diff options
| -rw-r--r-- | Documentation/core-api/printk-formats.rst | 12 | ||||
| -rw-r--r-- | include/linux/errname.h | 16 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 9 | ||||
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/errname.c | 223 | ||||
| -rw-r--r-- | lib/test_printf.c | 21 | ||||
| -rw-r--r-- | lib/vsprintf.c | 27 |
7 files changed, 309 insertions, 0 deletions
diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst index 75d2bbe9813f..dffd5c0b24f8 100644 --- a/Documentation/core-api/printk-formats.rst +++ b/Documentation/core-api/printk-formats.rst @@ -79,6 +79,18 @@ has the added benefit of providing a unique identifier. On 64-bit machines the first 32 bits are zeroed. The kernel will print ``(ptrval)`` until it gathers enough entropy. If you *really* want the address see %px below. +Error Pointers +-------------- + +:: + + %pe -ENOSPC + +For printing error pointers (i.e. a pointer for which IS_ERR() is true) +as a symbolic error name. Error values for which no symbolic name is +known are printed in decimal, while a non-ERR_PTR passed as the +argument to %pe gets treated as ordinary %p. + Symbols/Function Pointers ------------------------- diff --git a/include/linux/errname.h b/include/linux/errname.h new file mode 100644 index 000000000000..e8576ad90cb7 --- /dev/null +++ b/include/linux/errname.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_ERRNAME_H +#define _LINUX_ERRNAME_H + +#include <linux/stddef.h> + +#ifdef CONFIG_SYMBOLIC_ERRNAME +const char *errname(int err); +#else +static inline const char *errname(int err) +{ + return NULL; +} +#endif + +#endif /* _LINUX_ERRNAME_H */ diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 06d9c9d70385..4934b69c7b39 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -164,6 +164,15 @@ config DYNAMIC_DEBUG See Documentation/admin-guide/dynamic-debug-howto.rst for additional information. +config SYMBOLIC_ERRNAME + bool "Support symbolic error names in printf" + default y if PRINTK + help + If you say Y here, the kernel's printf implementation will + be able to print symbolic error names such as ENOSPC instead + of the number 28. It makes the kernel image slightly larger + (about 3KB), but can make the kernel logs easier to read. + endmenu # "printk and dmesg options" menu "Compile-time checks and compiler options" diff --git a/lib/Makefile b/lib/Makefile index d3daedf93c5a..907759f28916 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -183,6 +183,7 @@ lib-$(CONFIG_GENERIC_BUG) += bug.o obj-$(CONFIG_HAVE_ARCH_TRACEHOOK) += syscall.o obj-$(CONFIG_DYNAMIC_DEBUG) += dynamic_debug.o +obj-$(CONFIG_SYMBOLIC_ERRNAME) += errname.o obj-$(CONFIG_NLATTR) += nlattr.o diff --git a/lib/errname.c b/lib/errname.c new file mode 100644 index 000000000000..0c4d3e66170e --- /dev/null +++ b/lib/errname.c @@ -0,0 +1,223 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/build_bug.h> +#include <linux/errno.h> +#include <linux/errname.h> +#include <linux/kernel.h> + +/* + * Ensure these tables do not accidentally become gigantic if some + * huge errno makes it in. On most architectures, the first table will + * only have about 140 entries, but mips and parisc have more sparsely + * allocated errnos (with EHWPOISON = 257 on parisc, and EDQUOT = 1133 + * on mips), so this wastes a bit of space on those - though we + * special case the EDQUOT case. + */ +#define E(err) [err + BUILD_BUG_ON_ZERO(err <= 0 || err > 300)] = "-" #err +static const char *names_0[] = { + E(E2BIG), + E(EACCES), + E(EADDRINUSE), + E(EADDRNOTAVAIL), + E(EADV), + E(EAFNOSUPPORT), + E(EALREADY), + E(EBADE), + E(EBADF), + E(EBADFD), + E(EBADMSG), + E(EBADR), + E(EBADRQC), + E(EBADSLT), + E(EBFONT), + E(EBUSY), +#ifdef ECANCELLED + E(ECANCELLED), +#endif + E(ECHILD), + E(ECHRNG), + E(ECOMM), + E(ECONNABORTED), + E(ECONNRESET), + E(EDEADLOCK), + E(EDESTADDRREQ), + E(EDOM), + E(EDOTDOT), +#ifndef CONFIG_MIPS + E(EDQUOT), +#endif + E(EEXIST), + E(EFAULT), + E(EFBIG), + E(EHOSTDOWN), + E(EHOSTUNREACH), + E(EHWPOISON), + E(EIDRM), + E(EILSEQ), +#ifdef EINIT + E(EINIT), +#endif + E(EINPROGRESS), + E(EINTR), + E(EINVAL), + E(EIO), + E(EISCONN), + E(EISDIR), + E(EISNAM), + E(EKEYEXPIRED), + E(EKEYREJECTED), + E(EKEYREVOKED), + E(EL2HLT), + E(EL2NSYNC), + E(EL3HLT), + E(EL3RST), + E(ELIBACC), + E(ELIBBAD), + E(ELIBEXEC), + E(ELIBMAX), + E(ELIBSCN), + E(ELNRNG), + E(ELOOP), + E(EMEDIUMTYPE), + E(EMFILE), + E(EMLINK), + E(EMSGSIZE), + E(EMULTIHOP), + E(ENAMETOOLONG), + E(ENAVAIL), + E(ENETDOWN), + E(ENETRESET), + E(ENETUNREACH), + E(ENFILE), + E(ENOANO), + E(ENOBUFS), + E(ENOCSI), + E(ENODATA), + E(ENODEV), + E(ENOENT), + E(ENOEXEC), + E(ENOKEY), + E(ENOLCK), + E(ENOLINK), + E(ENOMEDIUM), + E(ENOMEM), + E(ENOMSG), + E(ENONET), + E(ENOPKG), + E(ENOPROTOOPT), + E(ENOSPC), + E(ENOSR), + E(ENOSTR), +#ifdef ENOSYM + E(ENOSYM), +#endif + E(ENOSYS), + E(ENOTBLK), + E(ENOTCONN), + E(ENOTDIR), + E(ENOTEMPTY), + E(ENOTNAM), + E(ENOTRECOVERABLE), + E(ENOTSOCK), + E(ENOTTY), + E(ENOTUNIQ), + E(ENXIO), + E(EOPNOTSUPP), + E(EOVERFLOW), + E(EOWNERDEAD), + E(EPERM), + E(EPFNOSUPPORT), + E(EPIPE), +#ifdef EPROCLIM + E(EPROCLIM), +#endif + E(EPROTO), + E(EPROTONOSUPPORT), + E(EPROTOTYPE), + E(ERANGE), + E(EREMCHG), +#ifdef EREMDEV + E(EREMDEV), +#endif + E(EREMOTE), + E(EREMOTEIO), +#ifdef EREMOTERELEASE + E(EREMOTERELEASE), +#endif + E(ERESTART), + E(ERFKILL), + E(EROFS), +#ifdef ERREMOTE + E(ERREMOTE), +#endif + E(ESHUTDOWN), + E(ESOCKTNOSUPPORT), + E(ESPIPE), + E(ESRCH), + E(ESRMNT), + E(ESTALE), + E(ESTRPIPE), + E(ETIME), + E(ETIMEDOUT), + E(ETOOMANYREFS), + E(ETXTBSY), + E(EUCLEAN), + E(EUNATCH), + E(EUSERS), + E(EXDEV), + E(EXFULL), + + E(ECANCELED), /* ECANCELLED */ + E(EAGAIN), /* EWOULDBLOCK */ + E(ECONNREFUSED), /* EREFUSED */ + E(EDEADLK), /* EDEADLOCK */ +}; +#undef E + +#define E(err) [err - 512 + BUILD_BUG_ON_ZERO(err < 512 || err > 550)] = "-" #err +static const char *names_512[] = { + E(ERESTARTSYS), + E(ERESTARTNOINTR), + E(ERESTARTNOHAND), + E(ENOIOCTLCMD), + E(ERESTART_RESTARTBLOCK), + E(EPROBE_DEFER), + E(EOPENSTALE), + E(ENOPARAM), + + E(EBADHANDLE), + E(ENOTSYNC), + E(EBADCOOKIE), + E(ENOTSUPP), + E(ETOOSMALL), + E(ESERVERFAULT), + E(EBADTYPE), + E(EJUKEBOX), + E(EIOCBQUEUED), + E(ERECALLCONFLICT), +}; +#undef E + +static const char *__errname(unsigned err) +{ + if (err < ARRAY_SIZE(names_0)) + return names_0[err]; + if (err >= 512 && err - 512 < ARRAY_SIZE(names_512)) + return names_512[err - 512]; + /* But why? */ + if (IS_ENABLED(CONFIG_MIPS) && err == EDQUOT) /* 1133 */ + return "-EDQUOT"; + return NULL; +} + +/* + * errname(EIO) -> "EIO" + * errname(-EIO) -> "-EIO" + */ +const char *errname(int err) +{ + const char *name = __errname(abs(err)); + if (!name) + return NULL; + + return err > 0 ? name + 1 : name; +} diff --git a/lib/test_printf.c b/lib/test_printf.c index 5d94cbff2120..030daeb4fe21 100644 --- a/lib/test_printf.c +++ b/lib/test_printf.c @@ -594,6 +594,26 @@ flags(void) } static void __init +errptr(void) +{ + test("-1234", "%pe", ERR_PTR(-1234)); + + /* Check that %pe with a non-ERR_PTR gets treated as ordinary %p. */ + BUILD_BUG_ON(IS_ERR(PTR)); + test_hashed("%pe", PTR); + +#ifdef CONFIG_SYMBOLIC_ERRNAME + test("(-ENOTSOCK)", "(%pe)", ERR_PTR(-ENOTSOCK)); + test("(-EAGAIN)", "(%pe)", ERR_PTR(-EAGAIN)); + BUILD_BUG_ON(EAGAIN != EWOULDBLOCK); + test("(-EAGAIN)", "(%pe)", ERR_PTR(-EWOULDBLOCK)); + test("[-EIO ]", "[%-8pe]", ERR_PTR(-EIO)); + test("[ -EIO]", "[%8pe]", ERR_PTR(-EIO)); + test("-EPROBE_DEFER", "%pe", ERR_PTR(-EPROBE_DEFER)); +#endif +} + +static void __init test_pointer(void) { plain(); @@ -615,6 +635,7 @@ test_pointer(void) bitmap(); netdev_features(); flags(); + errptr(); } static void __init selftest(void) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index e78017a3e1bd..b54d252b398e 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -21,6 +21,7 @@ #include <linux/build_bug.h> #include <linux/clk.h> #include <linux/clk-provider.h> +#include <linux/errname.h> #include <linux/module.h> /* for KSYM_SYMBOL_LEN */ #include <linux/types.h> #include <linux/string.h> @@ -613,6 +614,25 @@ static char *string_nocheck(char *buf, char *end, const char *s, return widen_string(buf, len, end, spec); } +static char *err_ptr(char *buf, char *end, void *ptr, + struct printf_spec spec) +{ + int err = PTR_ERR(ptr); + const char *sym = errname(err); + + if (sym) + return string_nocheck(buf, end, sym, spec); + + /* + * Somebody passed ERR_PTR(-1234) or some other non-existing + * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to + * printing it as its decimal representation. + */ + spec.flags |= SIGN; + spec.base = 10; + return number(buf, end, err, spec); +} + /* Be careful: error messages must fit into the given buffer. */ static char *error_string(char *buf, char *end, const char *s, struct printf_spec spec) @@ -2187,6 +2207,11 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, return kobject_string(buf, end, ptr, spec, fmt); case 'x': return pointer_string(buf, end, ptr, spec); + case 'e': + /* %pe with a non-ERR_PTR gets treated as plain %p */ + if (!IS_ERR(ptr)) + break; + return err_ptr(buf, end, ptr, spec); } /* default is to _not_ leak addresses, hash before printing */ @@ -2823,6 +2848,7 @@ int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) case 'f': case 'x': case 'K': + case 'e': save_arg(void *); break; default: @@ -2999,6 +3025,7 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) case 'f': case 'x': case 'K': + case 'e': process = true; break; default: |