Messages in this thread Patch in this message | | | Date | Wed, 8 Nov 2023 19:44:48 +0200 | From | Lasse Collin <> | Subject | [PATCH] lib/xz: Add ARM64 BCJ filter |
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From: Lasse Collin <lasse.collin@tukaani.org>
ARM64 kernel decompression is done by bootloaders but the filter can still be useful, for example, for Squashfs.
A duplicated check for XZ_DEC_ARM in xz_private.h was omitted too.
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org> ---
lib/xz/Kconfig | 5 +++++ lib/xz/xz_dec_bcj.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++- lib/xz/xz_private.h | 7 +++++-- 3 files changed, 59 insertions(+), 3 deletions(-)
diff -rup linux-6.6.orig/lib/xz/Kconfig linux-6.6/lib/xz/Kconfig --- linux-6.6.orig/lib/xz/Kconfig 2023-10-30 04:31:08.000000000 +0200 +++ linux-6.6/lib/xz/Kconfig 2023-11-08 16:27:17.661462876 +0200 @@ -34,6 +34,11 @@ config XZ_DEC_ARMTHUMB default y select XZ_DEC_BCJ +config XZ_DEC_ARM64 + bool "ARM64 BCJ filter decoder" if EXPERT + default y + select XZ_DEC_BCJ + config XZ_DEC_SPARC bool "SPARC BCJ filter decoder" if EXPERT default y diff -rup linux-6.6.orig/lib/xz/xz_dec_bcj.c linux-6.6/lib/xz/xz_dec_bcj.c --- linux-6.6.orig/lib/xz/xz_dec_bcj.c 2023-10-30 04:31:08.000000000 +0200 +++ linux-6.6/lib/xz/xz_dec_bcj.c 2023-11-08 16:29:37.949475877 +0200 @@ -24,7 +24,8 @@ struct xz_dec_bcj { BCJ_IA64 = 6, /* Big or little endian */ BCJ_ARM = 7, /* Little endian only */ BCJ_ARMTHUMB = 8, /* Little endian only */ - BCJ_SPARC = 9 /* Big or little endian */ + BCJ_SPARC = 9, /* Big or little endian */ + BCJ_ARM64 = 10 /* AArch64 */ } type; /* @@ -334,6 +335,45 @@ static size_t bcj_sparc(struct xz_dec_bc } #endif +#ifdef XZ_DEC_ARM64 +static size_t bcj_arm64(struct xz_dec_bcj *s, uint8_t *buf, size_t size) +{ + size_t i; + uint32_t instr; + uint32_t addr; + + for (i = 0; i + 4 <= size; i += 4) { + instr = get_unaligned_le32(buf + i); + + if ((instr >> 26) == 0x25) { + /* BL instruction */ + addr = instr - ((s->pos + (uint32_t)i) >> 2); + instr = 0x94000000 | (addr & 0x03FFFFFF); + put_unaligned_le32(instr, buf + i); + + } else if ((instr & 0x9F000000) == 0x90000000) { + /* ADRP instruction */ + addr = ((instr >> 29) & 3) | ((instr >> 3) & 0x1FFFFC); + + /* Only convert values in the range +/-512 MiB. */ + if ((addr + 0x020000) & 0x1C0000) + continue; + + addr -= (s->pos + (uint32_t)i) >> 12; + + instr &= 0x9000001F; + instr |= (addr & 3) << 29; + instr |= (addr & 0x03FFFC) << 3; + instr |= (0U - (addr & 0x020000)) & 0xE00000; + + put_unaligned_le32(instr, buf + i); + } + } + + return i; +} +#endif + /* * Apply the selected BCJ filter. Update *pos and s->pos to match the amount * of data that got filtered. @@ -381,6 +421,11 @@ static void bcj_apply(struct xz_dec_bcj filtered = bcj_sparc(s, buf, size); break; #endif +#ifdef XZ_DEC_ARM64 + case BCJ_ARM64: + filtered = bcj_arm64(s, buf, size); + break; +#endif default: /* Never reached but silence compiler warnings. */ filtered = 0; @@ -554,6 +599,9 @@ XZ_EXTERN enum xz_ret xz_dec_bcj_reset(s #ifdef XZ_DEC_SPARC case BCJ_SPARC: #endif +#ifdef XZ_DEC_ARM64 + case BCJ_ARM64: +#endif break; default: diff -rup linux-6.6.orig/lib/xz/xz_private.h linux-6.6/lib/xz/xz_private.h --- linux-6.6.orig/lib/xz/xz_private.h 2023-10-30 04:31:08.000000000 +0200 +++ linux-6.6/lib/xz/xz_private.h 2023-11-08 16:31:17.155717209 +0200 @@ -37,6 +37,9 @@ # ifdef CONFIG_XZ_DEC_SPARC # define XZ_DEC_SPARC # endif +# ifdef CONFIG_XZ_DEC_ARM64 +# define XZ_DEC_ARM64 +# endif # ifdef CONFIG_XZ_DEC_MICROLZMA # define XZ_DEC_MICROLZMA # endif @@ -98,9 +101,9 @@ */ #ifndef XZ_DEC_BCJ # if defined(XZ_DEC_X86) || defined(XZ_DEC_POWERPC) \ - || defined(XZ_DEC_IA64) || defined(XZ_DEC_ARM) \ + || defined(XZ_DEC_IA64) \ || defined(XZ_DEC_ARM) || defined(XZ_DEC_ARMTHUMB) \ - || defined(XZ_DEC_SPARC) + || defined(XZ_DEC_SPARC) || defined(XZ_DEC_ARM64) # define XZ_DEC_BCJ # endif #endif
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