From: Brian Gerst <brgerst@gmail.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org
Cc: Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
Thomas Gleixner <tglx@linutronix.de>,
"H . Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
Brian Gerst <brgerst@gmail.com>
Subject: [PATCH v2 4/6] x86-64: Remove inverse relocations
Date: Tue, 30 Nov 2021 15:55:47 -0500 [thread overview]
Message-ID: <20211130205549.116673-5-brgerst@gmail.com> (raw)
In-Reply-To: <20211130205549.116673-1-brgerst@gmail.com>
Now that the percpu section is not at a fixed address, inverse
relocations (which were needed to offset the effects of relocation on
RIP-relative percpu references) are no longer used.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/boot/compressed/misc.c | 14 +-------------
arch/x86/tools/relocs.c | 9 ---------
2 files changed, 1 insertion(+), 22 deletions(-)
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index a4339cb2d247..5d0ffab408cd 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -215,7 +215,7 @@ static void handle_relocations(void *output, unsigned long output_len,
/*
* Process relocations: 32 bit relocations first then 64 bit after.
- * Three sets of binary relocations are added to the end of the kernel
+ * Two sets of binary relocations are added to the end of the kernel
* before compression. Each relocation table entry is the kernel
* address of the location which needs to be updated stored as a
* 32-bit value which is sign extended to 64 bits.
@@ -225,8 +225,6 @@ static void handle_relocations(void *output, unsigned long output_len,
* kernel bits...
* 0 - zero terminator for 64 bit relocations
* 64 bit relocation repeated
- * 0 - zero terminator for inverse 32 bit relocations
- * 32 bit inverse relocation repeated
* 0 - zero terminator for 32 bit relocations
* 32 bit relocation repeated
*
@@ -243,16 +241,6 @@ static void handle_relocations(void *output, unsigned long output_len,
*(uint32_t *)ptr += delta;
}
#ifdef CONFIG_X86_64
- while (*--reloc) {
- long extended = *reloc;
- extended += map;
-
- ptr = (unsigned long)extended;
- if (ptr < min_addr || ptr > max_addr)
- error("inverse 32-bit relocation outside of kernel!\n");
-
- *(int32_t *)ptr -= delta;
- }
for (reloc--; *reloc; reloc--) {
long extended = *reloc;
extended += map;
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index b27980291ff8..e452b54ddaa1 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -28,7 +28,6 @@ struct relocs {
static struct relocs relocs16;
static struct relocs relocs32;
#if ELF_BITS == 64
-static struct relocs relocs32neg;
static struct relocs relocs64;
#define FMT PRIu64
#else
@@ -959,7 +958,6 @@ static void emit_relocs(int as_text, int use_real_mode)
/* Order the relocations for more efficient processing */
sort_relocs(&relocs32);
#if ELF_BITS == 64
- sort_relocs(&relocs32neg);
sort_relocs(&relocs64);
#else
sort_relocs(&relocs16);
@@ -991,13 +989,6 @@ static void emit_relocs(int as_text, int use_real_mode)
/* Now print each relocation */
for (i = 0; i < relocs64.count; i++)
write_reloc(relocs64.offset[i], stdout);
-
- /* Print a stop */
- write_reloc(0, stdout);
-
- /* Now print each inverse 32-bit relocation */
- for (i = 0; i < relocs32neg.count; i++)
- write_reloc(relocs32neg.offset[i], stdout);
#endif
/* Print a stop */
--
2.31.1
next prev parent reply other threads:[~2021-11-30 20:58 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-30 20:55 [PATCH v2 0/6] x86-64: Stack protector and percpu improvements Brian Gerst
2021-11-30 20:55 ` [PATCH v2 1/6] x86: Remove stack protector test scripts Brian Gerst
2021-11-30 20:55 ` [PATCH v2 2/6] x86-64: Convert stack protector to normal percpu variable Brian Gerst
2021-12-01 9:50 ` David Laight
2021-12-01 14:21 ` Brian Gerst
2021-12-02 22:51 ` Peter Zijlstra
2021-11-30 20:55 ` [PATCH v2 3/6] x86-64: Use relative per-cpu offsets Brian Gerst
2021-11-30 20:55 ` Brian Gerst [this message]
2021-11-30 20:55 ` [PATCH v2 5/6] kallsyms: Remove KALLSYMS_ABSOLUTE_PERCPU Brian Gerst
2021-11-30 20:55 ` [PATCH v2 6/6] percpu: Remove PER_CPU_FIRST_SECTION Brian Gerst
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=20211130205549.116673-5-brgerst@gmail.com \
--to=brgerst@gmail.com \
--cc=bp@alien8.de \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.