From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- arch/powerpc/boot/hack-coff.c | 80 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 arch/powerpc/boot/hack-coff.c (limited to 'arch/powerpc/boot/hack-coff.c') diff --git a/arch/powerpc/boot/hack-coff.c b/arch/powerpc/boot/hack-coff.c new file mode 100644 index 000000000..6bf0c9430 --- /dev/null +++ b/arch/powerpc/boot/hack-coff.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * hack-coff.c - hack the header of an xcoff file to fill in + * a few fields needed by the Open Firmware xcoff loader on + * Power Macs but not initialized by objcopy. + * + * Copyright (C) Paul Mackerras 1997. + */ +#include +#include +#include +#include +#include +#include "rs6000.h" + +#define AOUT_MAGIC 0x010b + +#define get_16be(x) ((((unsigned char *)(x))[0] << 8) \ + + ((unsigned char *)(x))[1]) +#define put_16be(x, v) (((unsigned char *)(x))[0] = (v) >> 8, \ + ((unsigned char *)(x))[1] = (v) & 0xff) +#define get_32be(x) ((((unsigned char *)(x))[0] << 24) \ + + (((unsigned char *)(x))[1] << 16) \ + + (((unsigned char *)(x))[2] << 8) \ + + ((unsigned char *)(x))[3]) + +int +main(int ac, char **av) +{ + int fd; + int i, nsect; + int aoutsz; + struct external_filehdr fhdr; + struct aouthdr aout; + struct external_scnhdr shdr; + + if (ac != 2) { + fprintf(stderr, "Usage: hack-coff coff-file\n"); + exit(1); + } + if ((fd = open(av[1], 2)) == -1) { + perror(av[2]); + exit(1); + } + if (read(fd, &fhdr, sizeof(fhdr)) != sizeof(fhdr)) + goto readerr; + i = get_16be(fhdr.f_magic); + if (i != U802TOCMAGIC && i != U802WRMAGIC && i != U802ROMAGIC) { + fprintf(stderr, "%s: not an xcoff file\n", av[1]); + exit(1); + } + aoutsz = get_16be(fhdr.f_opthdr); + if (read(fd, &aout, aoutsz) != aoutsz) + goto readerr; + nsect = get_16be(fhdr.f_nscns); + for (i = 0; i < nsect; ++i) { + if (read(fd, &shdr, sizeof(shdr)) != sizeof(shdr)) + goto readerr; + if (strcmp(shdr.s_name, ".text") == 0) { + put_16be(aout.o_snentry, i+1); + put_16be(aout.o_sntext, i+1); + } else if (strcmp(shdr.s_name, ".data") == 0) { + put_16be(aout.o_sndata, i+1); + } else if (strcmp(shdr.s_name, ".bss") == 0) { + put_16be(aout.o_snbss, i+1); + } + } + put_16be(aout.magic, AOUT_MAGIC); + if (lseek(fd, (long) sizeof(struct external_filehdr), 0) == -1 + || write(fd, &aout, aoutsz) != aoutsz) { + fprintf(stderr, "%s: write error\n", av[1]); + exit(1); + } + close(fd); + exit(0); + +readerr: + fprintf(stderr, "%s: read error or file too short\n", av[1]); + exit(1); +} -- cgit v1.3.1