From: Heiko Stuebner <heiko@sntech.de>
To: linux-riscv@lists.infradead.org, palmer@dabbelt.com
Cc: christoph.muellner@vrull.eu, prabhakar.csengg@gmail.com,
conor@kernel.org, philipp.tomsich@vrull.eu,
ajones@ventanamicro.com, heiko@sntech.de,
emil.renner.berthing@canonical.com,
Heiko Stuebner <heiko.stuebner@vrull.eu>
Subject: [PATCH 5/7] RISC-V: fix auipc-jalr addresses in patched alternatives
Date: Thu, 10 Nov 2022 17:49:22 +0100 [thread overview]
Message-ID: <20221110164924.529386-6-heiko@sntech.de> (raw)
In-Reply-To: <20221110164924.529386-1-heiko@sntech.de>
From: Heiko Stuebner <heiko.stuebner@vrull.eu>
Alternatives live in a different section, so addresses used by call
functions will point to wrong locations after the patch got applied.
Similar to arm64, adjust the location to consider that offset.
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
---
arch/riscv/kernel/cpufeature.c | 79 +++++++++++++++++++++++++++++++++-
1 file changed, 77 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 694267d1fe81..026512ca9c4c 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -298,6 +298,74 @@ static u32 __init_or_module cpufeature_probe(unsigned int stage)
return cpu_req_feature;
}
+#include <asm/parse_asm.h>
+
+DECLARE_INSN(jalr, MATCH_JALR, MASK_JALR)
+DECLARE_INSN(auipc, MATCH_AUIPC, MASK_AUIPC)
+
+static inline bool is_auipc_jalr_pair(long insn1, long insn2)
+{
+ return is_auipc_insn(insn1) && is_jalr_insn(insn2);
+}
+
+#define JALR_SIGN_MASK BIT(I_IMM_SIGN_OPOFF - I_IMM_11_0_OPOFF)
+#define JALR_OFFSET_MASK I_IMM_11_0_MASK
+#define AUIPC_OFFSET_MASK U_IMM_31_12_MASK
+#define AUIPC_PAD (0x00001000)
+#define JALR_SHIFT I_IMM_11_0_OPOFF
+
+#define to_jalr_imm(offset) \
+ ((offset & I_IMM_11_0_MASK) << I_IMM_11_0_OPOFF)
+
+#define to_auipc_imm(offset) \
+ ((offset & JALR_SIGN_MASK) ? \
+ ((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) : \
+ (offset & AUIPC_OFFSET_MASK))
+
+static void riscv_alternative_fix_auipc_jalr(unsigned int *alt_ptr,
+ unsigned int len, int patch_offset)
+{
+ int num_instr = len / sizeof(u32);
+ unsigned int call[2];
+ int i;
+ int imm1;
+ u32 rd1;
+
+ for (i = 0; i < num_instr; i++) {
+ /* is there a further instruction? */
+ if (i + 1 >= num_instr)
+ continue;
+
+ if (!is_auipc_jalr_pair(*(alt_ptr + i), *(alt_ptr + i + 1)))
+ continue;
+
+ /* call will use ra register */
+ rd1 = EXTRACT_RD_REG(*(alt_ptr + i));
+ if (rd1 != 1)
+ continue;
+
+ /* get and adjust new target address */
+ imm1 = EXTRACT_UTYPE_IMM(*(alt_ptr + i));
+ imm1 += EXTRACT_ITYPE_IMM(*(alt_ptr + i + 1));
+ imm1 -= patch_offset;
+
+ /* pick the original auipc + jalr */
+ call[0] = *(alt_ptr + i);
+ call[1] = *(alt_ptr + i + 1);
+
+ /* drop the old IMMs */
+ call[0] &= ~(U_IMM_31_12_MASK);
+ call[1] &= ~(I_IMM_11_0_MASK << I_IMM_11_0_OPOFF);
+
+ /* add the adapted IMMs */
+ call[0] |= to_auipc_imm(imm1);
+ call[1] |= to_jalr_imm(imm1);
+
+ /* patch the call place again */
+ patch_text_nosync(alt_ptr + i * sizeof(u32), call, 8);
+ }
+}
+
void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin,
struct alt_entry *end,
unsigned int stage)
@@ -316,8 +384,15 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin,
}
tmp = (1U << alt->errata_id);
- if (cpu_req_feature & tmp)
- patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len);
+ if (cpu_req_feature & tmp) {
+ /* do the basic patching */
+ patch_text_nosync(alt->old_ptr, alt->alt_ptr,
+ alt->alt_len);
+
+ riscv_alternative_fix_auipc_jalr(alt->old_ptr,
+ alt->alt_len,
+ alt->old_ptr - alt->alt_ptr);
+ }
}
}
#endif
--
2.35.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2022-11-10 16:50 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-10 16:49 [PATCH 0/7] Zbb string optimizations and call support in alternatives Heiko Stuebner
2022-11-10 16:49 ` [PATCH 1/7] efi/riscv: libstub: mark when compiling libstub Heiko Stuebner
2022-11-13 17:16 ` Conor Dooley
2022-11-13 17:20 ` Heiko Stübner
2022-11-13 18:06 ` Conor Dooley
2022-11-10 16:49 ` [PATCH 2/7] RISC-V: add auipc elements to parse_asm header Heiko Stuebner
2022-11-13 17:18 ` Conor Dooley
2022-11-10 16:49 ` [PATCH 3/7] RISC-V: add U-type imm parsing " Heiko Stuebner
2022-11-13 19:06 ` Conor Dooley
2022-11-10 16:49 ` [PATCH 4/7] RISC-V: add rd reg " Heiko Stuebner
2022-11-13 19:08 ` Conor Dooley
2022-11-10 16:49 ` Heiko Stuebner [this message]
2022-11-13 20:31 ` [PATCH 5/7] RISC-V: fix auipc-jalr addresses in patched alternatives Conor Dooley
2022-11-14 10:57 ` Emil Renner Berthing
2022-11-14 11:35 ` Andrew Jones
2022-11-14 11:38 ` Emil Renner Berthing
2022-11-14 11:38 ` Heiko Stübner
2022-11-14 12:15 ` Andrew Jones
2022-11-14 12:29 ` Emil Renner Berthing
2022-11-14 12:47 ` Philipp Tomsich
2022-11-15 14:28 ` Lad, Prabhakar
2022-11-17 11:51 ` Heiko Stübner
2022-11-21 9:50 ` Lad, Prabhakar
2022-11-21 11:27 ` Heiko Stübner
2022-11-21 15:06 ` Lad, Prabhakar
2022-11-21 21:31 ` Lad, Prabhakar
2022-11-21 22:17 ` Heiko Stübner
2022-11-21 22:38 ` Heiko Stübner
2022-11-22 0:16 ` Lad, Prabhakar
2022-11-21 23:59 ` Lad, Prabhakar
2022-11-22 10:59 ` Lad, Prabhakar
2022-11-22 11:19 ` Heiko Stübner
2022-11-22 11:37 ` Heiko Stübner
2022-11-22 12:28 ` Lad, Prabhakar
2022-11-10 16:49 ` [PATCH 6/7] RISC-V: add infrastructure to allow different str* implementations Heiko Stuebner
2022-11-13 22:07 ` Conor Dooley
2022-11-10 16:49 ` [PATCH 7/7] RISC-V: add zbb support to string functions Heiko Stuebner
2022-11-13 23:29 ` Conor Dooley
2022-11-13 23:47 ` Heiko Stübner
2022-11-24 22:23 ` Heiko Stübner
2022-11-24 22:32 ` Conor Dooley
2022-11-24 23:51 ` Heiko Stuebner
2022-11-25 7:49 ` Andrew Jones
2022-11-25 8:17 ` Conor.Dooley
[not found] ` <CAEg0e7h9skbWPVDsz9CdB8dATN5XM9eT-uPY0A7xRZmX=qTU6A@mail.gmail.com>
2022-11-25 15:28 ` Andrew Jones
2022-11-25 16:35 ` Christoph Müllner
2022-11-25 16:39 ` Conor Dooley
2022-11-25 17:02 ` Christoph Müllner
2022-11-25 17:11 ` Conor Dooley
2022-11-25 17:42 ` Christoph Müllner
2022-11-25 16:36 ` Conor Dooley
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=20221110164924.529386-6-heiko@sntech.de \
--to=heiko@sntech.de \
--cc=ajones@ventanamicro.com \
--cc=christoph.muellner@vrull.eu \
--cc=conor@kernel.org \
--cc=emil.renner.berthing@canonical.com \
--cc=heiko.stuebner@vrull.eu \
--cc=linux-riscv@lists.infradead.org \
--cc=palmer@dabbelt.com \
--cc=philipp.tomsich@vrull.eu \
--cc=prabhakar.csengg@gmail.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 NNTP newsgroup(s).