From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1944) id C5E893851503; Thu, 27 Oct 2022 13:57:57 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org C5E893851503 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1666879077; bh=w0CTqAo78TUEwrFwWamN7rYZXPQjRSTN49G5kNpnnVY=; h=From:To:Subject:Date:From; b=x0Kg/u92U1BjZi0rjn4QCo8bQKYy+irRwFoV98m78wK3SSmrcVtJdXcwFAje9b992 dQYn5giDWkYY2PK1nmsYJ1nr7cPHsz1Z8LWe1sbheQq+AFapIIVnJm/NHArCsVlqgD sc2HZJib7kDQlqyK0kvgw1CtPKlIHL0WCj/MqcDc= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Szabolcs Nagy To: glibc-cvs@sourceware.org Subject: [glibc/arm/morello/main] cheri: elf: Fix segment mapping permissions X-Act-Checkin: glibc X-Git-Author: Szabolcs Nagy X-Git-Refname: refs/heads/arm/morello/main X-Git-Oldrev: 5eedf66625842a56c0ed7e16a1f79fda4b52b425 X-Git-Newrev: 28bd4285ad0f8ce6026583e9cc0a612018d461ba Message-Id: <20221027135757.C5E893851503@sourceware.org> Date: Thu, 27 Oct 2022 13:57:57 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=28bd4285ad0f8ce6026583e9cc0a612018d461ba commit 28bd4285ad0f8ce6026583e9cc0a612018d461ba Author: Szabolcs Nagy Date: Fri Oct 21 12:38:26 2022 +0100 cheri: elf: Fix segment mapping permissions Ensure mmap returns pointers with RWX permission covering all segments. These pointers later get restricted to RX and RW permission. Diff: --- elf/dl-map-segments.h | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/elf/dl-map-segments.h b/elf/dl-map-segments.h index ce51585ce4..e25fb579df 100644 --- a/elf/dl-map-segments.h +++ b/elf/dl-map-segments.h @@ -22,6 +22,13 @@ # include #endif +/* Allow RWX mprotect later, on CHERI this means RWX capability permission. */ +#ifdef PROT_MAX +# define PROT_MAX_RWX PROT_MAX (PROT_READ | PROT_WRITE | PROT_EXEC) +#else +# define PROT_MAX_RWX 0 +#endif + /* Map a segment and align it properly. */ static __always_inline elfptr_t @@ -29,7 +36,8 @@ _dl_map_segment (const struct loadcmd *c, ElfW(Addr) mappref, const size_t maplength, int fd) { if (__glibc_likely (c->mapalign <= GLRO(dl_pagesize))) - return (elfptr_t) __mmap ((void *) mappref, maplength, c->prot, + return (elfptr_t) __mmap ((void *) mappref, maplength, + c->prot|PROT_MAX_RWX, MAP_COPY|MAP_FILE, fd, c->mapoff); /* If the segment alignment > the page size, allocate enough space to @@ -38,7 +46,7 @@ _dl_map_segment (const struct loadcmd *c, ElfW(Addr) mappref, ? (maplength + c->mapalign) : (2 * c->mapalign)); elfptr_t map_start = (elfptr_t) __mmap ((void *) mappref, maplen, - PROT_NONE, + PROT_NONE|PROT_MAX_RWX, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); if (__glibc_unlikely ((void *) map_start == MAP_FAILED)) @@ -46,7 +54,7 @@ _dl_map_segment (const struct loadcmd *c, ElfW(Addr) mappref, elfptr_t map_start_aligned = ALIGN_UP (map_start, c->mapalign); map_start_aligned = (elfptr_t) __mmap ((void *) map_start_aligned, - maplength, c->prot, + maplength, c->prot|PROT_MAX_RWX, MAP_COPY|MAP_FILE|MAP_FIXED, fd, c->mapoff); if (__glibc_unlikely ((void *) map_start_aligned == MAP_FAILED)) @@ -137,7 +145,8 @@ _dl_map_segments (struct link_map *l, int fd, else { /* Need a single capability to cover all load segments. */ - void *p = __mmap ((void *) c->mapstart, maplength, c->prot, + void *p = __mmap ((void *) c->mapstart, maplength, + c->prot|PROT_MAX_RWX, MAP_FIXED|MAP_COPY|MAP_FILE, fd, c->mapoff); if (p == MAP_FAILED)