public inbox for newlib-cvs@sourceware.org help / color / mirror / Atom feed
From: Corinna Vinschen <corinna@sourceware.org> To: newlib-cvs@sourceware.org Subject: [newlib-cygwin/main] ssp: add support for _FORTIFY_SOURCE=3 Date: Mon, 29 Jan 2024 15:29:01 +0000 (GMT) [thread overview] Message-ID: <20240129152901.47F4F385840B@sourceware.org> (raw) https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=497e6eb2c0fadd0d4cb4ed418642832b020b19d4 commit 497e6eb2c0fadd0d4cb4ed418642832b020b19d4 Author: Christian Franke <christian.franke@t-online.de> AuthorDate: Fri Jan 26 17:20:37 2024 +0100 Commit: Corinna Vinschen <corinna@vinschen.de> CommitDate: Mon Jan 29 14:03:37 2024 +0100 ssp: add support for _FORTIFY_SOURCE=3 If specified, use __builtin_dynamic_object_size() instead of __builtin_object_size() if supported (GCC 12.0 or later). This enables buffer overflow checks if the buffer size is non-const but known during runtime. Use new macro __ssp_bos_known() instead of the (bos(p) != (size_t)-1) checks. The latter is no longer a compile time constant in all cases. This avoids the generation of unused code. Signed-off-by: Christian Franke <christian.franke@t-online.de> Diff: --- newlib/libc/include/ssp/ssp.h | 11 ++++++++++- newlib/libc/include/ssp/string.h | 4 ++-- newlib/libc/include/ssp/strings.h | 4 ++-- newlib/libc/include/sys/features.h | 12 +++++++++--- 4 files changed, 23 insertions(+), 8 deletions(-) diff --git a/newlib/libc/include/ssp/ssp.h b/newlib/libc/include/ssp/ssp.h index 9229086599e9..49ea5f2dd8a4 100644 --- a/newlib/libc/include/ssp/ssp.h +++ b/newlib/libc/include/ssp/ssp.h @@ -43,11 +43,20 @@ #define __ssp_inline extern __inline__ __attribute__((__always_inline__, __gnu_inline__)) +#if __SSP_FORTIFY_LEVEL > 2 +#define __ssp_bos(ptr) __builtin_dynamic_object_size(ptr, 1) +#define __ssp_bos0(ptr) __builtin_dynamic_object_size(ptr, 0) +#define __ssp_bos_known(ptr) \ + (__builtin_object_size(ptr, 0) != (size_t)-1 \ + || !__builtin_constant_p(__ssp_bos(ptr))) +#else #define __ssp_bos(ptr) __builtin_object_size(ptr, __SSP_FORTIFY_LEVEL > 1) #define __ssp_bos0(ptr) __builtin_object_size(ptr, 0) +#define __ssp_bos_known(ptr) (__ssp_bos0(ptr) != (size_t)-1) +#endif #define __ssp_check(buf, len, bos) \ - if (bos(buf) != (size_t)-1 && len > bos(buf)) \ + if (__ssp_bos_known(buf) && len > bos(buf)) \ __chk_fail() #define __ssp_decl(rtype, fun, args) \ rtype __ssp_real_(fun) args __asm__(__ASMNAME(#fun)); \ diff --git a/newlib/libc/include/ssp/string.h b/newlib/libc/include/ssp/string.h index 85c4512acfd3..22b52097cb9b 100644 --- a/newlib/libc/include/ssp/string.h +++ b/newlib/libc/include/ssp/string.h @@ -49,12 +49,12 @@ __END_DECLS #if __SSP_FORTIFY_LEVEL > 0 #define __ssp_bos_check3(fun, dst, src, len) \ - ((__ssp_bos0(dst) != (size_t)-1) ? \ + (__ssp_bos_known(dst) ? \ __builtin___ ## fun ## _chk(dst, src, len, __ssp_bos0(dst)) : \ __ ## fun ## _ichk(dst, src, len)) #define __ssp_bos_check2(fun, dst, src) \ - ((__ssp_bos0(dst) != (size_t)-1) ? \ + (__ssp_bos_known(dst) ? \ __builtin___ ## fun ## _chk(dst, src, __ssp_bos0(dst)) : \ __ ## fun ## _ichk(dst, src)) diff --git a/newlib/libc/include/ssp/strings.h b/newlib/libc/include/ssp/strings.h index 13adba175276..be59882ebc0b 100644 --- a/newlib/libc/include/ssp/strings.h +++ b/newlib/libc/include/ssp/strings.h @@ -37,11 +37,11 @@ #if __BSD_VISIBLE || __POSIX_VISIBLE <= 200112 #define bcopy(src, dst, len) \ - ((__ssp_bos0(dst) != (size_t)-1) ? \ + (__ssp_bos_known(dst) ? \ __builtin___memmove_chk(dst, src, len, __ssp_bos0(dst)) : \ __memmove_ichk(dst, src, len)) #define bzero(dst, len) \ - ((__ssp_bos0(dst) != (size_t)-1) ? \ + (__ssp_bos_known(dst) ? \ __builtin___memset_chk(dst, 0, len, __ssp_bos0(dst)) : \ __memset_ichk(dst, 0, len)) #endif diff --git a/newlib/libc/include/sys/features.h b/newlib/libc/include/sys/features.h index a7d4bc52d18f..6a925c87e9ec 100644 --- a/newlib/libc/include/sys/features.h +++ b/newlib/libc/include/sys/features.h @@ -104,7 +104,7 @@ extern "C" { * _DEFAULT_SOURCE (or none of the above) * POSIX-1.2008 with BSD and SVr4 extensions * - * _FORTIFY_SOURCE = 1 or 2 + * _FORTIFY_SOURCE = 1, 2 or 3 * Object Size Checking function wrappers */ @@ -247,7 +247,7 @@ extern "C" { * GNU extensions; enabled with _GNU_SOURCE. * * __SSP_FORTIFY_LEVEL - * Object Size Checking; defined to 0 (off), 1, or 2. + * Object Size Checking; defined to 0 (off), 1, 2 or 3. * * In all cases above, "enabled by default" means either by defining * _DEFAULT_SOURCE, or by not defining any of the public feature test macros. @@ -335,7 +335,13 @@ extern "C" { #if _FORTIFY_SOURCE > 0 && !defined(__cplusplus) && !defined(__lint__) && \ (__OPTIMIZE__ > 0 || defined(__clang__)) && __GNUC_PREREQ__(4, 1) && \ !defined(_LIBC) -# if _FORTIFY_SOURCE > 1 +# if _FORTIFY_SOURCE > 2 && defined(__has_builtin) +# if __has_builtin(__builtin_dynamic_object_size) +# define __SSP_FORTIFY_LEVEL 3 +# else +# define __SSP_FORTIFY_LEVEL 2 +# endif +# elif _FORTIFY_SOURCE > 1 # define __SSP_FORTIFY_LEVEL 2 # else # define __SSP_FORTIFY_LEVEL 1
reply other threads:[~2024-01-29 15:29 UTC|newest] Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20240129152901.47F4F385840B@sourceware.org \ --to=corinna@sourceware.org \ --cc=newlib-cvs@sourceware.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).