| Message ID | 20160914202008.14119-4-aleksandar.markovic@rt-rk.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Le 14/09/2016 à 22:19, Aleksandar Markovic a écrit : > From: Aleksandar Markovic <aleksandar.markovic@imgtec.com> > > This patch implements Qemu user mode sysfs() syscall support. > > Syscall sysfs() involves returning information about the filesystem types > currently present in the kernel, and can operate in three distinct flavors, > depending on its first argument. > > The implementation is based on invocation of host's sysfs(), and > its key part is in the correspondent case segment of the main switch > statement of the function do_syscall(), in file linux-user/syscalls.c. > All necessary conversions of data structures from target to host and from > host to target are covered. Based on the value of the first argument, three > cases are distinguished, and such conversions are implemented separately > for each case. Relevant support for "-strace" option is included in files > linux-user/strace.c and linux-user/strace.list. > > This patch also fixes failures of LTP tests sysfs01, sysfs02, sysfs03, > sysfs04, sysfs05, and sysfs06, if executed in Qemu user mode. > > Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> > --- > linux-user/strace.c | 25 +++++++++++++++++++++++++ > linux-user/strace.list | 2 +- > linux-user/syscall.c | 42 +++++++++++++++++++++++++++++++++++++++++- > 3 files changed, 67 insertions(+), 2 deletions(-) > > diff --git a/linux-user/strace.c b/linux-user/strace.c > index 4524c70..61911e7 100644 > --- a/linux-user/strace.c > +++ b/linux-user/strace.c > @@ -2151,6 +2151,31 @@ print_kill(const struct syscallname *name, > } > #endif > > +#if defined(TARGET_NR_sysfs) > +static void > +print_sysfs(const struct syscallname *name, > + abi_long arg0, abi_long arg1, abi_long arg2, > + abi_long arg3, abi_long arg4, abi_long arg5) > +{ > + print_syscall_prologue(name); perhaps you can move here: print_raw_param("%d", arg0, 0); > + switch (arg0) { > + case 1: > + print_raw_param("%d", arg0, 1); should be ", 0);" > + print_string(arg1, 1); > + break; > + case 2: > + print_raw_param("%d", arg0, 0); > + print_raw_param("%u", arg1, 0); > + print_pointer(arg2, 1); > + break; > + default: > + print_raw_param("%d", arg0, 1); > + break; in syscall.c, you use 3 for this, and default is EINVAL. > + } > + print_syscall_epilogue(name); > +} > +#endif > + > /* > * An array of all of the syscalls we know about > */ > diff --git a/linux-user/strace.list b/linux-user/strace.list > index 00b2e9b..0bf1bea 100644 > --- a/linux-user/strace.list > +++ b/linux-user/strace.list > @@ -1371,7 +1371,7 @@ > { TARGET_NR_sys_epoll_wait, "sys_epoll_wait" , NULL, NULL, NULL }, > #endif > #ifdef TARGET_NR_sysfs > -{ TARGET_NR_sysfs, "sysfs" , NULL, NULL, NULL }, > +{ TARGET_NR_sysfs, "sysfs" , NULL, print_sysfs, NULL }, > #endif > #ifdef TARGET_NR_sysinfo > { TARGET_NR_sysinfo, "sysinfo" , NULL, NULL, NULL }, > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index eab9207..3436ee6 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -9549,7 +9549,47 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, > #endif > #ifdef TARGET_NR_sysfs > case TARGET_NR_sysfs: > - goto unimplemented; > + switch (arg1) { > + case 1: > + { > + if (arg2 != 0) { "arg2 == NULL" will be managed by lock_user_string() > + p = lock_user_string(arg2); > + if (!p) { > + goto efault; > + } > + ret = get_errno(syscall(__NR_sysfs, arg1, p)); > + unlock_user(p, arg2, 0); > + } else { > + ret = get_errno(syscall(__NR_sysfs, arg1, NULL)); why? > + } > + } > + break; > + case 2: > + { > + if (arg3 != 0) { > + char buf[PATH_MAX]; PATH_MAX (4096) should be a little bit excessive for a filesystem name. they have rarely more than 16 characters. > + int len; > + memset(buf, 0, PATH_MAX); > + ret = get_errno(syscall(__NR_sysfs, arg1, arg2, buf)); > + len = PATH_MAX; > + if (len > strlen(buf)) { > + len = strlen(buf); > + } > + if (copy_to_user(arg3, buf, len) != 0) { > + goto efault; > + } > + } else { > + ret = get_errno(syscall(__NR_sysfs, arg1, arg2, NULL)); Why? just let the copy_to_user() trigger the "goto efault" in the case of arg3 == 0. > + } > + } > + break; > + case 3: > + ret = get_errno(syscall(__NR_sysfs, arg1)); > + break; > + default: > + ret = -EINVAL; > + } > + break; > #endif > case TARGET_NR_personality: > ret = get_errno(personality(arg1)); >
diff --git a/linux-user/strace.c b/linux-user/strace.c index 4524c70..61911e7 100644 --- a/linux-user/strace.c +++ b/linux-user/strace.c @@ -2151,6 +2151,31 @@ print_kill(const struct syscallname *name, } #endif +#if defined(TARGET_NR_sysfs) +static void +print_sysfs(const struct syscallname *name, + abi_long arg0, abi_long arg1, abi_long arg2, + abi_long arg3, abi_long arg4, abi_long arg5) +{ + print_syscall_prologue(name); + switch (arg0) { + case 1: + print_raw_param("%d", arg0, 1); + print_string(arg1, 1); + break; + case 2: + print_raw_param("%d", arg0, 0); + print_raw_param("%u", arg1, 0); + print_pointer(arg2, 1); + break; + default: + print_raw_param("%d", arg0, 1); + break; + } + print_syscall_epilogue(name); +} +#endif + /* * An array of all of the syscalls we know about */ diff --git a/linux-user/strace.list b/linux-user/strace.list index 00b2e9b..0bf1bea 100644 --- a/linux-user/strace.list +++ b/linux-user/strace.list @@ -1371,7 +1371,7 @@ { TARGET_NR_sys_epoll_wait, "sys_epoll_wait" , NULL, NULL, NULL }, #endif #ifdef TARGET_NR_sysfs -{ TARGET_NR_sysfs, "sysfs" , NULL, NULL, NULL }, +{ TARGET_NR_sysfs, "sysfs" , NULL, print_sysfs, NULL }, #endif #ifdef TARGET_NR_sysinfo { TARGET_NR_sysinfo, "sysinfo" , NULL, NULL, NULL }, diff --git a/linux-user/syscall.c b/linux-user/syscall.c index eab9207..3436ee6 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -9549,7 +9549,47 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, #endif #ifdef TARGET_NR_sysfs case TARGET_NR_sysfs: - goto unimplemented; + switch (arg1) { + case 1: + { + if (arg2 != 0) { + p = lock_user_string(arg2); + if (!p) { + goto efault; + } + ret = get_errno(syscall(__NR_sysfs, arg1, p)); + unlock_user(p, arg2, 0); + } else { + ret = get_errno(syscall(__NR_sysfs, arg1, NULL)); + } + } + break; + case 2: + { + if (arg3 != 0) { + char buf[PATH_MAX]; + int len; + memset(buf, 0, PATH_MAX); + ret = get_errno(syscall(__NR_sysfs, arg1, arg2, buf)); + len = PATH_MAX; + if (len > strlen(buf)) { + len = strlen(buf); + } + if (copy_to_user(arg3, buf, len) != 0) { + goto efault; + } + } else { + ret = get_errno(syscall(__NR_sysfs, arg1, arg2, NULL)); + } + } + break; + case 3: + ret = get_errno(syscall(__NR_sysfs, arg1)); + break; + default: + ret = -EINVAL; + } + break; #endif case TARGET_NR_personality: ret = get_errno(personality(arg1));