_MAX]; > + snprintf(myself, sizeof(myself), "/proc/%d/exe", getpid()); > + if (strncmp((const char *)p, "/proc/self/exe", 14) == 0 || > + strcmp((const char *)p, myself) == 0) { > char real[PATH_MAX]; > temp = realpath(exec_path,real); > ret = (temp==NULL) ? get_errno(-1) : strlen(real) ; > @@ -6429,13 +6432,24 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, > #if defined(TARGET_NR_readlinkat) && defined(__NR_readlinkat) > case TARGET_NR_readlinkat: > { > - void *p2; > + void *p2, *temp; > p = lock_user_string(arg2); > p2 = lock_user(VERIFY_WRITE, arg3, arg4, 0); > if (!p || !p2) > ret = -TARGET_EFAULT; > - else > - ret = get_errno(sys_readlinkat(arg1, path(p), p2, arg4)); You could add braces on the 'then' part of this if() and get rid of the stray hardcoded tab in the existing code. (not a requirement but since we're in the area anyway...) > + else { > + char myself[PATH_MAX]; > + snprintf(myself, sizeof(myself), "/proc/%d/exe", getpid()); > + if (strncmp((const char *)p, "/proc/self/exe", 14) == 0 || > + strcmp((const char *)p, myself) == 0) { > + char real[PATH_MAX]; > + temp = realpath(exec_path,real); > + ret = (temp==NULL) ? get_errno(-1) : strlen(real) ; > + snprintf((char *)p2, arg3, "%s", real); This seems to be a fair chunk of code in common with the readlink case above -- can we abstract it out? (ideally to a function somewhere in the same area of this file as the code that handles intercepting /proc/ calls for open().) It would be consistent to support /proc/$$/ for all the open() intercepts too. > + } > + else > + ret = get_errno(sys_readlinkat(arg1, path(p), p2, arg4)); > + } > unlock_user(p2, arg3, ret); > unlock_user(p, arg2, 0); > } > -- > 1.8.1.5 thanks -- PMM ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Qemu-devel] [PATCH] linux-user: handle /proc/$$ like /proc/self 2013-04-18 14:56 ` Peter Maydell @ 2013-05-08 10:31 ` Andreas Schwab 2013-06-27 17:09 ` Peter Maydell 0 siblings, 1 reply; 4+ messages in thread From: Andreas Schwab @ 2013-05-08 10:31 UTC (permalink / raw) To: Peter Maydell; +Cc: qemu-devel Some applications use /proc/$$/... (where $$ is the own pid) instead of /proc/self/... to refer to their own proc files. Extend the interception for open and readlink to handle this case. Also, do the same interception in readlinkat. Signed-off-by: Andreas Schwab <schwab@suse.de> --- linux-user/syscall.c | 63 +++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 45 insertions(+), 18 deletions(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 84dfbf5..d5db6bf 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -5157,6 +5157,30 @@ static int open_self_auxv(void *cpu_env, int fd) return 0; } +static int is_proc_myself(const char *filename, const char *entry) +{ + if (!strncmp(filename, "/proc/", strlen("/proc/"))) { + filename += strlen("/proc/"); + if (!strncmp(filename, "self/", strlen("self/"))) { + filename += strlen("self/"); + } else if (*filename >= '1' && *filename <= '9') { + char myself[80]; + snprintf(myself, sizeof(myself), "%d/", getpid()); + if (!strncmp(filename, myself, strlen(myself))) { + filename += strlen(myself); + } else { + return 0; + } + } else { + return 0; + } + if (!strcmp(filename, entry)) { + return 1; + } + } + return 0; +} + static int do_open(void *cpu_env, const char *pathname, int flags, mode_t mode) { struct fake_open { @@ -5165,15 +5189,14 @@ static int do_open(void *cpu_env, const char *pathname, int flags, mode_t mode) }; const struct fake_open *fake_open; static const struct fake_open fakes[] = { - { "/proc/self/maps", open_self_maps }, - { "/proc/self/stat", open_self_stat }, - { "/proc/self/auxv", open_self_auxv }, + { "maps", open_self_maps }, + { "stat", open_self_stat }, + { "auxv", open_self_auxv }, { NULL, NULL } }; for (fake_open = fakes; fake_open->filename; fake_open++) { - if (!strncmp(pathname, fake_open->filename, - strlen(fake_open->filename))) { + if (is_proc_myself(pathname, fake_open->filename)) { break; } } @@ -6468,20 +6491,18 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, #endif case TARGET_NR_readlink: { - void *p2, *temp; + void *p2; p = lock_user_string(arg1); p2 = lock_user(VERIFY_WRITE, arg2, arg3, 0); - if (!p || !p2) + if (!p || !p2) { ret = -TARGET_EFAULT; - else { - if (strncmp((const char *)p, "/proc/self/exe", 14) == 0) { - char real[PATH_MAX]; - temp = realpath(exec_path,real); - ret = (temp==NULL) ? get_errno(-1) : strlen(real) ; - snprintf((char *)p2, arg3, "%s", real); - } - else - ret = get_errno(readlink(path(p), p2, arg3)); + } else if (is_proc_myself((const char *)p, "exe")) { + char real[PATH_MAX], *temp; + temp = realpath(exec_path, real); + ret = temp == NULL ? get_errno(-1) : strlen(real) ; + snprintf((char *)p2, arg3, "%s", real); + } else { + ret = get_errno(readlink(path(p), p2, arg3)); } unlock_user(p2, arg2, ret); unlock_user(p, arg1, 0); @@ -6493,10 +6514,16 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, void *p2; p = lock_user_string(arg2); p2 = lock_user(VERIFY_WRITE, arg3, arg4, 0); - if (!p || !p2) + if (!p || !p2) { ret = -TARGET_EFAULT; - else + } else if (is_proc_myself((const char *)p, "exe")) { + char real[PATH_MAX], *temp; + temp = realpath(exec_path, real); + ret = temp == NULL ? get_errno(-1) : strlen(real) ; + snprintf((char *)p2, arg4, "%s", real); + } else { ret = get_errno(sys_readlinkat(arg1, path(p), p2, arg4)); + } unlock_user(p2, arg3, ret); unlock_user(p, arg2, 0); } -- 1.8.2.2 -- Andreas Schwab, SUSE Labs, schwab@suse.de GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7 "And now for something completely different." ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH] linux-user: handle /proc/$$ like /proc/self 2013-05-08 10:31 ` [Qemu-devel] [PATCH] linux-user: handle /proc/$$ like /proc/self Andreas Schwab @ 2013-06-27 17:09 ` Peter Maydell 0 siblings, 0 replies; 4+ messages in thread From: Peter Maydell @ 2013-06-27 17:09 UTC (permalink / raw) To: Andreas Schwab; +Cc: Riku Voipio, qemu-devel On 8 May 2013 11:31, Andreas Schwab <schwab@suse.de> wrote: > Some applications use /proc/$$/... (where $$ is the own pid) instead of > /proc/self/... to refer to their own proc files. Extend the interception > for open and readlink to handle this case. Also, do the same interception > in readlinkat. > > Signed-off-by: Andreas Schwab <schwab@suse.de> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> (assuming the necessary fixups post-rebase.) -- PMM ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-06-27 17:09 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2013-03-11 17:19 [Qemu-devel] [PATCH] linux-user: identify running binary in /proc/$$/exe Andreas Schwab 2013-04-18 14:56 ` Peter Maydell 2013-05-08 10:31 ` [Qemu-devel] [PATCH] linux-user: handle /proc/$$ like /proc/self Andreas Schwab 2013-06-27 17:09 ` Peter Maydell
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