From df0f9a664be55a8529362a1ada847a19a91e4807 Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Thu, 16 Oct 2025 13:51:23 -0700 Subject: [PATCH] parisc: Inline a type punning version of get_unaligned_le32() Reading the byte/char output_len with get_unaligned_le32() can trigger compiler warnings due to the size read. Avoid these warnings by using type punning. This avoids issues when switching get_unaligned_t() to __builtin_memcpy(). Signed-off-by: Ian Rogers Signed-off-by: Thomas Gleixner Link: https://patch.msgid.link/20251016205126.2882625-2-irogers@google.com --- arch/parisc/boot/compressed/misc.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/arch/parisc/boot/compressed/misc.c b/arch/parisc/boot/compressed/misc.c index 9c83bd06ef154..111f267230a19 100644 --- a/arch/parisc/boot/compressed/misc.c +++ b/arch/parisc/boot/compressed/misc.c @@ -278,6 +278,19 @@ static void parse_elf(void *output) free(phdrs); } +/* + * The regular get_unaligned_le32 uses __builtin_memcpy which can trigger + * warnings when reading a byte/char output_len as an integer, as the size of a + * char is less than that of an integer. Use type punning and the packed + * attribute, which requires -fno-strict-aliasing, to work around the problem. + */ +static u32 punned_get_unaligned_le32(const void *p) +{ + const struct { __le32 x; } __packed * __get_pptr = p; + + return le32_to_cpu(__get_pptr->x); +} + asmlinkage unsigned long __visible decompress_kernel(unsigned int started_wide, unsigned int command_line, const unsigned int rd_start, @@ -309,7 +322,7 @@ asmlinkage unsigned long __visible decompress_kernel(unsigned int started_wide, * leave 2 MB for the stack. */ vmlinux_addr = (unsigned long) &_ebss + 2*1024*1024; - vmlinux_len = get_unaligned_le32(&output_len); + vmlinux_len = punned_get_unaligned_le32(&output_len); output = (char *) vmlinux_addr; /* -- 2.47.3