| Message ID | dba054de9c2285aa0908cae22ede2c082ed5af7c.1727119903.git.mvogt@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | linux-user: add openat2 support in linux-user | expand |
Le 23/09/2024 à 21:37, Michael Vogt a écrit : > This commit adds support for the `openat2()` to `QEMU_STRACE`. It > will use the `openat2.h` header if available to create user > readable flags for the `resolve` argument but does not require > the header otherwise. > > It also makes `copy_struct_from_user()` available via `qemu.h` > and `open_how_ver0` via `syscall_defs.h` so that strace.c can use > them. > > Signed-off-by: Michael Vogt <mvogt@redhat.com> > --- > linux-user/qemu.h | 9 +++++++++ > linux-user/strace.c | 40 +++++++++++++++++++++++++++++++++++++++ > linux-user/strace.list | 3 +++ > linux-user/syscall.c | 8 +------- > linux-user/syscall_defs.h | 5 +++++ > meson.build | 1 + > 6 files changed, 59 insertions(+), 7 deletions(-) > > diff --git a/linux-user/qemu.h b/linux-user/qemu.h > index 2e90a97175..98ad848ab2 100644 > --- a/linux-user/qemu.h > +++ b/linux-user/qemu.h > @@ -313,6 +313,15 @@ static inline bool access_ok(CPUState *cpu, int type, > int copy_from_user(void *hptr, abi_ulong gaddr, ssize_t len); > int copy_to_user(abi_ulong gaddr, void *hptr, ssize_t len); > > +/* > + * copy_struct_from_user() copies a target struct to a host struct, in > + * a way that guarantees backwards-compatibility for struct syscall > + * arguments. > + * > + * Similar to kernels uaccess.h:copy_struct_from_user() > + */ > +int copy_struct_from_user(void *dst, size_t ksize, abi_ptr src, size_t usize); > + > /* Functions for accessing guest memory. The tget and tput functions > read/write single values, byteswapping as necessary. The lock_user function > gets a pointer to a contiguous area of guest memory, but does not perform > diff --git a/linux-user/strace.c b/linux-user/strace.c > index b4d1098170..77d5108e5d 100644 > --- a/linux-user/strace.c > +++ b/linux-user/strace.c > @@ -13,6 +13,9 @@ > #include <linux/if_packet.h> > #include <linux/in6.h> > #include <linux/netlink.h> > +#ifdef HAVE_OPENAT2_H > +#include <linux/openat2.h> > +#endif > #include <sched.h> > #include "qemu.h" > #include "user-internals.h" > @@ -1063,6 +1066,18 @@ UNUSED static const struct flags open_flags[] = { > FLAG_END, > }; > > +UNUSED static const struct flags openat2_resolve_flags[] = { > +#ifdef HAVE_OPENAT2_H > + FLAG_GENERIC(RESOLVE_NO_XDEV), > + FLAG_GENERIC(RESOLVE_NO_MAGICLINKS), > + FLAG_GENERIC(RESOLVE_NO_SYMLINKS), > + FLAG_GENERIC(RESOLVE_BENEATH), > + FLAG_GENERIC(RESOLVE_IN_ROOT), > + FLAG_GENERIC(RESOLVE_CACHED), > +#endif > + FLAG_END, > +}; > + > UNUSED static const struct flags mount_flags[] = { > #ifdef MS_BIND > FLAG_GENERIC(MS_BIND), > @@ -3483,6 +3498,31 @@ print_openat(CPUArchState *cpu_env, const struct syscallname *name, > } > #endif > > +#ifdef TARGET_NR_openat2 > +static void > +print_openat2(CPUArchState *cpu_env, const struct syscallname *name, > + abi_long arg0, abi_long arg1, abi_long arg2, > + abi_long arg3, abi_long arg4, abi_long arg5) > +{ > + struct open_how_ver0 how = {0}; > + > + print_syscall_prologue(name); > + print_at_dirfd(arg0, 0); > + print_string(arg1, 0); > + if (copy_struct_from_user(&how, sizeof(how), arg2, arg3) == 0) { I think you need also to tswap64() all the fields of how. > + print_open_flags(how.flags, 0); > + if (how.flags & TARGET_O_CREAT) { > + print_file_mode(how.mode, 0); > + } > + print_flags(openat2_resolve_flags, how.resolve, 0); > + } else { > + print_pointer(arg2, 0); > + } > + print_raw_param("size=" TARGET_ABI_FMT_lu, arg3, 1); Why the "size="? You can write: print_raw_param(TARGET_ABI_FMT_lu, arg3, 1); Thanks, Laurent
diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 2e90a97175..98ad848ab2 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -313,6 +313,15 @@ static inline bool access_ok(CPUState *cpu, int type, int copy_from_user(void *hptr, abi_ulong gaddr, ssize_t len); int copy_to_user(abi_ulong gaddr, void *hptr, ssize_t len); +/* + * copy_struct_from_user() copies a target struct to a host struct, in + * a way that guarantees backwards-compatibility for struct syscall + * arguments. + * + * Similar to kernels uaccess.h:copy_struct_from_user() + */ +int copy_struct_from_user(void *dst, size_t ksize, abi_ptr src, size_t usize); + /* Functions for accessing guest memory. The tget and tput functions read/write single values, byteswapping as necessary. The lock_user function gets a pointer to a contiguous area of guest memory, but does not perform diff --git a/linux-user/strace.c b/linux-user/strace.c index b4d1098170..77d5108e5d 100644 --- a/linux-user/strace.c +++ b/linux-user/strace.c @@ -13,6 +13,9 @@ #include <linux/if_packet.h> #include <linux/in6.h> #include <linux/netlink.h> +#ifdef HAVE_OPENAT2_H +#include <linux/openat2.h> +#endif #include <sched.h> #include "qemu.h" #include "user-internals.h" @@ -1063,6 +1066,18 @@ UNUSED static const struct flags open_flags[] = { FLAG_END, }; +UNUSED static const struct flags openat2_resolve_flags[] = { +#ifdef HAVE_OPENAT2_H + FLAG_GENERIC(RESOLVE_NO_XDEV), + FLAG_GENERIC(RESOLVE_NO_MAGICLINKS), + FLAG_GENERIC(RESOLVE_NO_SYMLINKS), + FLAG_GENERIC(RESOLVE_BENEATH), + FLAG_GENERIC(RESOLVE_IN_ROOT), + FLAG_GENERIC(RESOLVE_CACHED), +#endif + FLAG_END, +}; + UNUSED static const struct flags mount_flags[] = { #ifdef MS_BIND FLAG_GENERIC(MS_BIND), @@ -3483,6 +3498,31 @@ print_openat(CPUArchState *cpu_env, const struct syscallname *name, } #endif +#ifdef TARGET_NR_openat2 +static void +print_openat2(CPUArchState *cpu_env, const struct syscallname *name, + abi_long arg0, abi_long arg1, abi_long arg2, + abi_long arg3, abi_long arg4, abi_long arg5) +{ + struct open_how_ver0 how = {0}; + + print_syscall_prologue(name); + print_at_dirfd(arg0, 0); + print_string(arg1, 0); + if (copy_struct_from_user(&how, sizeof(how), arg2, arg3) == 0) { + print_open_flags(how.flags, 0); + if (how.flags & TARGET_O_CREAT) { + print_file_mode(how.mode, 0); + } + print_flags(openat2_resolve_flags, how.resolve, 0); + } else { + print_pointer(arg2, 0); + } + print_raw_param("size=" TARGET_ABI_FMT_lu, arg3, 1); + print_syscall_epilogue(name); +} +#endif + #ifdef TARGET_NR_pidfd_send_signal static void print_pidfd_send_signal(CPUArchState *cpu_env, const struct syscallname *name, diff --git a/linux-user/strace.list b/linux-user/strace.list index dfd4237d14..ef658224fc 100644 --- a/linux-user/strace.list +++ b/linux-user/strace.list @@ -715,6 +715,9 @@ #ifdef TARGET_NR_openat { TARGET_NR_openat, "openat" , NULL, print_openat, NULL }, #endif +#ifdef TARGET_NR_openat2 +{ TARGET_NR_openat2, "openat2" , NULL, print_openat2, NULL }, +#endif #ifdef TARGET_NR_osf_adjtime { TARGET_NR_osf_adjtime, "osf_adjtime" , NULL, NULL, NULL }, #endif diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 8c5d68ef85..b7a0ee67cd 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -608,8 +608,7 @@ static int check_zeroed_user(abi_long addr, size_t ksize, size_t usize) * * Similar to kernels uaccess.h:copy_struct_from_user() */ -static int -copy_struct_from_user(void *dst, size_t ksize, abi_ptr src, size_t usize) +int copy_struct_from_user(void *dst, size_t ksize, abi_ptr src, size_t usize) { size_t size = MIN(ksize, usize); size_t rest = MAX(ksize, usize) - size; @@ -682,11 +681,6 @@ safe_syscall3(ssize_t, write, int, fd, const void *, buff, size_t, count) safe_syscall4(int, openat, int, dirfd, const char *, pathname, \ int, flags, mode_t, mode) -struct open_how_ver0 { - __u64 flags; - __u64 mode; - __u64 resolve; -}; safe_syscall4(int, openat2, int, dirfd, const char *, pathname, \ const struct open_how_ver0 *, how, size_t, size) diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h index 9a2f2ef8f7..4eea4039c3 100644 --- a/linux-user/syscall_defs.h +++ b/linux-user/syscall_defs.h @@ -2754,6 +2754,11 @@ struct target_sched_param { }; /* from kernel's include/uapi/linux/openat2.h */ +struct open_how_ver0 { + __u64 flags; + __u64 mode; + __u64 resolve; +}; struct target_open_how_ver0 { abi_ullong flags; abi_ullong mode; diff --git a/meson.build b/meson.build index 10464466ff..77cb5c41d8 100644 --- a/meson.build +++ b/meson.build @@ -2488,6 +2488,7 @@ config_host_data.set('CONFIG_LINUX_MAGIC_H', cc.has_header('linux/magic.h')) config_host_data.set('CONFIG_VALGRIND_H', cc.has_header('valgrind/valgrind.h')) config_host_data.set('HAVE_BTRFS_H', cc.has_header('linux/btrfs.h')) config_host_data.set('HAVE_DRM_H', cc.has_header('libdrm/drm.h')) +config_host_data.set('HAVE_OPENAT2_H', cc.has_header('linux/openat2.h')) config_host_data.set('HAVE_PTY_H', cc.has_header('pty.h')) config_host_data.set('HAVE_SYS_DISK_H', cc.has_header('sys/disk.h')) config_host_data.set('HAVE_SYS_IOCCOM_H', cc.has_header('sys/ioccom.h'))
This commit adds support for the `openat2()` to `QEMU_STRACE`. It will use the `openat2.h` header if available to create user readable flags for the `resolve` argument but does not require the header otherwise. It also makes `copy_struct_from_user()` available via `qemu.h` and `open_how_ver0` via `syscall_defs.h` so that strace.c can use them. Signed-off-by: Michael Vogt <mvogt@redhat.com> --- linux-user/qemu.h | 9 +++++++++ linux-user/strace.c | 40 +++++++++++++++++++++++++++++++++++++++ linux-user/strace.list | 3 +++ linux-user/syscall.c | 8 +------- linux-user/syscall_defs.h | 5 +++++ meson.build | 1 + 6 files changed, 59 insertions(+), 7 deletions(-)