From: Richard Henderson <richard.henderson@linaro.org>
To: Warner Losh <imp@bsdimp.com>, qemu-devel@nongnu.org
Cc: kevans@freebsd.org, f4bug@amsat.org
Subject: Re: [PATCH v2 8/9] bsd-user/mmap.c: Implement MAP_EXCL, required by jemalloc in head
Date: Thu, 23 Sep 2021 10:52:50 -0700 [thread overview]
Message-ID: <4d7f5ce6-22c4-e9de-39c6-fb92d7096385@linaro.org> (raw)
In-Reply-To: <20210922045636.25206-9-imp@bsdimp.com>
On 9/21/21 9:56 PM, Warner Losh wrote:
> + /* Reject the mapping if any page within the range is mapped */
> + if (flags & MAP_EXCL) {
> + for (addr = start; addr < end; addr++) {
> + if (page_get_flags(addr) != 0)
> + goto fail;
> + }
> + }
How about
if ((flags & MAP_EXCL) &&
page_check_range(start, len, 0) < 0) {
goto fail;
}
Hmm. This (and your page_get_flags check) could assert due to out-of-range guest address.
You're currently attempting that,
/*
* Test if requested memory area fits target address space
* It can fail only on 64-bit host with 32-bit target.
* On any other target/host host mmap() handles this error correctly.
*/
#if TARGET_ABI_BITS == 32 && HOST_LONG_BITS == 64
if ((unsigned long)start + len - 1 > (abi_ulong) -1) {
errno = EINVAL;
goto fail;
}
#endif
but the test isn't correct. Note that reserved_va may be applied to 64-bit guests, and
certainly may be smaller than (abi_ulong)-1.
You want guest_range_valid_untagged here.
r~
next prev parent reply other threads:[~2021-09-24 12:09 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-22 4:56 [PATCH v2 0/9] bsd-user mmap fixes Warner Losh
2021-09-22 4:56 ` [PATCH v2 1/9] bsd-user/mmap.c: Always zero MAP_ANONYMOUS memory in mmap_frag() Warner Losh
2021-09-23 17:35 ` Richard Henderson
2021-09-22 4:56 ` [PATCH v2 2/9] bsd-user/mmap.c: check pread's return value to fix warnings with _FORTIFY_SOURCE Warner Losh
2021-09-23 17:36 ` Richard Henderson
2021-09-24 15:07 ` Warner Losh
2021-09-25 10:54 ` Philippe Mathieu-Daudé
2021-09-22 4:56 ` [PATCH v2 3/9] bsd-user/mmap.c: MAP_ symbols are defined, so no need for ifdefs Warner Losh
2021-09-23 17:37 ` Richard Henderson
2021-09-22 4:56 ` [PATCH v2 4/9] bsd-user/mmap.c: mmap return ENOMEM on overflow Warner Losh
2021-09-23 17:38 ` Richard Henderson
2021-09-25 10:55 ` Philippe Mathieu-Daudé
2021-09-22 4:56 ` [PATCH v2 5/9] bsd-user/mmap.c: mmap prefer MAP_ANON for BSD Warner Losh
2021-09-23 17:38 ` Richard Henderson
2021-09-22 4:56 ` [PATCH v2 6/9] bsd-user/mmap.c: line wrap change Warner Losh
2021-09-23 17:41 ` Richard Henderson
2021-09-26 16:46 ` Warner Losh
2021-09-22 4:56 ` [PATCH v2 7/9] bsd-user/mmap.c: Don't mmap fd == -1 independently from MAP_ANON flag Warner Losh
2021-09-23 17:43 ` Richard Henderson
2021-09-26 17:08 ` Warner Losh
2021-09-26 19:07 ` Guy Yur
2021-09-27 0:17 ` Warner Losh
2021-09-22 4:56 ` [PATCH v2 8/9] bsd-user/mmap.c: Implement MAP_EXCL, required by jemalloc in head Warner Losh
2021-09-23 17:52 ` Richard Henderson [this message]
2021-09-26 18:38 ` Warner Losh
2021-09-22 4:56 ` [PATCH v2 9/9] bsd-user/mmap.c: assert that target_mprotect cannot fail Warner Losh
2021-09-23 17:53 ` Richard Henderson
2021-09-25 10:58 ` Philippe Mathieu-Daudé
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