unofficial mirror of libc-alpha@sourceware.org
 help / color / mirror / Atom feed
From: Vineet Gupta <vineetg@rivosinc.com>
To: Vincent Chen <vincent.chen@sifive.com>
Cc: "Florian Weimer" <fweimer@redhat.com>,
	"Rich Felker" <dalias@libc.org>,
	"Andrew Waterman" <andrew@sifive.com>,
	"Palmer Dabbelt" <palmer@rivosinc.com>,
	"Kito Cheng" <kito.cheng@sifive.com>,
	"Christoph Müllner" <christoph.muellner@vrull.eu>,
	davidlt@rivosinc.com, "Arnd Bergmann" <arnd@arndb.de>,
	"Björn Töpel" <bjorn@kernel.org>,
	"Philipp Tomsich" <philipp.tomsich@vrull.eu>,
	"Szabolcs Nagy" <szabolcs.nagy@arm.com>,
	"Andy Chiu" <andy.chiu@sifive.com>,
	"Greentime Hu" <greentime.hu@sifive.com>,
	"Aaron Durbin" <adurbin@rivosinc.com>,
	"Andrew de los Reyes" <adlr@rivosinc.com>,
	linux-riscv <linux-riscv@lists.infradead.org>,
	"GNU C Library" <libc-alpha@sourceware.org>
Subject: Re: Adding V-ext regs to signal context w/o expanding kernel struct sigcontext to avoid glibc ABI break
Date: Wed, 21 Dec 2022 11:52:04 -0800	[thread overview]
Message-ID: <7430f494-9b43-5e03-c1e9-6b83e2611a11@rivosinc.com> (raw)
In-Reply-To: <50c598a6-e3b3-3062-abe7-23a406067533@rivosinc.com>



On 12/21/22 11:45, Vineet Gupta wrote:
>
> 4. Kernel with RVV support + user program using original Glibc sigcontext
> In this case, the kernel needs to save vector registers context to
> memory. The user program may encounter memory issues if the user space
> does not reserve enough memory size for the kernel to create the
> sigcontext. However, we can't seem to avoid this case since there is
> no flexible memory area in struct sigcontext for future expansion.

This is not an issue, if we don't change sigcontext (in kernel and 
glibc) - it is essentially the case of existing binaries.
kernel still saves regs on user stack, in rt_sigframe, its just that  
userspace is not able to access them in SA_SIGINFO signal handers.
aarch64 have this implemented this approach and it is likely they can't 
do that either for SVE regs.

  reply	other threads:[~2022-12-21 19:52 UTC|newest]

Thread overview: 79+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-13  1:41 [RFC patch 0/5] RISC-V: Add vector ISA support Vincent Chen
2021-09-13  1:41 ` [RFC patch 1/5] RISC-V: Remove riscv-specific sigcontext.h Vincent Chen
2021-09-13  1:41 ` [RFC patch 2/5] RISC-V: Reserve about 5K space in mcontext_t to support future ISA expansion Vincent Chen
2021-09-13 13:44   ` Florian Weimer via Libc-alpha
2021-09-13 13:52     ` Rich Felker
2021-09-16  8:02       ` Vincent Chen
2021-09-16  8:14         ` Florian Weimer via Libc-alpha
2021-09-18  3:04           ` Vincent Chen
2022-12-09  3:39             ` RISCV kernel struct sigcontext expansion for V regs and potential glibc ABI break (was Re: [RFC patch 2/5] RISC-V: Reserve about 5K space in mcontext_t to support future ISA expansion.) Vineet Gupta
2022-12-09  4:03               ` Vineet Gupta
2022-12-20 20:05               ` Adding V-ext regs to signal context w/o expanding kernel struct sigcontext to avoid glibc ABI break Vineet Gupta
2022-12-21 15:53                 ` Vincent Chen
2022-12-21 19:45                   ` Vineet Gupta
2022-12-21 19:52                     ` Vineet Gupta [this message]
2022-12-22  3:37                       ` Vincent Chen
2022-12-22 19:25                         ` Vineet Gupta
2022-12-23  2:27                           ` Vincent Chen
2022-12-23 19:42                             ` Vineet Gupta
2022-12-22  5:32                       ` Richard Henderson via Libc-alpha
2022-12-22 18:33                         ` Andy Chiu
2022-12-22 20:27                           ` Vineet Gupta
2022-12-28 10:53                             ` Andy Chiu
2023-01-03 19:17                               ` Vineet Gupta
2023-01-04 16:34                                 ` Andy Chiu
2023-01-04 20:46                                   ` Vineet Gupta
2023-01-04 21:29                                     ` Philipp Tomsich
2023-01-04 21:37                                       ` Andrew Waterman
2023-01-04 22:43                                       ` Vineet Gupta
2023-01-09 13:33                                         ` Kito Cheng
2023-01-09 19:16                                           ` Vineet Gupta
2023-01-10 13:21                                             ` Kito Cheng
2023-01-10 18:07                                               ` Auto-enabling V unit and/or use of elf attributes (was Re: Adding V-ext regs to signal context w/o expanding kernel struct sigcontext to avoid glibc ABI break) Vineet Gupta
2023-01-11  1:22                                                 ` Richard Henderson via Libc-alpha
2023-01-11  4:28                                                   ` Jeff Law
2023-01-11  4:57                                                     ` Richard Henderson via Libc-alpha
2023-01-11  5:07                                                       ` Jeff Law
2023-01-11  6:00                                                         ` Andy Chiu
2023-01-11  6:20                                                           ` Jeff Law
2023-01-11  9:28                                                             ` Andy Chiu
2023-01-11 12:13                                                               ` Andy Chiu
2023-01-23 12:17                                                                 ` Conor Dooley via Libc-alpha
2023-01-23 13:29                                                                   ` Andy Chiu
2023-01-11  5:05                                                   ` Anup Patel
2023-01-11  5:23                                                   ` Richard Henderson via Libc-alpha
2022-12-22 22:33                           ` Adding V-ext regs to signal context w/o expanding kernel struct sigcontext to avoid glibc ABI break Richard Henderson via Libc-alpha
2022-12-22 23:47                           ` Conor Dooley via Libc-alpha
2022-12-22 23:58                             ` Vineet Gupta
2022-12-22 20:30                         ` Vineet Gupta
2022-12-22 21:38                           ` Andrew Waterman
2022-12-22  1:50                     ` Vincent Chen
2022-12-22  5:34                     ` Richard Henderson via Libc-alpha
2021-09-16 23:56         ` [RFC patch 2/5] RISC-V: Reserve about 5K space in mcontext_t to support future ISA expansion Ben Woodard via Libc-alpha
2021-09-18  3:15           ` Vincent Chen
2021-09-20 16:41             ` DJ Delorie via Libc-alpha
2021-09-20 17:10               ` Florian Weimer via Libc-alpha
2021-10-01  1:43                 ` Vincent Chen
2021-10-01 12:08                   ` Adhemerval Zanella via Libc-alpha
2021-09-17 17:03         ` Rich Felker
2021-09-18  3:19           ` Vincent Chen
2021-09-13  1:41 ` [RFC patch 3/5] RISC-V: Save and restore VCSR when doing user context switch Vincent Chen
2021-09-14 23:48   ` Joseph Myers
2021-09-15  0:13     ` Andrew Waterman
2021-09-16  9:20       ` Vincent Chen
2021-10-01 13:04   ` Adhemerval Zanella via Libc-alpha
2021-09-13  1:41 ` [RFC patch 4/5] RISC-V: Extend MINSIGSTKSZ and SIGSTKSZ to backup RVV registers Vincent Chen
2021-09-13 13:51   ` Rich Felker
2021-09-16  9:25     ` Vincent Chen
2021-09-13  1:41 ` [RFC 5/5] RISC-V: Expand PTHREAD_STACK_MIN to support RVV environment Vincent Chen
2021-09-14 23:43   ` Joseph Myers
2021-09-15 10:42     ` Florian Weimer via Libc-alpha
2021-09-15 14:31       ` H.J. Lu via Libc-alpha
2021-09-16 10:21         ` Vincent Chen
2021-09-13 19:11 ` [RFC patch 0/5] RISC-V: Add vector ISA support Vineet Gupta via Libc-alpha
2021-09-15 19:37   ` Jim Wilson
2021-11-09 19:21 ` Darius Rad
2021-11-09 19:30   ` Andrew Waterman
2021-11-09 22:03     ` Darius Rad
2021-11-09 22:18       ` Andrew Waterman
2021-11-10 11:39         ` Darius Rad

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

  List information: https://www.gnu.org/software/libc/involved.html

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=7430f494-9b43-5e03-c1e9-6b83e2611a11@rivosinc.com \
    --to=vineetg@rivosinc.com \
    --cc=adlr@rivosinc.com \
    --cc=adurbin@rivosinc.com \
    --cc=andrew@sifive.com \
    --cc=andy.chiu@sifive.com \
    --cc=arnd@arndb.de \
    --cc=bjorn@kernel.org \
    --cc=christoph.muellner@vrull.eu \
    --cc=dalias@libc.org \
    --cc=davidlt@rivosinc.com \
    --cc=fweimer@redhat.com \
    --cc=greentime.hu@sifive.com \
    --cc=kito.cheng@sifive.com \
    --cc=libc-alpha@sourceware.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=palmer@rivosinc.com \
    --cc=philipp.tomsich@vrull.eu \
    --cc=szabolcs.nagy@arm.com \
    --cc=vincent.chen@sifive.com \
    /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: link
Be 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).