From 76e4fed847124690f7344a43d01dbcd7b2925353 Mon Sep 17 00:00:00 2001 From: Mykyta Yatsenko Date: Sun, 26 Oct 2025 20:38:46 +0000 Subject: lib: move freader into buildid.h Move struct freader and prototypes of the functions operating on it into the buildid.h. This allows reusing freader outside buildid, e.g. for file dynptr support added later. Signed-off-by: Mykyta Yatsenko Link: https://lore.kernel.org/r/20251026203853.135105-4-mykyta.yatsenko5@gmail.com Signed-off-by: Alexei Starovoitov --- lib/buildid.c | 29 +++++------------------------ 1 file changed, 5 insertions(+), 24 deletions(-) (limited to 'lib') diff --git a/lib/buildid.c b/lib/buildid.c index c4b0f376fb34..df06e492810d 100644 --- a/lib/buildid.c +++ b/lib/buildid.c @@ -11,27 +11,8 @@ #define MAX_PHDR_CNT 256 -struct freader { - void *buf; - u32 buf_sz; - int err; - union { - struct { - struct file *file; - struct folio *folio; - void *addr; - loff_t folio_off; - bool may_fault; - }; - struct { - const char *data; - u64 data_sz; - }; - }; -}; - -static void freader_init_from_file(struct freader *r, void *buf, u32 buf_sz, - struct file *file, bool may_fault) +void freader_init_from_file(struct freader *r, void *buf, u32 buf_sz, + struct file *file, bool may_fault) { memset(r, 0, sizeof(*r)); r->buf = buf; @@ -40,7 +21,7 @@ static void freader_init_from_file(struct freader *r, void *buf, u32 buf_sz, r->may_fault = may_fault; } -static void freader_init_from_mem(struct freader *r, const char *data, u64 data_sz) +void freader_init_from_mem(struct freader *r, const char *data, u64 data_sz) { memset(r, 0, sizeof(*r)); r->data = data; @@ -92,7 +73,7 @@ static int freader_get_folio(struct freader *r, loff_t file_off) return 0; } -static const void *freader_fetch(struct freader *r, loff_t file_off, size_t sz) +const void *freader_fetch(struct freader *r, loff_t file_off, size_t sz) { size_t folio_sz; @@ -147,7 +128,7 @@ static const void *freader_fetch(struct freader *r, loff_t file_off, size_t sz) return r->addr + (file_off - r->folio_off); } -static void freader_cleanup(struct freader *r) +void freader_cleanup(struct freader *r) { if (!r->buf) return; /* non-file-backed mode */ -- cgit v1.2.3 From 5a5fff604fa30a581197dca4204c35539fbedddb Mon Sep 17 00:00:00 2001 From: Mykyta Yatsenko Date: Sun, 26 Oct 2025 20:38:47 +0000 Subject: lib/freader: support reading more than 2 folios MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit freader_fetch currently reads from at most two folios. When a read spans into a third folio, the overflow bytes are copied adjacent to the second folio’s data instead of being handled as a separate folio. This patch modifies fetch algorithm to support reading from many folios. Signed-off-by: Mykyta Yatsenko Reviewed-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20251026203853.135105-5-mykyta.yatsenko5@gmail.com Signed-off-by: Alexei Starovoitov --- lib/buildid.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) (limited to 'lib') diff --git a/lib/buildid.c b/lib/buildid.c index df06e492810d..aaf61dfc0919 100644 --- a/lib/buildid.c +++ b/lib/buildid.c @@ -108,18 +108,21 @@ const void *freader_fetch(struct freader *r, loff_t file_off, size_t sz) */ folio_sz = folio_size(r->folio); if (file_off + sz > r->folio_off + folio_sz) { - int part_sz = r->folio_off + folio_sz - file_off; - - /* copy the part that resides in the current folio */ - memcpy(r->buf, r->addr + (file_off - r->folio_off), part_sz); - - /* fetch next folio */ - r->err = freader_get_folio(r, r->folio_off + folio_sz); - if (r->err) - return NULL; - - /* copy the rest of requested data */ - memcpy(r->buf + part_sz, r->addr, sz - part_sz); + u64 part_sz = r->folio_off + folio_sz - file_off, off; + + memcpy(r->buf, r->addr + file_off - r->folio_off, part_sz); + off = part_sz; + + while (off < sz) { + /* fetch next folio */ + r->err = freader_get_folio(r, r->folio_off + folio_sz); + if (r->err) + return NULL; + folio_sz = folio_size(r->folio); + part_sz = min_t(u64, sz - off, folio_sz); + memcpy(r->buf + off, r->addr, part_sz); + off += part_sz; + } return r->buf; } -- cgit v1.2.3