From: Richard Henderson <rth@twiddle.net>
To: Szabolcs Nagy <szabolcs.nagy@arm.com>, libc-alpha@sourceware.org
Cc: Sudakshina Das <sudi.das@arm.com>
Subject: Re: [PATCH v6 08/14] aarch64: enable BTI at runtime
Date: Sat, 11 Jul 2020 08:58:26 -0700 [thread overview]
Message-ID: <7e566a26-dc20-876f-d639-97e1fd2ab191@twiddle.net> (raw)
In-Reply-To: <f5a7a03e32f84ea6f5ba2cda5abcb50f40700bd3.1593612309.git.szabolcs.nagy@arm.com>
On 7/1/20 7:39 AM, Szabolcs Nagy wrote:
> + unsigned prot = PROT_READ | PROT_EXEC | PROT_BTI;
> +
> + for (phdr = map->l_phdr; phdr < &map->l_phdr[map->l_phnum]; ++phdr)
> + if (phdr->p_type == PT_LOAD && (phdr->p_flags & PF_X))
> + {
> + ElfW(Addr) start = phdr->p_vaddr + map->l_addr;
> + ElfW(Addr) len = phdr->p_memsz;
> + if (__mprotect ((void *) start, len, prot) < 0)
Spend an extra cycle or two and honor the exact set of p_flags?
If I construct an executable but non-readable PT_LOAD segment, that should be
fine. RWX with BTI would undoubtedly be an unusual case, but perhaps not
implausible in the context of a JIT with a statically allocated buffer.
r~
next prev parent reply other threads:[~2020-07-11 15:58 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-01 14:37 [PATCH v6 00/14] aarch64: branch protection support Szabolcs Nagy
2020-07-01 14:37 ` [PATCH v6 01/14] Rewrite abi-note.S in C Szabolcs Nagy
2020-07-01 14:41 ` H.J. Lu
2020-07-01 17:31 ` Szabolcs Nagy
2020-07-01 17:43 ` H.J. Lu
2020-07-02 8:39 ` Szabolcs Nagy
2020-07-01 14:38 ` [PATCH v6 02/14] aarch64: configure test for BTI support Szabolcs Nagy
2020-07-06 14:11 ` Adhemerval Zanella
2020-07-06 18:07 ` Szabolcs Nagy
2020-07-06 18:12 ` Adhemerval Zanella
2020-07-07 14:26 ` Szabolcs Nagy
2020-07-07 14:39 ` H.J. Lu
2020-07-07 16:58 ` Szabolcs Nagy
2020-07-07 17:24 ` H.J. Lu
2020-07-01 14:38 ` [PATCH v6 03/14] aarch64: Rename place holder .S files to .c Szabolcs Nagy
2020-07-01 14:38 ` [PATCH v6 04/14] aarch64: Add BTI support to assembly files Szabolcs Nagy
2020-07-03 16:19 ` Szabolcs Nagy
2020-07-01 14:38 ` [PATCH v6 05/14] aarch64: fix swapcontext for BTI Szabolcs Nagy
2020-07-01 14:39 ` [PATCH v6 06/14] aarch64: fix RTLD_START " Szabolcs Nagy
2020-07-01 14:39 ` [PATCH v6 07/14] rtld: Clean up PT_NOTE and add PT_GNU_PROPERTY handling Szabolcs Nagy
2020-07-06 16:11 ` Adhemerval Zanella
2020-07-01 14:39 ` [PATCH v6 08/14] aarch64: enable BTI at runtime Szabolcs Nagy
2020-07-06 17:28 ` Adhemerval Zanella
2020-07-11 15:58 ` Richard Henderson [this message]
2020-07-13 8:32 ` Szabolcs Nagy
2020-07-13 13:14 ` Szabolcs Nagy
2020-07-13 13:28 ` Szabolcs Nagy
2020-07-13 16:55 ` Richard Henderson
2020-07-01 14:39 ` [PATCH v6 09/14] aarch64: ensure objects are BTI compatible Szabolcs Nagy
2020-07-06 17:37 ` Adhemerval Zanella
2020-07-06 18:01 ` Szabolcs Nagy
2020-07-06 18:17 ` Adhemerval Zanella
2020-07-01 14:40 ` [PATCH v6 10/14] aarch64: configure check for pac-ret code generation Szabolcs Nagy
2020-07-01 14:40 ` [PATCH v6 11/14] aarch64: Add pac-ret support to assembly files Szabolcs Nagy
2020-07-01 14:40 ` [PATCH v6 12/14] aarch64: fix pac-ret support in _mcount Szabolcs Nagy
2020-07-06 18:33 ` Adhemerval Zanella
2020-07-01 14:40 ` [PATCH v6 13/14] aarch64: redefine RETURN_ADDRESS to strip PAC Szabolcs Nagy
2020-07-06 18:34 ` Adhemerval Zanella
2020-07-01 14:41 ` [PATCH v6 14/14] aarch64: add NEWS entry about branch protection support Szabolcs Nagy
2020-07-06 18:41 ` Adhemerval Zanella
2020-07-08 10:04 ` Szabolcs Nagy
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